JP4118667B2 - Webbing take-up device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a webbing take-up device that normally allows the take-out and withdrawal of an occupant-constrained webbing and prevents the withdrawal of the webbing in a predetermined case such as when the vehicle is at a speed limit.
[0002]
[Prior art]
Generally, a webbing take-up device includes a frame formed in a substantially U shape in plan view and fixed to a vehicle, and a take-up shaft is rotatable between a pair of opposed leg plates of the frame. It is supported. Specifically, a spool provided in a central portion in the axial direction of the take-up shaft and wound with a webbing for restraining an occupant in layers is positioned between a pair of leg plates of the frame, and coaxially from the axial end of the spool. The projecting support shaft is rotatably supported by a bearing portion attached to the leg plate.
[0003]
In the webbing take-up device, the webbing take-up / draw-out is usually free because the spool is rotatable. On the other hand, the webbing take-up device is provided with locking means for preventing rotation of the take-up shaft (spool) in the webbing withdrawal direction in a predetermined case such as when the vehicle is suddenly decelerated or when the webbing is suddenly pulled out. Thereby, in the webbing retractor, for example, the restraining force of the occupant by the webbing during the rapid deceleration of the vehicle is improved against the webbing pulling output by the body of the occupant trying to move to the front side of the vehicle due to inertia in the sudden deceleration state. It has become.
[0004]
Further, some webbing take-up devices include an energy absorption mechanism that absorbs energy by allowing a predetermined amount of webbing to be drawn after the lock means prevents rotation of the take-up shaft in the webbing drawing direction. In this type of webbing take-up device, the lock base that is prevented from rotating in the webbing pull-out direction by the locking means in the above predetermined case is connected to the spool via the torsion bar, and the torsion bar is usually twisted. The lock base rotates with the spool. On the other hand, when the rotation of the lock base in the webbing withdrawal direction is prevented, the spool rotates in the webbing withdrawal direction while twisting the torsion bar. Thereby, the movement energy ahead of a passenger | crew is absorbed by the torsional load of a torsion bar. Such a lock base is disposed at one end of the spool in the axial direction.
[0005]
Hereinafter, an example of the locking means applied to each of the above configurations will be briefly described.
[0006]
The lock means includes a lock plate disposed in a recess that is recessed in the end surface of the spool or lock base of the winding shaft and opens radially outward. The lock plate has ratchet teeth formed at the tip thereof, a non-engagement position where the ratchet teeth are received in the recess, and the ratchet teeth projecting radially outward from the opening of the recess to form on the leg plate of the frame An engagement position that meshes with the ratchet teeth of the ratchet hole formed can be selectively taken. When the lock plate is located at the engagement position, rotation of the spool or the lock base in the webbing pull-out direction is prevented.
[0007]
In addition, a lock wheel is provided on the opposite side of the lock plate from the lock base so as to be rotatably supported by a support shaft of the take-up shaft. The lock ring has a guide groove for inserting a guide pin protruding along the axial direction of the take-up shaft from the lock plate, and the guide pin is inserted in the guide groove in the webbing pull-out direction by the urging member. By being energized, it normally follows the rotation of the spool or the lock base (rotates integrally). In this state, the lock plate is held in the non-engagement position. That is, the lock plate is normally held at the non-engagement position by the biasing force of the biasing member.
[0008]
Further, the lock ring is prevented from rotating in the webbing pull-out direction in the predetermined case, and the spool or lock base is prevented from rotating in the webbing pull-out direction against the biasing force of the biasing member. When relative rotation occurs between the guide plate and the guide pin, the guide pin is guided along the guide groove, and the lock plate is moved to the engagement position (against the biasing force of the biasing member).
[0009]
In the webbing take-up device provided with the locking means described above, when the vehicle is suddenly decelerated or when the webbing is suddenly pulled out, the rotation of the locking wheel in the webbing drawing direction is prevented, and the guide of the locking wheel that rotates relative to the spool or the lock base. The guide pin is guided in the groove and the lock plate reaches the engagement position, and the ratchet teeth mesh with the ratchet teeth of the frame. This prevents the spool or the lock base from rotating in the webbing pull-out direction. Further, in the configuration provided with the lock base (energy absorption mechanism), the webbing pulling output by the occupant's inertial force or the like allows the torsion bar to be twisted while allowing the webbing to be pulled out, and the energy to move the occupant forward is absorbed. The acting external force is alleviated.
[0010]
By the way, the urging member that urges the lock ring in the webbing pull-out direction or holds the lock plate in the non-engagement position has one end engaged with the lock ring or the lock plate and the other end spool or lock base. It is locked to. That is, the urging member whose one end is locked to the lock ring urges the lock ring in the webbing pull-out direction and holds the lock plate in the non-engagement position via the lock ring, and the one end is locked. The urging member locked to the plate holds the lock plate in the non-engagement position and urges the lock wheel in the webbing pull-out direction via the lock plate.
[0011]
And the structure which used the compression coil spring as such an urging | biasing member is known (for example, refer patent document 1). The compression coil spring mounting structure will be described with reference to FIG.
