JPH08253104A - Seat belt retractor - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an inexpensive and good seat belt retractor capable of easily releasing the end lock without complicating the structure of the lock operating means for operating the lock means in case of a vehicle emergency. [Structure] The poles 16 and 13 that engage with the inner teeth 2a and 2c of the side plates 1a and 1b of the retractor and can prevent the bobbin 3 from rotating in the webbing pull-out direction can move relative to the bobbin 3 by a predetermined amount. Supported. The ratchet wheel 18 normally rotates following the bobbin 3 and relatively rotates in the webbing winding direction with respect to the bobbin 3 to engage the poles 16 and 13 with the inner teeth 2a and 2c. Bobbin 3 of the poles 16 and 13
An oscillating lever member 20 is provided between the bobbin 3 and the ratchet wheel 18 so as to be able to oscillate the ratchet wheel 18 in the webbing take-up direction by a relative movement with respect to the bobbin 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat belt retractor (winding device), and more particularly to an improvement of a seat belt retractor having an emergency locking mechanism.

[0002]

2. Description of the Related Art Conventionally, in a seat belt retractor for safely holding an occupant of a vehicle in a seat, the retractor is physically locked by inertial sensing means which responds to sudden acceleration, collision or deceleration. 2. Description of the Related Art An emergency lock type retractor is provided that has an emergency lock mechanism to effectively and safely restrain an occupant and reduce a feeling of pressure caused by webbing.

An example of such an emergency lock type retractor is a deceleration sensing means (inertia sensing means) that operates in an emergency of a vehicle, such as a seat belt retractor disclosed in Japanese Patent Application Laid-Open No. 5-246303. ), The lock operating means is operated by a reel shaft (winding shaft).
The rotation of the reel shaft in the webbing pull-out direction by engaging the first and second engagement members provided at both ends of the reel shaft with the first and second engaged portions of the frame (retractor base). Some are equipped with locking means that can be used.

According to the locking means of the retractor,
Since the plurality of engaging members engage with the engaged portions formed on both side walls of the frame in synchronization with each other, the rotation of the reel shaft in the webbing pull-out direction can be reliably locked when necessary and a sufficient engagement can be achieved. A stopping force can be obtained, and the reliability of the emergency lock mechanism can be improved.

FIG. 12 illustrates the operation of the main pawl (first engaging member) 61 and the lock gear (lock actuating means) 64 in the locking means as described above. FIG. 12 (a) shows the main pawl 61 at the standby position. (b) is the main pawl 6
It is a figure which shows the time of the lock position of 1. FIG. 13 is a schematic sectional view of an essential part of the retractor. As the cam shape of the cam hole 64n of the lock gear 64 shown by the imaginary line, the main pawl 61 is completely engaged by the relative rotation of the reel shaft 63 in the α direction as shown in FIGS. 12 (a) to 12 (b). When the main pawl 61 shifts to the lock position, the main pawl 61 performs a self-locking action by the action of the teeth 62f on the frame side wall on the steep slope side. At the time of this self-locking action, the cam follower 61f moves the guide cam face 64n ₂ of the cam hole 64n. Through the lock gear 64 (in FIG. 12, cam holes 64k, 64m,
(Indicated by 64n) is set to have a cam shape that slightly rotates in the β direction in the reverse direction. In this way, the cam hole 64n
By setting the cam shape of the above, when the main pawl 61 is completely engaged with the tooth 62f, the locking claw of the lever in the deceleration detecting means (not shown) can be free from the engagement with the tooth of the lock gear. Like

That is, when the cam follower 61f shifts from the standby position shown in FIG. 12 (a) to the lock position shown in FIG. 12 (b), the acting force from the cam follower 61f is transmitted to the lock gear to wind the lock gear 64 around the webbing. The reverse rotation control means of the lock gear is constituted by the guide cam surface 64n ₂ which reversely rotates in the taking direction. Therefore, the lock operating means is provided with a reverse rotation control means for reversely rotating the lock operating means in the webbing winding direction by a predetermined amount while the main pawl 61 is performing the self-locking action. The reverse rotation brings the deceleration sensing means into a free state. Therefore, when the entire amount of the webbing is suddenly wound up according to the spring force of the take-up spring from the pulled-out state of the webbing, the impact causes the deceleration sensing means to operate, which prevents the lock gear from rotating in the webbing take-up direction. It is described that it is possible to prevent so-called end lock in which the webbing in the fully wound state cannot be pulled out or wound.

