JP3689515B2 - Seat belt retractor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a retractor (winding device) for a seat belt device, and more particularly to a seat belt retractor provided with an energy absorbing mechanism.
[0002]
[Prior art]
Conventionally, a seat belt retractor for safely holding a vehicle occupant or the like in a seat has an emergency lock mechanism that physically locks the retractor by inertial sensing means that reacts to sudden acceleration, collision or deceleration. Therefore, an emergency lock retractor that effectively and safely restrains the occupant is used.
[0003]
As such an emergency lock type retractor, for example, a webbing is used as in the retractor for a seat belt disclosed in Japanese Patent Laid-Open No. 50-79024, Japanese Patent Publication No. 59-21624, and Japanese Utility Model Publication No. 2-45088. Locking means capable of preventing rotation of the winding shaft in the webbing pull-out direction by a locking member disposed at one end of the winding shaft to be wound engaged with the engaged portion of the retractor base in the event of a vehicle emergency There is something with.
[0004]
And in the said locking means, it was formed in the latching engagement part formed in the winding shaft through-hole of the retractor base which a winding shaft penetrates, or the internal-tooth plate attached to the winding shaft through-hole. While ratchet teeth are used as engaged parts, lock plates and locking claws that rotate with the take-up shaft are used as lock members, and these lock members and engaged parts are engaged in a vehicle emergency. The winding shaft is configured to prevent rotation in the webbing pull-out direction.
[0005]
On the other hand, when the impact force due to the collision is extremely large, the webbing tension increases with the lapse of time after the collision, so that a rapid deceleration occurs in the occupant's body, and the load on the occupant from the webbing becomes extremely large. Therefore, when the load acting on the webbing exceeds a preset value, the seat belt is extended by a predetermined amount to provide an energy absorption mechanism that absorbs the impact generated on the occupant's body, thus ensuring the occupant's body more reliably. Various types of seat belt devices that are designed to be protected are proposed. As a seat belt retractor having such a configuration, “especially an energy absorbing device for a safety belt” described in Japanese Patent Application Laid-Open No. 46-7710 is known.
[0006]
In the energy absorbing device, a winding member (bobbin) for a portion where the energy absorbing device transmits force, and a holder (retractor base) that is rotatable relative to the winding member. A torsion bar (plastic deformation means) is arranged between the holder and the winding member. In a vehicle emergency, a gear (lock member) disposed at one end of the torsion bar is locked by the locking lever and is connected to the holder so as not to rotate. On the other hand, the other end of the torsion bar is previously coupled to the winding member so as not to rotate. Therefore, when torque in the webbing pull-out direction further acts on the winding member, the torsion bar is twisted around its own axis and plastically deformed, so that the collision energy acting on the occupant's body is absorbed as deformation work of the torsion bar. Is done.
[0007]
[Problems to be solved by the invention]
By the way, when the energy absorbing device for a safety belt described in JP-A-46-7710 is used for an automatic safety belt (emergency lock type retractor), both end portions of the torsion bar can turn freely on the holder block. By being supported, the winding member around which the webbing is wound is rotatably attached to the holder block.
[0008]
However, if the take-up member receives a large force in the webbing pull-out direction due to the load acting on the webbing, a shearing force acts between both ends of the torsion bar supported by the holder block with the support part of the holder block. There is a possibility that both ends of the torsion bar are sheared and the winding member comes out of the holder block.
[0009]
Also, depending on the state of support of one end of the winding member that is rotatably supported by the gear, when the winding member receives a large force in the webbing pull-out direction due to the load acting on the webbing, both side plates of the holder block Since a bending force may be applied to the torsion bar due to a force that spreads the torsion bar, the torsion bar to which the bending force is applied together with the torsional force has a lower twist limit than the predetermined value.
[0010]
Accordingly, an object of the present invention is to solve the above-mentioned problems, and it is possible to increase the torsional limit amount of the torsion rod and to prevent the bobbin from coming out by preventing the torsion rod from being damaged. A retractor for a seat belt provided with an absorption mechanism is provided.