[0012]
As shown in FIG. 7, the lock ring 100 includes an insertion hole 106 that allows the compression coil spring 102 to pass to the lock base (spool) 104 side, and a spring that protrudes in the axial direction along the longitudinal edge of the insertion hole. A box 108 is provided, and one end portion of the compression coil spring 102 is inserted into the spring box 108 to be locked.
[0013]
On the other hand, the end surface of the lock base 104 is provided with an arcuate spring accommodating portion 110 into which the compression coil spring 102 is deformably accommodated and into which the spring box 108 can be moved relative to the relative rotation. A spring whose width is narrowed at an end portion of the spring accommodating portion 110 facing the spring box at the normal time corresponding to the diameter of the compression coil spring 102 and the other end portion of the compression coil spring 102 enters and is locked. A receiving recess 112 is provided continuously.
[0014]
As described above, in this compression coil spring mounting structure, the compression coil spring 102 can be easily inserted from the insertion hole 106 of the lock ring 100 in a state where the spring box 108 of the lock ring 100 is inserted into the spring accommodating portion 110 of the lock base 104. And the attached compression coil spring 102 is difficult to come off. Note that the cover 116 provided with the through holes 114 is a cover for preventing a lock plate from falling off (not shown).
[0015]
Moreover, although illustration is abbreviate | omitted, the structure which used the torsion spring (torsion coil spring) as an urging | biasing member is also known (for example, refer patent document 2). In this configuration, a first recess into which the annular portion of the torsion spring enters around the base of the support shaft on the axial end surface of the spool (lock base) is provided, and the second recess is further formed in an arc shape in the first recess. Engage one end part of the torsion spring with the support protrusion of the lock ring that has entered, and engage the other end part of the torsion spring with the wall part of the first recess (the wall part of which the opening edge in the axial direction is partially covered) It is combined.
[0016]
[Patent Document 1]
JP 2000-302010 A
[Patent Document 2]
Japanese Patent Laid-Open No. 2002-19578
[0017]
[Problems to be solved by the invention]
However, in the conventional webbing take-up device as described above, the urging member is disposed between the lock ring or lock plate and the spool or lock base so as to perform its function. In addition to projecting the support protrusions, it is necessary to provide the spring accommodating part, the spring receiving recessed part or the first recessed part or the second recessed part on the spool or the lock base, so that the structure (shape) of the parts is complicated and the body size is large. there were.
[0018]
Complicated component shapes generally complicate the mold structure such as a spool or lock base configured by die casting, a lock ring configured by resin molding, etc., and increase the processing cost of each component, that is, a webbing take-up device Cause high costs. In addition, the large size of each component is a cause of hindering downsizing of the entire webbing take-up device.
[0019]
An object of the present invention is to obtain a webbing take-up device having a simple structure for attaching an urging member that normally holds a lock member in a non-engagement position with a frame in consideration of the above facts.
[0020]
[Means for Solving the Problems]
In order to achieve the above object, a webbing take-up device according to the invention described in claim 1 is coaxially projected from an axial end of a take-up portion around which a passenger-restraining webbing is wound so as to be able to be taken out and pulled out. The support shaft includes a winding shaft that is rotatably supported by a frame supported by the vehicle body, and a guide protrusion that is disposed at an axial end portion of the winding portion and protrudes along the axial direction. A non-engagement position with the frame by movement along a plane perpendicular to the axial direction, and an engagement position that engages with the frame and prevents the winding shaft from rotating in the webbing pull-out direction. And a biasing member having one end locked to the support shaft and the other end locked to the guide protrusion, and holding the lock member in the disengaged position by a biasing force. And a guide groove for inserting the guide protrusion. And a, a guide member is moved to the engaged position said locking member is guided along the guide projection into the guide groove in a predetermined case.
[0021]
In the webbing take-up device according to claim 1, the take-up shaft is normally rotatable by the lock member being held in the non-engagement position by the urging force of the urging member, and the webbing take-up and withdrawal is free. Has been. On the other hand, in a predetermined case such as when the vehicle is suddenly decelerated or when the webbing is suddenly pulled out, the guide member guides the guide protrusion of the lock member along the guide groove, so that the lock member is attached to the biasing member. It moves to the engagement position against the force. Then, the lock member is engaged with the frame, and the rotation of the winding shaft in the webbing pull-out direction is prevented.
[0022]
Here, since the one end of the biasing member is locked to the spindle of the winding shaft and the other end is locked to the guide protrusion of the lock member, in other words, the biasing member is Since different ends are locked to the support shaft having the function of supporting the shaft on the frame and the guide projection having the function of guiding the lock member to the guide means, the lock member and the winding shaft (winding portion) It is not necessary to form a locking portion of the urging member on the axial end surface of the urging member. In other words, since the urging member is attached by utilizing a part necessary for the functions of the winding shaft and the locking member, the winding shaft and the locking member have a conventional concave portion that complicates the shape thereof. There is no need to provide a protrusion, an insertion hole or the like, and the structure (shape) is simplified.
[0023]
For this reason, the winding shaft and the lock member have improved workability and can be reduced in size.