Further, the main pawl 61 provided at one end of the reel shaft 63 and the backup pawl 70 provided at the other end are synchronized with each other, and the teeth 62f and 6 of the side walls of each frame are synchronized.
In order to engage with 2 g, the reel shaft 63 is penetrated with a joint pin 69 which is an engaging member control means.
As shown in FIG. 13, a main body 69a of the joint pin 69 has a circular cross section, and an arm 69b extending at a right angle to the main body 69a is formed at the right end of the joint pin 69. A cam follower 69c having a circular cross section is provided at the tip of 69b, and the cam follower 69c is guided to the cam hole 64m of the lock gear.
A shaft portion 69d having a rectangular cross section is provided at the left end of the main body 69a in the figure.
Is formed and is fitted into a hole formed at one end of the backup pawl 70 so as not to be relatively rotatable.

Therefore, the cam follower 69c is replaced by the cam hole 64.
When the arm 69b is rotated by being guided by m, the main body 69a rotates, and the rotation of the main body 69a causes the backup pawl 7 to rotate.
0, the backup pawl 70 is transferred to the cam hole 64.
The cam follower 69c is rotated according to the movement of the cam follower 69c guided by m. Therefore, the backup pawl 70
Can be interlocked with the rotation of the main pawl 61 which rotates according to the movement of the cam follower 61f guided by the cam hole 64n of the lock gear.

[0009]

However, in the case of the seat belt retractor disclosed in Japanese Unexamined Patent Publication No. 5-246303, the reverse rotation control means of the lock gear for preventing the end lock is the cam hole 64n. Since it is constituted by the guide cam surface 64n ₂ and the cam follower 61f, and the lock operating means is caused to perform a complicated reverse rotation control operation,
A complicated cam shape is required, and dimensional accuracy and assembly accuracy of each component are strictly required.

In addition, the teeth 62 formed on the side walls of each frame
Main pawl 6 for f and tooth 62g at the same time
The joint pin 69, which is an engagement member control means for completing the engagement between the first and the backup pawls 70, includes the arm 69b, the shaft portion 69d, and the cam follower 69c as described above.
Must be provided, and there is a problem that the shape becomes complicated. Further, the joint pin 69 causes the backup pawl 70 to be interlocked with the rotation of the main pawl 61 by the torsional rotation of the main body 69a, so that an excessive pulling force acts on the webbing to generate an impact turning force. When added to the pin 69, a shocking twisting force is applied to the base portion of the arm 69b and the shaft portion 69d to which one end of the backup pawl 70 is fitted, and there is a possibility of damage.

Therefore, the lock actuating means needs to strictly control the strength of each component as well as the dimensional variation and the assembly accuracy, which causes an increase in manufacturing cost. Therefore, an object of the present invention is to solve the above-mentioned problems, and an inexpensive and good seatbelt lid for easily releasing the end lock without complicating the structure of the lock operating means for operating the locking means in case of an emergency of the vehicle. (EN) Provided is a tractor, and an inexpensive and good seat belt retractor capable of simultaneously engaging a pair of engaging members provided at both ends of a winding shaft with an engaged portion of a side wall of a retractor base. That is.