[0011]
[Means for Solving the Problems]
The above object of the present invention is to provide a bobbin around which a webbing is wound, a lock member which is engaged with a retractor base and prevents rotation in the webbing pull-out direction in a vehicle emergency, and a retractor base inserted through the bobbin. The seatbelt retractor includes a torsion bar that is rotatably supported by one end and is integrally coupled to the bobbin on one end side and is integrally coupled to the lock member on the other end side. And
The other end side of the torsion bar is inserted into the lock member side end of the bobbin through a fitting recess that is recessed to receive a cylindrical boss protruding from the end surface of the lock member. A bearing bush that enhances slidability is fitted to at least the shaft support portion in the contact portion between the bobbin and the lock member .
This is achieved by a seatbelt retractor characterized in that the outer peripheral portion of the lock member faces the inner periphery of a through hole opened in the side plate of the retractor base .
[0012]
According to the above configuration, when the bobbin receives a large force in the webbing pull-out direction due to the load acting on the webbing, the end of the bobbin on the lock member side moves in the webbing pull-out direction via the boss part of the lock member and the bearing bush. Since it is regulated, bending force and shearing force do not act on the torsion bar inserted through the bobbin. In addition, when a bearing bush that enhances slidability is fitted to the shaft support between the bobbin and the lock member, the torsion bar is twisted to cause relative rotation between the bobbin and the lock member. The energy absorption load can be stabilized by reducing the frictional resistance of the shaft support.
[0013]
Preferably, the bearing bush is made of a plastic having excellent slidability such as polyoxymethylene or fluororesin, or a hard and smooth metal such as stainless steel or a bearing metal.
Further, the above object of the present invention is to provide a bobbin around which a webbing is wound, a lock member that is engaged with a retractor base and prevents rotation in the webbing pull-out direction in the event of a vehicle emergency, and a bobbin that is inserted through the bobbin. A seat belt retractor comprising a torsion bar that is rotatably supported by the tractor base and is integrally coupled to the bobbin at one end and integrally coupled to the lock member at the other end. Because
The other end side of the torsion bar is inserted into the lock member side end of the bobbin through a fitting recess that is recessed to receive a cylindrical boss protruding from the end surface of the lock member. A bearing bush capable of being compressed and deformed by a bearing load of a predetermined value or more is fitted to at least the shaft support portion in the contact portion between the bobbin and the lock member.
This is achieved by a seatbelt retractor characterized in that the outer peripheral portion of the bobbin lock member side end portion is opposed to the inner peripheral edge of a through hole opened in the side plate of the retractor base.
[0014]
According to the above configuration, when the bobbin receives a large force in the webbing pull-out direction due to the load acting on the webbing, the lock member side end of the bobbin moves in the webbing pull-out direction via the boss part of the lock member and the bearing bush. Therefore, the torsion rod inserted through the bobbin is not subjected to bending force or shearing force during the energy absorbing operation. In addition, after the energy absorbing operation is completed, the outer periphery of the bobbin abuts against the inner peripheral edge of the retractor base and the movement in the webbing pull-out direction is restricted due to the compression deformation of the bearing bush due to the bearing load exceeding a predetermined value. The bobbin can be prevented from coming out of the retractor.
[0015]
Preferably, the inner peripheral edge of the through hole is opposed to the outer peripheral portion of the bobbin locking base side end portion by drawing, burring or semi-shearing the retractor inward.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a front longitudinal sectional view of a seatbelt retractor 100 according to a first embodiment of the present invention, and FIG. 2 is an exploded perspective view of a main part of the seatbelt retractor 100 shown in FIG. 3 is a perspective view of a main part of the locking base 5 shown in FIG.