[0024]
Thus, in the webbing take-up device according to the first aspect, the structure for attaching the urging member that normally holds the lock member in the non-engagement position with the frame is simple.
[0025]
Needless to say, the guide means described in claim 1 is not limited to the configuration that follows the rotation of the winding shaft by the urging force of the urging member.
[0026]
A webbing take-up device according to a second aspect of the present invention is the webbing take-up device according to the first aspect, wherein the biasing member is formed in a spiral shape and is inserted into the inner edge portion of the spring shaft. The locking portion locked to the guide protrusion and the arm portion connecting the spring portion and the locking portion are formed along one plane, and the plane is arranged so as to be orthogonal to the axial direction. The guide protrusion is a tension spring that pulls toward the support shaft.
[0027]
3. The webbing take-up device according to claim 2, wherein the tension spring as an urging member has a spring portion formed in a spiral shape, which is one end thereof, inserted into the inner edge of the support shaft and locked to the support shaft. At the same time, in a state where the locking portion, which is the other end connected to the spring portion via the arm portion, is locked to the guide protrusion, the guide protrusion is pulled toward the support shaft side to disengage the lock member. Hold on.
[0028]
Here, in the tension spring, the spring portion, the arm portion, and the locking portion are formed along one plane, and the plane is orthogonal to the axial direction of the winding shaft (so as to be along the end surface of the winding portion). Therefore, the space for arranging the tension spring as the biasing member is small. For this reason, size reduction of a webbing take-up device is achieved.
[0029]
Further, since the spiral spring portion is deformed in a direction in which the spiral is reduced when an urging force in the tensile direction is generated, the internal stress is small and the durability is good (or the durability is increased).
[0030]
A webbing take-up device according to a third aspect of the invention is characterized in that, in the webbing take-up device according to the second aspect, the tension spring is made of a wire.
[0031]
In the webbing take-up device according to claim 3, since the tension spring is formed by the wire along the plane, the thickness of the tension spring is compared with, for example, a configuration in which the tension spring according to claim 2 is a mainspring spring. (Height along the axial direction of the take-up shaft), that is, the arrangement space is further reduced, and the webbing take-up device can be further downsized.
[0032]
A webbing take-up device according to a fourth aspect of the present invention is the webbing take-up device according to any one of the first to third aspects, wherein the guide member is pivotally supported by the support shaft so as to be relatively rotatable. Usually, the urging force of the urging member follows the rotation of the winding shaft in the webbing pull-out direction, and in the predetermined case, the rotation of the webbing pull-out direction is prevented and the rotation relative to the winding shaft causes the rotation. The lock member is configured to move the lock member to the engagement position.
[0033]
In the webbing take-up device according to claim 4, the lock ring as the guide member normally engages the lock member following the rotation of the take-up shaft in the webbing pull-out direction by the urging force of the urging member (tensile spring). There is no movement to the position. On the other hand, when the rotation of the lock ring in the webbing pull-out direction is prevented in the predetermined case, a relative rotation occurs between the lock ring and the winding shaft, and the lock ring moves along the guide groove by the relative rotation. The guide protrusion is guided to move the lock member to the engagement position.
[0034]
As described above, since the urging member urges the lock ring in the above direction via the lock member, for example, after the rotation prevention of the winding shaft, the rotation prevention state of the lock ring in the webbing pull-out direction is released. It is also possible to make the webbing take-up device return to the normal state by rotating the take-up shaft in the webbing take-up direction.
[0035]
That is, the structure with a simple structure for attaching the urging member is a webbing winding having a preferable structure in which the urging force of the urging member causes the lock ring as the guide means to follow the rotation of the winding shaft in the webbing pull-out direction. The present invention is also preferably applied to a taking device.
[0036]
A webbing take-up device according to a fifth aspect of the present invention is the webbing take-up device according to any one of the first to fourth aspects, wherein the take-up portion is a spool around which the webbing is wound, A lock base disposed between the spool and the lock member so as to be rotatable relative to the spool, and prevented from rotating in the webbing pull-out direction when the lock member is located at the engagement position. It is characterized by the configuration.
[0037]
In the webbing take-up device according to the fifth aspect, the take-up portion of the take-up shaft has a spool and a lock base disposed between the spool and the lock member. When the lock member reaches the engagement position, the rotation of the lock base in the webbing pull-out direction is prevented. By providing an energy absorbing member (for example, a torsion bar or a friction member) between the lock base and the spool, while allowing a predetermined amount of webbing to be pulled out by relative rotation between the lock base and the spool, Inertial energy is absorbed.
[0038]
Thus, the structure with a simple structure for attaching the urging member is also suitably applied to a webbing take-up device provided with an energy absorbing mechanism.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
A webbing take-up device 10 according to an embodiment of the present invention will be described with reference to FIGS. In addition, when the arrow A is shown in FIG. 1 thru | or FIG. 6, this arrow A direction has shown the webbing extraction | drawer direction (rotation direction).