[0012]

The above object of the present invention is to provide an engaging member disposed on at least one end of a winding shaft for winding a webbing to engage with an engaged portion of a retractor base. Locking means capable of blocking the rotation of the winding shaft in the webbing withdrawing direction, and normally rotating following the winding shaft,
Lock actuating means for actuating the lock means by relatively rotating in the webbing take-up direction with respect to the take-up shaft;
A seatbelt retractor having an emergency lock mechanism, comprising: inertial sensing means that operates in an emergency of a vehicle; and locking means that prevents rotation of the lock operating means in the webbing pull-out direction by the operation of the inertial sensing means. , The engaging member is supported so as to be relatively movable with respect to the winding shaft by a predetermined amount, and the lock operating means is reversely rotated in the webbing winding direction by relative movement of the engaging member with respect to the winding shaft. A swingable swinging lever member is disposed between the winding shaft and the lock operating means, and the lock operating means is moved in the webbing winding direction after the engaging member engages with the engaged portion. This is achieved by a seat belt retractor characterized in that the lock operating means and the locking means are disengaged by reverse rotation.

Further, another object of the present invention is that the pair of engaging members disposed at both ends of the winding shaft around which the webbing is wound are engaged with the respective engaged portions of the retractor base, and the winding is performed. Locking means capable of preventing rotation of the take-up shaft in the webbing pull-out direction,
A seat belt retractor having an emergency locking mechanism, comprising: a lock actuating means for actuating the locking means by rotating relative to the take-up shaft in the webbing take-up direction in case of an emergency of the vehicle; Engaging members extend along the center axis of rotation of the winding shaft and are respectively swingable around the substantially central portion of the winding shaft on both swing ends of a control pin disposed in the winding shaft. The control pin, which is engaged and is swung by the lock operating means, is achieved by a seat belt retractor characterized in that the pair of engaging members are engaged with the engaged portion.

[0014]

According to the above construction, when the inertial sensing means is actuated by the locking means to prevent the lock actuating means from rotating in the webbing pull-out direction in the event of a vehicle emergency, the lock actuating means moves the webbing take-up direction relative to the take-up shaft. Since it rotates relative to, the locking means is activated. The engaging member of the lock means actuated by the lock actuating means moves relative to the take-up shaft rotating in the webbing draw-out direction while engaging with the engaged portion, and then the webbing draw-out of the take-up shaft. Prevent rotation in any direction. At this time, the rocking lever member rocked by the relative movement of the engaging member with respect to the winding shaft reversely rotates the lock operating means in the webbing winding direction. Therefore, the engagement of the locking means, which has prevented the rotation of the lock operating means in the webbing pull-out direction, is released.

Therefore, the engagement that prevents the webbing from being pulled out is only the engagement between the engaged portion and the engaging member,
The amount of rotation of the winding shaft required to release these engagements can be made smaller than in the state in which the locking means remains engaged with the lock operating means. According to the other configuration, the control pin is swung about the substantially central portion by the lock actuating means that is actuated in the emergency of the vehicle. Then, the pair of engaging members engaged with both swinging end portions of the control pin are swingably rotated in the direction of engaging with the respective engaged portions, and both engaging members are engaged with each other. Engage with the engaging part at the same time.

Therefore, no twisting force is applied to the control pin for simultaneously engaging both engaging members with each engaged portion when the engaging members are swung. Further, the control pin does not need an arm for rotating the other engaging member in conjunction with the engaging operation of the one engaging member with respect to the engaged portion, so that the structure can be simplified and the assembly can be performed. Will be easier.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. 1 to 3 are an exploded perspective view and a front vertical cross-sectional view of a seat belt retractor according to the present invention. The base 1 has a substantially U-shaped cross section, and opposite side plates 1a and 1b. Through holes are formed opposite to each other, and a bobbin 3, which is a winding shaft for winding the webbing, is rotatably mounted around the through hole. Further, on the inner peripheral edges of these through holes, internal teeth 2a, 2b which are engaged parts of engaging members arranged at both ends of the bobbin 3 are provided.
Are formed, and the outer periphery of the inner teeth 2a, 2b is drawn to increase the strength of the side plates 1a, 1b. A known winding spring device 15 is arranged at an end portion of the bobbin 3 on the side plate 1b side, and the bobbin 3 is constantly urged in a winding direction of the webbing.