[0017]
The seat belt retractor 100 according to the first embodiment includes a substantially cylindrical bobbin 3 around which a webbing is wound, and is rotatably supported by the retractor base 1 through the bobbin 3. The cylindrical torsion bar 2 is integrally coupled to the bobbin 3 (on the right side in FIG. 1) and is integrally coupled to the disk-shaped locking base 5 on the other end side (left side in FIG. 1). And an emergency locking means 300 for preventing the locking base 5 that is a locking member from rotating in the webbing pull-out direction in the event of a vehicle emergency.
[0018]
The retractor base 1 is obtained by press-molding a metal plate so that left and right side plates 1a and 1b rise from both sides of a back plate 1c fixed to a vehicle body, and has a substantially U-shaped cross section. A torsion bar 2 combined with the bobbin 3 is bridged rotatably at positions opposed to 1a and 1b. A known winding spring device that constantly urges the bobbin 3 in the webbing winding direction through the torsion bar 2 at one end of the torsion bar 2 inserted through the side plate 1 b of the retractor base 1. (Not shown). Further, the outer peripheral portion of the locking base 5 is opposed to the inner peripheral edge of the through hole 20 opened in the side plate 1 a of the retractor base 1.
[0019]
One end side of the torsion bar 2 has a bobbin coupling portion 2a that can be integrally rotated with the bobbin 3, and the other end side is a locking base coupling portion 2b that can be integrally rotated with the locking base 5. have. Each of these coupling portions 2a and 2b is formed in a hexagonal cross-sectional shape.
The bobbin coupling portion 2a has a hexagonal cross section, and is fitted into a hexagonal insertion hole 40a of a retainer 40 fitted in a hexagonal fitting recess 3a formed on one end side of the bobbin 3. Thus, it is coupled to the bobbin 3 so as to be rotatable together. The retainer 40 is rotatably supported by the side plate 1b via a bush 41.
[0020]
The locking base coupling portion 2b has a hexagonal cross section, and is fitted into the insertion hole 8a having a hexagonal cross section in the cylindrical boss portion 8 projecting from the end surface on the bobbin side of the locking base 5 so that the locking base 5 And are integrally coupled to each other (see FIG. 3).
A fitting recess 9 for receiving the boss portion 8 of the locking base 5 is formed at the locking base side end portion of the bobbin 3, and the torsion bar 2 is interposed via the fitting recess 9. The shaft is supported so as to be relatively rotatable.
[0021]
Further, a hollow cylindrical bearing bush 10 is fitted to the shaft support portion between the boss portion 8 and the fitting recess 9. The bearing bush 10 for improving the slidability is made of, for example, a plastic having excellent slidability such as polyoxymethylene or fluorine resin, or a metal having a hard and smooth surface such as stainless steel or a bearing metal, and the boss portion in the shaft support portion. The frictional resistance between the outer peripheral surface 8 and the inner peripheral surface of the fitting recess 9 is reduced. The bearing bush 10 is preferably lightly press-fitted and fixed to at least one of the boss 8 or the fitting recess 9.
[0022]
That is, the bearing bush 10 fitted between the boss portion 8 and the fitting recess 9 absorbs rattling between the boss portion 8 and the fitting recess 9 and prevents the generation of abnormal noise. be able to. For example, like the hollow cylindrical bearing bush 70 shown in FIG. 4, a plurality of rib protrusions 71 project from the inner peripheral surface to facilitate press-fitting to the outer peripheral surface of the boss portion 8. Can do.
[0023]
The torsion bar 2 is subjected to a rotational torque of a predetermined value or more between the coupling portions 2a and 2b, and twisting deformation occurs between the coupling portions 2a and 2b. Is an energy absorption mechanism configured to perform absorption.
In the present invention, various known configurations can be adopted as the specific configuration of the emergency lock means 300 that restrains the rotation of the locking base 5 serving as the lock member in the webbing pull-out direction in the event of a vehicle emergency. For example, in the case of the first embodiment, as shown in FIG. 2, a pole 16 having a locking tooth 16 a at the tip is pivotally supported on the support shaft 7 of the locking base 5. Further, on the outer side of the through hole 20 opened in the side plate 1a, an internal tooth ratchet 21 having engagement inner teeth 25 with which the locking teeth 16a can be engaged is provided in parallel.