[0040]
FIG. 1 is a sectional view showing the overall configuration of a webbing take-up device 10 according to the present embodiment. As shown in this figure, the webbing take-up device 10 includes a frame 14 formed in a substantially U shape in plan view, and the frame 14 is fixed to the vehicle body side. The frame 14 includes a first leg plate 16 and a second leg plate 18 that extend in parallel to each other, and the spool 12 as a winding portion that is manufactured by die casting between the first leg plate 16 and the second leg plate 18. Is rotatably supported.
[0041]
The spool 12 is disposed on the side of the first leg plate 16 (a cylindrical spool shaft 12A constituting the shaft core portion) and a pair of flange portions (hereinafter referred to as the first leg plate 16) formed at both ends of the spool shaft 12A. The flange portion is referred to as the “first flange portion 12B” and the flange portion disposed on the second leg plate 18 side is referred to as the “second flange portion 12C”). ing. One end of the webbing W is engaged with the spool shaft 12A of the spool 12 and the webbing W is wound around. The webbing W can be wound and pulled out of the spool 12 by the rotation of the spool 12. .
[0042]
A torsion bar insertion hole 20 is formed in the shaft core portion of the spool shaft 12A. On the first flange portion 12B side of the torsion bar insertion hole 20, a concave lock base receiving portion 22 having a larger diameter than the torsion bar insertion hole 20 is formed coaxially. The lock base receiving portion 22 includes a concave body 22A that occupies most of the lock base, and a concave terminal portion 22B having a larger diameter than the concave body 22A.
[0043]
The lock base receiving portion 22 is mounted with the lock base 24 being prevented from coming off. The lock base 24 is attached by inserting a stopper (prevention member) (not shown) formed in a U shape in front view from the direction perpendicular to the axis after inserting the lock base 24 into the lock base receiving portion 22. The method is taken.
[0044]
The lock base 24 is formed in a cylindrical shape with a hook, and has a base portion 24A fitted into the concave body 22A of the lock base receiving portion 22, a diameter larger than the base portion 24A, and a concave end portion of the lock base receiving portion 22. The intermediate portion 24B is fitted into 22B, and the holding portion 24C has a larger diameter than the intermediate portion 24B and is disposed in contact with the outer surface of the first flange portion 12B. Further, a hexagonal hole-shaped fitting hole 26 is formed in a portion of the lock base 24 excluding the outer end of the shaft core portion. Further, the outer end of the shaft core portion is mutually connected to the shaft core portion of the fitting hole 26. And a small hole 28 having a smaller diameter than that of the small hole 28 is formed.
[0045]
On the other hand, a recessed sleeve receiving portion 30 having a larger diameter than the torsion bar insertion hole 20 is formed on the second flange portion 12C side of the torsion bar insertion hole 20 of the spool shaft 12A. A female spline is formed on the inner peripheral portion of the sleeve receiving portion 30, a male spline is formed on the outer peripheral portion of the sleeve receiving portion 30, and a hexagonal hole-shaped fitting hole 32 is formed on the shaft core portion. The sleeve 34 is fitted. Thereby, the sleeve 34 always rotates integrally with the spool 12.
[0046]
A support shaft 34A is coaxially provided from the outer end surface of the sleeve 34, and the support shaft 34A is rotatably supported by a bearing portion of a cover member (not shown) fixedly attached to the leg plate 18. It is like that. Note that the inner end of a biasing means (spring spring) that biases the spool 12 to rotate in the webbing take-up rotation direction is locked to the tip of the support shaft 34A via an adapter (not shown). The sleeve 34 having the above-described configuration is one of the components of a pretensioner mechanism that instantaneously rotates the spool 12 in the webbing take-up direction when the vehicle suddenly decelerates.
[0047]
The lock base 24 and the sleeve 34 described above are connected to each other by a torsion bar 36. The torsion bar 36 includes a shaft portion 36A constituting the main portion thereof, a hexagonal head portion 36B formed at one end portion of the shaft portion 36A, and a hexagonal fitting formed at the other end portion of the shaft portion 36A. The portion 36C and a support shaft 36D that has a smaller diameter than the shaft portion 36A and extends coaxially with the shaft portion 36A from the shaft core portion of the fitting portion 36C.
[0048]
A head portion 36B of the torsion bar 36 is fitted in a hexagonal hole-shaped fitting hole 32 formed in the sleeve 34, and a fitting portion 36C of the torsion bar 36 is formed in a hexagonal hole shape formed in the lock base 24. It is fitted in the fitting hole 26. Thereby, the torsion bar 36 is integrated with the spool shaft 12 </ b> A via the lock base 24 and the sleeve 34. In this state, the shaft portion 36 </ b> A of the torsion bar 36 is positioned in the torsion bar insertion hole 20, and the support shaft 36 </ b> D passes through the small hole 28 of the lock base 24.
[0049]
In the above configuration, the spool 12, the lock base 24, the sleeve 34, and the torsion bar 36 correspond to the “winding shaft” in the present invention.
[0050]
As shown in FIGS. 2 and 3, an internal ratchet 38 is formed by punching on the upper side of the first leg plate 16 of the frame 14 described above. The ratchet teeth 38A of the internal tooth ratchet 38 are set to have high strength.