As shown in FIG. 4, the bobbin 3 is a substantially cylindrical winding shaft integrally formed of aluminum alloy or the like, and the body 28 around which the webbing is wound has a webbing end portion. A slit opening 28a penetrating in the diametrical direction is provided for inserting and holding. In addition, as shown in FIG. 4 (c), the bobbin 3 is provided with a pin through hole 29 formed by combining conical spaces extending along the central axis of rotation and extending from the substantially central constriction to both end surfaces. Is provided,
A hemispherical pin support portion 29a is formed in the central narrowed portion of the pin through hole 29. Therefore, the round rod-shaped control pin 27 is inserted into the pin through hole 29. Control pin 27
A hemispherical engaging portion 27a having a spherical radius slightly smaller than the spherical radius of the pin supporting portion 29a is formed at the center of the pin supporting portion 29a.
The control pin 27 inserted into the pin through hole 29 from the left side opening in FIG.
It is arranged in the pin through hole 29 so as to be swingable around an engaging portion 27a that engages with 9a.

On both end faces of the bobbin 3, as shown in FIGS.
As shown in FIG. 5, the rotation supporting shafts 6 and 11 for rotatably supporting the bobbin 3 and the pawls 16 and 13 which are engaging members engageable with the inner teeth 2a and 2b can be pivotally rotated. Support shafts 7 and 12, which are pivotally supported, are provided in a protruding manner. The rotation supporting shafts 6 and 11 of the bobbins 3 are respectively provided with a gear case 34 described later.
Is rotatably supported by the shaft supporting portion 34b and the retainer 51 that serves as a winding shaft of the winding spring device 15. Further, when the pawls 16 and 13 swing and rotate in the direction of engaging the inner teeth 2a and 2b, the locking teeth 16 of the pawls 16 and 13 are rotated.
c, 13c and the rear end portions 16e, 13e of the respective poles on the opposite side are positioned, and locking teeth 16c, 1 are formed between the inner teeth 2a, 2b.
When a large load is applied to 3c, pressure receiving surfaces 5 and 4 that receive the large load are provided on both end surfaces of the bobbin 3.
Further, on the sensor side end surface of the bobbin 3 shown in FIG. 4 (b), a storage recess 10 for storing a compression coil spring 36 for urging the ratchet wheel 18 which is a lock operating means described later in the webbing pull-out direction, A locking projection 8 for restricting counterclockwise rotation of a swing lever member 20 swingably supported by a ratchet wheel 18, and an arm portion 26c of a lock arm 26 for pressing a sensor spring 25 described later. Recess 9 that is a relief to prevent interference with
Are provided.

At the center of the pole 13, there is provided a long hole 13b which is loosely fitted to the end of the control pin 27 projecting from the pin through hole 29 of the bobbin 3 on the winding spring device side. A shaft hole 13a loosely fitted to the support shaft 12 is provided between the elongated hole 13b and the pole rear end portion 13e. That is, since the shaft hole 13a is in a loosely fitted state with respect to the support shaft 12, the pole 13 is pivotally supported on the support shaft 12 so as to be capable of swinging rotation and relatively movable by a predetermined amount. Further, a tapping screw 14 is screwed to an end portion of the control pin 27 penetrating the elongated hole 13b of the pole 13 on the take-up spring device side, and a flange portion of the tapping screw 14 is a take-up spring of the bobbin 3. The pole 13 is prevented from rising from the end surface on the device side.

Further, the pole rear end portion 13e of the pole 13
An overhanging portion 13d is provided on the inner side of the overhanging portion 13d so that the pole 13 does not swing and rotate in the engagement direction with the internal teeth 2b by itself when the emergency locking mechanism is inactive.
d is in contact with the pressure receiving surface 4 (see FIG. 8). Then, when the pole 13 is rocked and rotated in the engagement direction with the internal teeth 2b during the operation of the emergency lock mechanism, the contact between the overhanging portion 13d and the pressure receiving surface 4 is released, and the pole of the pole 13 is released. The rear end portion 13e and the pressure receiving surface 4 can be rotated until they come into contact with each other.