[0024]
The emergency lock means 300 disposed in the sensor cover 35 engages the engaging teeth 16a of the pawl 16 with the engaging inner teeth 25 of the internal ratchet 21 in the event of a vehicle emergency, so that the locking base 5 It is configured to prevent rotation in the webbing pull-out direction.
Next, the operation of the seat belt retractor 100 of the first embodiment will be described.
[0025]
When the emergency lock means 300 is activated in the event of a vehicle emergency such as a collision, the locking base 5 coupled to the other end of the torsion bar 2 is prevented from rotating in the webbing pull-out direction. When a rotational torque exceeding a predetermined value acts on one end side of the torsion bar 2 via the bobbin 3 due to the load acting on the webbing, the torsional deformation of the torsion bar 2 starts and the impact energy is absorbed.
[0026]
During this impact energy absorbing operation, the end portion on the rocking base side of the bobbin 3 rotates relative to the torsion bar 2, but the boss portion of the rocking base 5 via the bearing bush 10 having good slidability. The bobbin 3 on which the fitting recess 9 is rotatably supported by 8 can slide smoothly. Therefore, the energy absorption load that is absorbed when the torsion bar 2 undergoes torsional deformation changes stably according to the torsion angle.
[0027]
At the end of the impact energy absorption operation (when the webbing wound around the bobbin 3 is fully fed out by the energy absorption operation), the bobbin 3 is pulled out by the load acting on the webbing (upward in FIG. 1). ) And the locking base 5 locked to the side plate 1a of the retractor base 1 via the pole 16 and the internal tooth ratchet 21. However, since the movement of the bobbin 3 on the side of the locking base on the locking base 5 is restricted with respect to the locking base 5 via the boss 8 and the bearing bush 10, the bobbin 3 is pulled out of the webbing with respect to the locking base 5. There is no deviation in the direction. Therefore, the bending force and the shearing force do not act on the torsion bar 2 due to the displacement of the bobbin 3 and the locking base 5 in the webbing pull-out direction.
[0028]
That is, the seatbelt retractor 100 according to the first embodiment does not apply a bending force and a shearing force to the torsion bar 2 torsionally deformed, and the torsion limit amount of the torsion bar 2 is set. In addition to being able to increase, it is possible to prevent the torsion bar 2 from being damaged by the excessive load acting on the webbing and the bobbin 3 from coming out of the retractor.
[0029]
FIG. 5 is a front longitudinal sectional view of an essential part of a seat belt retractor 110 according to a second embodiment of the present invention. In addition, about the component similar to the seatbelt retractor 100 which concerns on the said 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
The seat belt retractor 110 according to the second embodiment includes a substantially cylindrical bobbin 43 around which a webbing is wound, and the bobbin 43 is rotatably supported by the retractor base 41 through one end side. (Not shown) is integrally coupled with the bobbin 43, and on the other end side (left side in FIG. 5) is a cylindrical torsion bar 2 integrally coupled with a disk-shaped locking base 45; An emergency lock means 300 for preventing the locking base 45 from rotating in the webbing pull-out direction in the event of a vehicle emergency, and a stopper means 400 disposed on the opposing portion of the locking base 45 and the bobbin 43 are provided.
[0030]
The inner peripheral edge 50 of the through hole opened in the side plate 41a of the retractor base 41 is drawn into the retractor inward so as to be opposed to the outer peripheral portion 43b of the bobbin 43 at the locking base side end. ing. The outer peripheral portion 43b has a larger diameter than the outer peripheral portion 45b of the locking base 45, and extends toward the locking base along the outer peripheral surface of the outer peripheral portion 45b.
[0031]
The locking base coupling portion 2 b of the torsion bar 2 is coupled to the locking base 45 so as to be integrally rotatable by being inserted into a through hole 45 a having a hexagonal cross section of the locking base 45.