[0051]
A holding portion 24 </ b> C of the lock base 24 is disposed on the radially inner side of the internal tooth ratchet 38. A plate housing portion 40 is recessed in the outer end surface of the holding portion 24C. The plate accommodating portion 40 has an opening 40A opened on the outer peripheral surface of the holding portion 24C, and allows the locking teeth 42C of the lock plate 42 described below to advance and retract from the opening 40A.
[0052]
On the other hand, the inner edge portion of the plate accommodating portion 40 is defined by a wall portion 40B, and a stopper portion 40C for restricting the position of the lock plate 42 projects from the wall portion 40B toward the opening portion 40A. Further, a rotation shaft 41 projects from one end of the holding portion 24 </ b> C in the plate housing portion 40 and is used for supporting the lock plate 42.
[0053]
The plate accommodating portion 40 accommodates a lock plate 42 as a lock member. Further, a thin disc-shaped lock cover 44 is attached to the outer surface of the holding portion 24C of the lock base 24 (the axially open end of the plate housing portion 40) to prevent the lock plate 42 from falling off. It has been.
[0054]
The lock plate 42 can mesh with a metal plate main body 42A, a shaft hole 42B provided at one end of the plate main body 42A, and a ratchet tooth 38A of the internal tooth ratchet 38 formed at the other end of the plate main body 42A. The high-strength lock teeth 42C and the guide pins 42D as guide protrusions erected from the vicinity of the lock teeth 42C in the plate main body 42A.
[0055]
The lock plate 42 is accommodated in the plate accommodating portion 40 by inserting the rotation shaft 41 of the lock base 24 into the shaft hole 42B. In this state, the axial direction of the guide pin 42D is parallel to the axial direction of the lock base 24 (support shaft 36D).
[0056]
Then, the lock plate 42 is a ratchet that causes the plate main body 42A to abut against the stopper portion 40C and the lock teeth 42C are positioned inside the plate accommodating portion 40 (inside the opening 40A) by turning around the turning shaft 41. A non-engagement position with the teeth 38A (non-engagement position, see FIG. 2), and a mesh position (see FIG. 3) with which the locking teeth 42C protrude from the opening 40A of the plate housing portion 40 and mesh with the ratchet teeth 38A. This is a configuration that can be taken selectively. The lock plate 42 located at the meshing position prevents the lock base 24 from rotating in the webbing pull-out direction.
[0057]
The lock plate 42 described above is normally held in the plate accommodating portion 40, that is, in the non-engagement position by the urging force of the return spring 70. The return spring 70 will be described later.
[0058]
Further, at a position adjacent to the outside of the lock base 24 (lock cover 44), a V gear 46 as a lock wheel formed in a substantially disc shape having a larger diameter than this is disposed. As shown in FIG. 5, a cylindrical boss 48 is formed on the shaft core portion of the V gear 46, and is pivotally supported on the support shaft 36 </ b> D of the torsion bar 36 so as to be relatively rotatable. Further, a plurality of lock teeth 46A are integrally formed at equal intervals on the outer peripheral portion of the V gear 46 formed in a short cylindrical shape.
[0059]
The V gear 46 is formed with a guide hole 50 as a guide groove having a shape bent at opposite ends, and a guide pin 42D erected from the lock plate 42 is inserted into the guide hole 50. Yes. The guide pin 42D of the lock plate 42 positioned at the non-engagement position by the urging force of the return spring 70 is positioned at the end of the guide hole 50 opposite to the arrow A side. In this state, the V gear 46 is urged in the webbing pull-out direction (arrow A direction) by the urging force of the return spring 70 acting via the lock plate 42. Thereby, the V gear 48 normally rotates integrally with the spool 12.
[0060]
On the other hand, relative rotation in the direction in which the phase of the webbing pull-out direction of the spool 12 advances with respect to the V gear 46 (rotation against the urging force of the return spring 70) occurs between the spool 12 (winding shaft) and the V gear 46. In this case, the V gear 46 is configured such that the guide hole 50 guides the guide pin 42D and moves the lock plate 42 to the meshable position (engagement position).
[0061]
When the lock plate 42 reaches the meshable position, the lock tooth 42C is drawn to the bottom of the ratchet tooth 38A by the shape of the ratchet tooth 38A by the operation of the spool 12 rotating in the webbing pull-out direction. 42C is completely meshed with the ratchet teeth 38A (moves to the meshing position by a self-locking action).
[0062]
A known acceleration sensor 52 for VSIR shown in FIG. 6 is disposed below the V gear 46. In FIG. 1, the acceleration sensor 52 is not shown. In the acceleration sensor 52, when the vehicle suddenly decelerates, the ball 54 rolls on the sensor housing 56 to swing the sensor lever 58, and the lock claw 58A of the sensor lever 58 is engaged with the lock teeth 46A of the V gear 46. It has become so. This engagement prevents the V gear 46 from rotating in the webbing pull-out direction.