On the other hand, a shaft hole 16a that loosely fits into the support shaft 7 is provided at the center of the pole 16 and the space between the shaft hole 16a and the pole rear end 16e is the same. An elongated hole 16b is loosely fitted to the sensor side end of the control pin 27 protruding from the pin through hole 29 of the bobbin 3. That is, since the shaft hole 16a is loosely fitted to the support shaft 7, the pole 16 is pivotally supported on the support shaft 7 so as to be swingable and rotatable and relatively movable by a predetermined amount. Further, the tip end of the support shaft 7 penetrating the shaft hole 16a of the pole 16 is caulked to the locking hole 17b of the holding plate 17 into which the through hole 17a is fitted by the rotary support shaft 6 of the bobbin 3. The holding plate 17 prevents the pole 16 from rising from the end surface of the bobbin 3.

The sensor-side end of the control pin 27 penetrating the elongated hole 16b of the pole 16 is disposed outside the holding plate 17 and is rotatably supported by the rotation support shaft 6 of the bobbin 3. The ratchet wheel 18 is inserted into a cam hole 18a formed in the ratchet wheel 18. Therefore, when the ratchet wheel 18 rotates relative to the bobbin 3 in the webbing winding direction (arrow X ₁ direction in FIG. 2), the cam hole 18a causes the end of the control pin 27 on the sensor side to move toward the bobbin 3.
As a result, the pawl 16 swings and rotates about the support shaft 7 in the engagement direction (arrow Y ₁ direction) with the internal tooth 2a.

At this time, since the control pin 27 is swingably arranged in the pin through hole 29 with the engaging portion 27a as the swing center, the end portion of the control pin 27 on the winding spring device side is arranged. , The bobbin 3 is moved in a direction away from the rotation center axis of the bobbin 3 to push the elongated hole 13b of the pawl 13, and the pawl 13 is engaged with the inner tooth 2b around the support shaft 12 (arrow Y in FIG. 1).
Swing in ₂ directions).

That is, the pair of pawls 16 and 13 engaged with both pivot ends of the control pin 27 are pivotally rotated in a direction in which they engage with the internal teeth 2a and 2b, respectively. Locking teeth 16c and 13c of 16, 13 are internal teeth 2a,
Locking means for preventing rotation of the bobbin 3 in the webbing pull-out direction by simultaneously engaging with 2b constitutes.

Therefore, the control pin 2 for simultaneously engaging the pair of pawls 16 and 13 with the internal teeth 2a and 2b, respectively.
No twisting force is applied to 7 when swinging both poles 16 and 13. In addition, the control pin 27 has two internal teeth 2
Since the arm for rotating the other pole 13 in conjunction with the engaging operation of the one pole 16 with respect to a and 2b is not required, the structure can be simplified and the assembly is easy.

By the way, an engaging member control means for synchronizing a pair of engaging members provided at both ends of the bobbin is provided with one engaging member by torsional rotation of a rod-shaped body inserted into the bobbin like a conventional joint pin. In the case of the type in which the mating member is interlocked with the other engaging member, if the through hole for inserting the joint pin has a large removal taper, the joint pin rattles in the through hole, and the engaging member is securely engaged. Since the synchronization cannot be achieved, it is impossible to increase the punching taper of the core forming the through hole. Further, if the shape of the joint pin is made to correspond to the tapered shape of the through hole to suppress the rattling, there is a problem that the processing accuracy of the joint pin itself is required and the manufacturing cost is increased.

However, according to the engaging member control means according to the present invention, the pin through hole 29 through which the control pin 27 is inserted is formed by combining the conical spaces extending from the substantially central constriction portion to both end surfaces. When the bobbin 3 is integrally molded, the core forming the pin through hole 29 has a large removal taper, which facilitates removal of the core. Also, the control pin 27
As for the shape of itself, the parts other than the engaging part 27a do not require high processing accuracy, and therefore can be manufactured at low cost.