A fitting recess 49 for receiving the boss portion 48 of the locking base 45 is formed at the end of the bobbin 43 on the side of the locking base, and the torsion bar 2 is interposed via the fitting recess 49. The shaft is supported so as to be relatively rotatable.
[0032]
Further, a hollow cylindrical bearing bush 65 is fitted on the shaft support portion between the boss portion 48 and the fitting recess 49. The bearing bush 65 is made of, for example, a plastic having excellent slidability such as polyoxymethylene or fluororesin, and is crushed and compressible when a bearing load of a predetermined level or more is applied to the shaft support portion. The frictional resistance between the outer peripheral surface of the boss portion 48 and the inner peripheral surface of the fitting recess 49 in the shaft support portion is reduced. The bearing bush 65 is preferably lightly press-fitted and fixed to at least one of the boss portion 48 or the fitting recess 49.
[0033]
That is, the bearing bush 65 fitted between the boss portion 48 and the fitting recess 49 is located between the boss portion 48 and the fitting recess 49 in the same manner as the bearing bush 10 of the first embodiment. Can prevent the occurrence of abnormal noise.
The bearing bush 65 can be made of a metal having a smooth surface such as stainless steel or a bearing metal so long as it can be compressed and deformed when a bearing load exceeding a predetermined level is applied. In this case, for example, a plurality of deformed portions are appropriately provided on at least one of the inner peripheral surface or the outer peripheral surface of the metal cylindrical member so that the deformed portions are crushed when a bearing load exceeding a predetermined level is applied. It ’s fine.
[0034]
Stopper means 400 for preventing the bobbin 43 from rotating in the webbing pull-out direction when the twisting amount of the torsion bar 2 reaches a predetermined amount or more is a C-shape engraved on the bobbin side end surface of the locking base 45. A guide groove 60 which is a bottomed groove, a C-shaped guide groove 61 formed in a lock plate 54 which is press-fitted and fixed to the end surface on the locking base side of the bobbin 43 so as to face the guide groove 60, and these guides A lock piece 62 formed in a substantially bowl shape is slidable along the inner wall surfaces of the grooves 60 and 61, and the locking base 45 is within a range in which the lock piece 62 can slide relative to the guide grooves 60 and 61. And the bobbin 43 can be rotated relative to each other. The lock plate 54 is a steel plate annular member formed separately from the aluminum alloy bobbin 43.
[0035]
Next, the operation of the seat belt retractor 110 of the second embodiment will be described.
When the emergency lock means 300 is activated in the event of a vehicle emergency such as a collision, the locking base 45 coupled to the other end of the torsion bar 2 is prevented from rotating in the webbing pull-out direction. When a rotational torque exceeding a predetermined value acts on one end side of the torsion bar 2 via the bobbin 43 due to the load acting on the webbing, the torsional deformation of the torsion bar 2 starts and the impact energy is absorbed.
[0036]
During the impact energy absorbing operation, the end portion on the rocking base side of the bobbin 43 rotates relative to the torsion bar 2, but the boss portion of the rocking base 45 via the bearing bush 65 having good slidability. The bobbin 43 in which the fitting concave portion 49 is rotatably supported by 48 can slide smoothly. Therefore, the energy absorption load that is absorbed when the torsion bar 2 undergoes torsional deformation changes stably according to the torsion angle.
[0037]
When the impact energy absorbing operation is completed (that is, when the amount of twist of the torsion bar 2 reaches a predetermined amount or more and the stopper means 400 is operated), the bobbin 43 is pulled in the webbing pull-out direction by the load acting on the webbing. Upon receiving a large force (upward in FIG. 5), the locking base 45 that is locked to the side plate 41 a of the retractor base 41 via the pole 16 and the internal ratchet 21 tends to be displaced. However, since the movement of the bobbin 43 on the side of the locking base on the locking base 45 is restricted by the boss portion 48 and the bearing bush 65 in the webbing pull-out direction, the bobbin 43 is pulled out of the locking base 45 by webbing. There is no deviation in the direction. Therefore, the bending force and the shearing force do not act on the torsion bar 2 due to the displacement of the bobbin 43 and the locking base 45 in the webbing pull-out direction.