[0063]
Further, as shown in FIG. 1, a resin sensor holder 60 is disposed outside the first leg plate 16 of the frame 14 described above, and a shape similar to the sensor holder 60 is formed outside the sensor holder 60. The sensor cover 62 made of resin is fitted. The sensor holder 60 and the sensor cover 62 are integrally attached to the first leg plate 16 of the frame 14.
[0064]
The sensor holder 60 is configured to include a holder main body portion 64 formed in a substantially cup shape, and a sensor holding portion 66 in a substantially rectangular frame shape formed on the lower edge side of the holder main body portion 64. A cylindrical bearing portion 68 is integrally formed on the shaft core portion of the holder main body portion 64, and a support shaft 36 </ b> D of the torsion bar 36 is pivotally supported on the bearing portion 68. Further, the acceleration sensor 52 described above is inserted and held in the sensor holding portion 66.
[0065]
Further, an inner tooth 64 </ b> A that can be engaged with a WSIR pawl (not shown) that is pivotally supported by the pawl shaft 46 </ b> B of the V gear 46 described above is integrally formed on the inner peripheral portion of the holder main body 64. At the time of sudden withdrawal, the pawl which cannot follow the rotation of the V gear 46 is engaged with the internal teeth 64A to prevent the rotation of the V gear 46 in the webbing withdrawal direction.
[0066]
In other words, the V gear 46 is configured to be prevented from rotating in the webbing pull-out direction by the VSIR acceleration sensor 52 when the vehicle is suddenly decelerated, and to be prevented from rotating in the webbing pull-out direction by the pawl when the webbing W is suddenly pulled out. The rotation prevention state in the webbing pull-out direction of the V gear 46 is such that the guide pin 42D presses the hole wall of the guide hole 50 in the direction in which the component force in the direction opposite to the arrow A is generated in association with the self-locking action. By slightly rotating the V gear 46 in the direction opposite to the arrow A, the sensor lever 58 returns to the initial position due to gravity, or the pawl returns to the initial position due to the urging force of a spring (not shown) so as to be released. It has become.
[0067]
Next, the return spring 70 will be described. As shown also in FIG. 4, the return spring 70 includes a spring portion 70A formed in a spiral shape, a locking portion 70B formed in a hook shape, and an arm portion 70C that connects the spring portion 70A and the locking portion 70B. It consists of and. The spring portion 70A, the locking portion 70B, and the arm portion 70C are integrally formed by bending the wire so as to be along one plane. That is, the return spring 70 is formed two-dimensionally as a whole, and in particular, the spiral spring portion 70A is formed so that its diameter continuously changes on the plane.
[0068]
The return spring 70 has the support shaft 36D inserted inside the inner edge of the spring portion 70A, and the guide pin 42D of the lock plate 42 is inserted into the locking portion 70B (the locking portion 70B is hooked on the guide pin 42D). In this state, it is disposed between the lock base 24 and the lock cover 44 (not shown in FIG. 4). The spring portion 70A only needs to be inserted into the center portion of the spiral at the end thereof to prevent the spring shaft 70A from falling off in the radial direction, and need not be held by the spring shaft 36D with a spring force.
[0069]
That is, the return spring 70 is disposed along a plane orthogonal to the support shaft 36D (the axis of the lock base 24). The return spring 70 is prevented from falling off in the axial direction (disengagement of the locking portion 70B from the guide pin 42D) by the lock cover 44.
[0070]
In this state, the return spring 70 has a diameter of the spring portion 70A smaller than that in the natural state, and the guide pin 42D is pulled toward the support shaft 36D by the urging force. That is, the return spring 70 is configured to function as a tension spring.
[0071]
Next, the operation of the present embodiment will be described.
[0072]
In the webbing take-up device 10 configured as described above, normally, the lock plate 42 is held in the non-engagement position by the biasing force of the return spring 70, and the V gear 46 is biased in the webbing pull-out direction. The holding state in the non-meshing position (the state shown in FIG. 2) is maintained, and the spool 12, the lock base 24, the sleeve 34, the torsion bar 36, the lock plate 42, and the V gear 46 rotate together. For this reason, usually, the webbing W can be taken out and pulled out freely.
[0073]
On the other hand, when the vehicle suddenly decelerates, the acceleration sensor 52 is activated and the sensor lever 58 is engaged with the lock teeth 46A, or the WSIR pawl pivotally supported by the V gear 46 by the sudden withdrawal of the webbing W is applied to the internal teeth 64A. When engaged, rotation of the V gear 46 in the webbing pull-out direction is prevented. From this state, for example, when the lock base 24 rotates together with the spool 12 against the biasing force of the return spring 70 by the webbing pulling output such as an inertial force forward of the occupant, the lock base 24 and the V A relative rotation occurs with the gear 46.
[0074]
By this relative rotation, the lock plate 42 moves to a position where the guide pin 42D can engage with the ratchet teeth 38A of the frame 14 as the guide pin 42D is guided by the guide hole 50 of the V gear 46. When the lock base 24 further rotates in the webbing pull-out direction, the lock teeth 42C of the lock plate 42 mesh with the ratchet teeth 38A by a self-locking action as shown in FIG.