[0038]
Therefore, like the seat belt retractor 100 of the first embodiment, the torsion bar 2 inserted through the bobbin 43 is not subjected to bending force or shearing force due to the load acting on the webbing. In addition, the torsional limit amount of the torsion bar 2 can be increased, and the bobbin 43 can be prevented from coming out of the retractor due to an excessive load acting on the webbing.
[0039]
Further, in the seat belt retractor 110 of the second embodiment, the bearing bush 65 is crushed and compressively deformed when a bearing load exceeding a predetermined level is applied. Therefore, before the locking base 45 is moved in the webbing pull-out direction due to an excessive load acting on the webbing and the outer peripheral portion 45b of the locking base 45 is locked to the internal ratchet 21 or the side plate 41a, the outer periphery of the bobbin 43 The portion 43b can abut against the inner peripheral edge 50 of the retractor base 41 to restrict movement in the webbing pull-out direction. Therefore, an excessive load in the webbing pull-out direction does not act on the boss portion 48 of the locking base 45 via the bobbin 43, and the boss portion 48 only needs to have a thickness having a strength necessary for design.
[0040]
That is, since the boss portion 48 of the locking base 45 in the second embodiment does not require a large safety factor, it can be made thinner than the boss portion 8 in the first embodiment. Therefore, there is a space in the facing portion between the locking base 45 and the bobbin 43, and the stopper means 400 as described above can be arranged without difficulty.
[0041]
In the second embodiment, the inner peripheral edge 50 protrudes inward from the retractor by drawing the entire periphery of the through hole of the side plate 41 a, and the outer peripheral part 43 b of the locking base side end of the bobbin 43. However, it is also possible to provide an inner peripheral edge 50 that protrudes inward from the retractor and faces the outer peripheral portion 43b of the bobbin 43 by applying burring or semi-shear to the entire periphery of the through hole of the side plate 41a. The configuration of the stopper means is not limited to the configuration composed of the C-shaped guide grooves 60 and 61 and the lock piece 62 in the second embodiment, and various configurations can be adopted.
[0042]
Further, the seat belt retractor of the present invention is not limited to the configuration of the bobbin, the torsion bar, the bearing bush and the like in each of the above-described embodiments, and can of course take various forms. For example, the bearing bush 10 (60) in each of the above embodiments is fitted to the shaft support portion between the boss portion 8 (48) of the locking base 5 (45) and the fitting recess 9 (49) of the bobbin 3 (43). However, the bearing bush of the present invention is not limited to this.
[0043]
For example, like the bearing bush 70 of the seat belt retractor 120 according to the third embodiment of the present invention shown in FIG. 6, the outer peripheral surface of the boss portion 8 of the locking base 5 and the inner periphery of the fitting recess 59 of the bobbin 53. It can be made into the shape provided with the cylindrical part 71 interposed between the surfaces, and the flange part 72 interposed between the locking base side end surface of the bobbin 53 and the bobbin side end surface of the locking base 5. .
[0044]
In this case, since the bearing bush 70 having good slidability is interposed over the entire contact portion between the locking base 5 and the bobbin 53, the end of the bobbin 43 on the side of the locking base is a torsion bar. When the impact energy is absorbed relative to 2, the locking base side end surface of the bobbin 43 can also slide smoothly with respect to the bobbin side end surface of the locking base 5. Therefore, the energy absorption load that is absorbed when the torsion bar 2 undergoes torsional deformation can be changed more stably according to the torsion angle.
[0045]
Furthermore, in the emergency lock means in each of the above embodiments, the rotation of the lock member in the webbing pull-out direction is prevented by engaging the pole pivotally supported by the lock member with the engaged portion of the retractor. Although the present invention is configured, the present invention is not limited to this, and the locking means may be configured by providing latch teeth on the lock member and pivotally supporting the pole on the retractor.
[0046]
【The invention's effect】
According to the seat belt retractor of the present invention as described above, when the bobbin receives a large force in the webbing pull-out direction due to the load acting on the webbing, the end of the bobbin on the lock member side is the boss of the lock member and the bearing bush. Therefore, even when the bobbin receives a large force in the webbing pull-out direction due to the load acting on the webbing, the torsion rod inserted through the bobbin has bending force and shear. Force does not act.
[0047]
Furthermore, when a bearing bush that enhances slidability is fitted to the shaft support between the bobbin and the lock member, the torsion bar is twisted to cause relative rotation between the bobbin and the lock member. The energy absorption load can be stabilized by reducing the frictional resistance of the shaft support.
A bearing bush that can be compressed and deformed by a predetermined bearing load or more is fitted on a shaft support between the bobbin and the lock member, and an outer peripheral portion of the bobbin on the lock member side end of the retractor base. By facing the inner peripheral edge of the through-hole opened in the side plate, the bearing bush is compressed and deformed by a bearing load exceeding a predetermined value after the energy absorption operation is completed, and the outer peripheral portion of the bobbin abuts on the inner peripheral edge of the retractor base. Therefore, the movement in the webbing pull-out direction is restricted, so that the bobbin can be prevented from coming out of the retractor.
[0048]
Therefore, it is possible to increase the torsional limit amount of the torsion bar and to prevent the bobbin from coming out of the retractor due to the excessive load acting on the webbing and preventing the torsion bar from being pulled out. A retractor for a seat belt provided with a mechanism can be provided.
[Brief description of the drawings]
FIG. 1 is a front longitudinal sectional view of a seat belt retractor according to a first embodiment of the present invention.
2 is an exploded perspective view of a main part of the seat belt retractor shown in FIG. 1; FIG.
FIG. 3 is a perspective view of a main part of the locking base shown in FIG. 2;
4 is an overall perspective view showing a modification of the bearing bush shown in FIG. 1. FIG.
FIG. 5 is a front longitudinal sectional view of an essential part of a seat belt retractor according to a second embodiment of the present invention.
FIG. 6 is a front longitudinal sectional view of an essential part of a seat belt retractor according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Retractor base 2 Torsion rod 3 Bobbin 5 Locking base 8 Boss part 9 Fitting recessed part 10 Bearing bush 21 Internal tooth ratchet 100 Seat belt retractor 300 Emergency locking means

Claims (2)

A bobbin around which the webbing is wound, a lock member that is engaged with the retractor base to prevent rotation in the webbing withdrawal direction in the event of a vehicle emergency, and is rotatably supported by the retractor base through the bobbin. In addition, a retractor for a seat belt provided with a torsion bar integrally coupled to the bobbin on one end side and integrally coupled to the lock member on the other end side,
The other end side of the torsion bar is inserted into the lock member side end of the bobbin through a fitting recess that is recessed to receive a cylindrical boss protruding from the end surface of the lock member. A bearing bush that enhances slidability is fitted to at least the shaft support portion in the contact portion between the bobbin and the lock member .
The retractor for seatbelts characterized by the outer peripheral part of the said locking member facing the inner periphery of the through-hole opened by the side plate of the said retractor base . A bobbin around which the webbing is wound, a lock member that is engaged with the retractor base to prevent rotation in the webbing withdrawal direction in the event of a vehicle emergency, and is rotatably supported by the retractor base through the bobbin. In addition, a retractor for a seat belt provided with a torsion bar integrally coupled to the bobbin on one end side and integrally coupled to the lock member on the other end side,
The other end side of the torsion bar is inserted into the lock member side end of the bobbin through a fitting recess that is recessed to receive a cylindrical boss protruding from the end surface of the lock member. A bearing bush capable of being compressed and deformed by a bearing load of a predetermined value or more is fitted to at least the shaft support portion in the contact portion between the bobbin and the lock member.
The retractor for seatbelts characterized by the outer peripheral part of the lock member side edge part of the said bobbin facing the inner periphery of the through-hole opened by the side plate of the said retractor base.

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