[0075]
That is, due to the relative rotation between the lock base 24 and the V gear 46, the lock plate 42 reaches the meshing position against the urging force of the return spring 70, and the rotation of the lock base 24 in the webbing pull-out direction is prevented. At this time, when the hole wall of the guide hole 50 is pressed by the guide pin 42D and slightly rotates in the direction opposite to the arrow A, the V gear 46 is released from being prevented from rotating in the webbing pull-out direction. .
[0076]
If the webbing pulling output further acts on the spool 12 from this state, the spool 12 rotates in the webbing pulling direction while twisting the shaft portion 36A of the torsion bar 36, and energy is absorbed by the torsional load of the torsion bar 36. That is, the occupant's inertial energy and the like accompanying the sudden deceleration of the vehicle is absorbed.
[0077]
Further, when the shaft portion 36A of the torsion bar 36 is not broken, when the spool 12 rotates in the webbing take-up direction, the lock base 24 and the V gear 46 rotate following the spool 12, and the lock plate 42 is rotated. Is returned to the non-engagement position by the urging force of the return spring 70 while being guided by the guide hole 50 in the guide pin 42D. Thereby, the webbing W can be pulled out again. In particular, when the pulling force of the webbing W (such as the inertia force of the occupant) is small and the plastic deformation does not occur in the shaft portion 36A of the torsion bar 36, the webbing retractor 10 returns to the completely initial state.
[0078]
In the webbing take-up device 10, when the vehicle deceleration is large, such as in a collision, a pretensioner mechanism (not shown) is activated almost simultaneously with the operation of the acceleration sensor 52, and the spool 12 is rotated in the webbing take-up direction. Then, the webbing W is instantaneously wound and the occupant is restrained at the initial stage of the collision, and then the energy is absorbed by the torsional load of the torsion bar 36 as described above, and the occupant is suitably protected (force limiter action for relaxing external force acting on the occupant) Fulfill).
[0079]
Here, the return spring 70 is locked with a spring portion 70A, which is one end thereof, inserted through the support shaft 36D, and a locking portion 70B, which is the other end, is locked to the guide pin 42D of the lock plate 42. In other words, in other words, the return spring 70 is attached by utilizing the functionally necessary portions of the winding shaft and the lock plate 42 including the spool 12 and the lock base 24, and thus the lock plate 42. In addition, it is not necessary to separately form the locking portion of the urging member on the lock base 24.
[0080]
More specifically, the V gear 46 guides the support shaft 36D having a function of supporting the winding shaft including the spool 12 and the lock base 24 to the frame 14 (sensor holder 60), and the lock plate 42. Since different end portions of the return spring 70 are engaged with the guide pin 42D having a function, the lock plate 42 and the lock base 24 have a concave portion, a protruding portion, an insertion hole, etc., which make the shape complicated. The structure (shape) is simplified. Further, since the V gear 46 is urged by the urging force of the return spring 70 via the lock plate 42, the V gear 46 also has a recess, a protrusion, an insertion hole, or the like that is a locking portion of the return spring 70. There is no need to provide it, and the structure (shape) is simplified.
[0081]
For this reason, the lock base 24, the lock plate 42, and the V gear 46 are improved in workability and can be reduced in size.
[0082]
Thus, in the webbing take-up device according to the present embodiment, the structure for attaching the return spring 70 that normally holds the lock plate 42 in the non-engagement position with the ratchet teeth 38A of the frame 14 is simple.
[0083]
Here, the return spring 70 is formed along the same plane (the spring portion 70A, the locking portion 70B, and the arm portion 70C) as a whole, and the plane is orthogonal to the axial direction of the support shaft 36D. Therefore, the space for arranging the return spring 70 (thickness of the lock base 24) is small. In particular, since the return spring 70 is made of a wire rod, the thickness (height along the axial direction) of the return spring 70, that is, the arrangement space is further reduced. For this reason, size reduction of the webbing take-up device 10 is achieved.
[0084]
Furthermore, since the return spring 70 is deformed in the direction of reducing the diameter of the spring portion 70A and generates a biasing force in the tensile direction, the internal stress is small and the durability is good. In particular, the number of times of durability is remarkably improved as compared with the configuration in which the conventional compression coil spring 102 is deformed not only in the compression direction but also in the direction in which the axis is curved.
[0085]
Furthermore, the return spring 70 is simply operated by causing the support shaft 36D to be inserted into the spring portion 70A by the axial movement of the support shaft 36D and locking the hook-shaped locking portion 70B to the guide pin 42D in this state. Since it is mounted, the mounting operation is easy.
[0086]
In the above-described embodiment, the webbing take-up device 10 has a preferable configuration including the energy absorption mechanism including the lock base 24, the torsion bar 36, and the like. However, the present invention is not limited to this, and the webbing winding is not limited thereto. The take-up device 10 may be configured not to include an energy absorption mechanism. In this case, for example, the end portion (first flange portion 12B) of the spool 12 provided with the plate accommodating portion 40, the rotation shaft 41, and the like is disposed inside the internal tooth ratchet 38, and the support shaft extends from the end portion of the spool 12. It can be set as the structure which projects 36D integrally. Needless to say, the energy absorbing member that generates resistance against the relative rotation between the spool 12 and the lock base 24 is not limited to the torsion bar 36.
[0087]
In the above embodiment, the V gear 46 is urged in the webbing pull-out direction by the urging force of the return spring 70 to follow or return to the state of following the lock base 24 (spool 12). However, the present invention is not limited to this. For example, when the V gear 46 that can follow the rotation of the lock base 24 or the like by mechanical engagement or adhesion is used in a predetermined case. It may be configured to rotate relative to the lock base 24 or the like by the engagement or the breakage of the bonded portion. Therefore, the present invention is not limited to a preferable configuration that allows the webbing W to be pulled out again after the spool 12 or the lock base 24 is prevented from rotating in the webbing pull-out direction.
[0088]
Furthermore, in the above-described embodiment, the return spring 70 is preferably formed along the same plane as a whole, but the present invention is not limited to this. For example, the spring portion 70A is formed in a coil shape. Also good. Moreover, the return spring 70 is not limited to the preferable structure which consists of wires, For example, the spring part 70A is good also as a mainspring spring. That is, it is sufficient for the biasing member in the present invention to have one end locked to a portion corresponding to the guide pin 42D and the other end locked to a portion corresponding to the support shaft 36D.
[0089]
Furthermore, in the above-described embodiment, the return spring 70 is preferably disposed between the lock base 24 and the lock cover 44. However, the present invention is not limited to this. The return spring 70 may be disposed on the side opposite to the lock cover 44. In this case, the spring portion 70A may be locked to the outer peripheral portion of the boss 48 of the V gear 46 (the portion corresponding to the support shaft 36D).
[0090]
【The invention's effect】
As described above, the webbing take-up device according to the present invention has an excellent effect that the structure for attaching the urging member that normally holds the lock member in the non-engagement position with the frame is simple.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an overall configuration of a webbing take-up device according to an embodiment of the present invention.
FIG. 2 is a side view showing an unlocked state of the webbing take-up device according to the embodiment of the present invention.
FIG. 3 is a side view showing a locked state of the webbing retractor according to the embodiment of the present invention.
FIG. 4 is an exploded perspective view showing a return spring mounting structure constituting the webbing take-up device according to the embodiment of the present invention.
FIG. 5 is a plan view of a V gear constituting the webbing take-up device according to the embodiment of the present invention.
FIG. 6 is a side view of an acceleration sensor constituting the webbing take-up device according to the embodiment of the present invention.
FIG. 7 is an exploded perspective view showing a return spring mounting structure in a conventional webbing take-up device.
[Explanation of symbols]
10 Webbing take-up device
12 Spool (winding part, winding shaft)
14 frames
24 Lock base (winding part)
34 Sleeve (winding shaft)
36 Torsion bar (winding shaft)
36D spindle
42 Lock plate (locking member, take-up shaft)
42D Guide pin (guide protrusion)
46 V gear (guide member, lock ring)
50 Guide hole (Guide groove)
70 Return spring (biasing member, tension spring)
70A Spring part
70B Locking part
70C arm part

Claims (5)

A take-up shaft that is rotatably supported by a frame supported by the vehicle body on a support shaft that protrudes coaxially from an axial end of a take-up portion around which a webbing for restraining an occupant is wound so as to be taken out and pulled out When,
A guide protrusion disposed along the axial direction of the winding portion and projecting along the axial direction, and disengaged from the frame by movement along a plane perpendicular to the axial direction. And a lock member that can be engaged with the frame and take an engagement position that prevents the winding shaft from rotating in the webbing pull-out direction;
A biasing member having one end locked to the support shaft and the other end locked to the guide protrusion, and holding the lock member in the non-engagement position by a biasing force;
A guide member that guides the guide projection along the guide groove and moves the lock member to the engagement position in a predetermined case;
A webbing take-up device comprising: The biasing member,
A spring portion that is formed in a spiral shape and allows the support shaft to be inserted inside the inner edge portion, a locking portion that is locked to the guide protrusion, and an arm portion that connects the spring portion and the locking portion are flat. And a tension spring that is arranged so that the plane is perpendicular to the axial direction and pulls the guide projection toward the support shaft.
The webbing take-up device according to claim 1. The webbing take-up device according to claim 2, wherein the tension spring is made of a wire. The guide member;
The shaft is supported so as to be rotatable relative to the support shaft, and normally follows the rotation of the winding shaft in the webbing pull-out direction by the biasing force of the biasing member, and the rotation in the webbing pull-out direction is prevented in the predetermined case. And a lock wheel that moves the lock member to the engagement position by relative rotation with the winding shaft.
The webbing take-up device according to any one of claims 1 to 3, wherein the webbing take-up device is provided. The winding part
A spool around which the webbing is wound;
A lock base disposed between the spool and the lock member so as to be rotatable relative to the spool, and prevented from rotating in the webbing pull-out direction when the lock member is located at the engagement position;
The webbing take-up device according to claim 1, wherein the webbing take-up device according to claim 1 is included.

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