The ratchet wheel 18 is a ratchet wheel whose center hole is rotatably supported by the rotary support shaft 6, and its outer peripheral portion is engaged with a sensor arm 43 of a vehicle body acceleration sensing means 41 described later. Ratchet teeth 18b facing the belt withdrawing direction are formed. A boss portion 18c protruding toward the outside of the retractor around the center hole of the ratchet wheel 18 is a disk-shaped inertial body for constituting a webbing acceleration sensing means which is an inertial sensing means for sensing the webbing pull-out acceleration. The center hole 30a of the inertia plate 30 is pivotally supported. A locking claw portion 23 protrudingly provided around the boss portion 18c positions the inertia plate 30 in the thrust direction. An engaging projection 31 of an inertia plate 30 is engaged with an elongated hole 24 formed in the ratchet wheel 18, and one end 24a of the elongated hole 24 rotates the inertia plate 30 when the emergency locking mechanism is not activated. Directional positioning is performed.

As shown in FIG. 6, the ratchet wheel 1
On the outer surface of 8, a shaft portion 22 that rotatably supports the lock arm 26 and a holding projection 18e that prevents the lock arm 26 from rising are provided in a protruding manner. On the inner side surface of the ratchet wheel 18, there is provided a spring receiving portion 21 for holding the other end of the compression coil spring 36 whose one end is supported by the upper wall 10a of the storage recess 10. The compression coil spring 36 is attached to the bobbin 3. On the other hand, the ratchet wheel 18 is rotationally biased in the webbing pull-out direction (arrow X ₂ direction).

The lock arm 26 has a pair of hook portions 18d provided on the outer surface of the ratchet wheel 18.
An arm portion 26c that presses the central portion in the longitudinal direction of the linear sensor spring 25 whose both ends are supported, and an engaging claw 26b that can mesh with the internal gear 34a of the gear case 34 are provided. Therefore, the lock arm 26 constitutes a locking means for preventing the ratchet wheel 18 from rotating in the webbing pull-out direction by engaging the engaging claw 26b with the internal gear 34a. The engaging claw 26b is shown in FIG.
As shown in, by the urging force of the sensor spring 25,
It is pressed and biased by the pressing protrusion 32 of the inertia plate 30. An opening is formed in the ratchet wheel 18 corresponding to the swing range of the arm portion 26c, and the arm portion 26c penetrates the opening. This indicates the engagement state of the arm portion 26c with the sensor spring 25. It is for guarantee.

Further, a swing lever member 20, which is axially supported by a shaft hole 20a, is swingably disposed on a support shaft 19 projecting from the inner surface of the ratchet wheel 18. Rotation of the swing lever member 20 in the counterclockwise direction is appropriately regulated by a locking projection 8 provided on the end surface of the bobbin 3 on the sensor side, and pressing force provided on the sensor side surface of the pole 16 is provided. The protrusion 16d is assembled between the bobbin 3 and the ratchet wheel 18 so that the rotation in the clockwise direction is appropriately regulated by the contact between the support shaft 19 and the locking protrusion 8.

A gear case 34 disposed outside the inertia plate 30 is provided with a shaft supporting portion 34b for rotatably supporting the bobbin 3 at the center thereof, and the bottom surface of the shaft supporting portion 34b is a bobbin. 3 is a positioning surface in the rotation axis direction. Further, at the lower part of the gear case 34, a box-shaped storage section 40 for storing a vehicle body acceleration sensing means 41 which is an inertial sensing means for sensing the acceleration of the vehicle body is provided. In the vehicle body acceleration sensing means 41, a ball weight 44, which is an inertial body, is placed on a sensor case 42 fixedly installed in the storage portion 40, and is engaged with the ratchet teeth 18b to pull out the webbing of the ratchet wheel 18. A sensor arm 43, which is a locking means having a locking protrusion 43a capable of blocking the rotation of, is swingably attached.

Then, the side plate 1 covering the gear case 34
A sensor cover 35 is provided outside the a. Next, the operation of the seat belt retractor will be described. First, in a normal use state, as shown in FIG. 6, the ratchet wheel 18 is moved to the bobbin 3 by the biasing force of the compression coil spring 36 mounted between the spring receiving portion 21 and the upper wall 10a of the storage recess 10. On the other hand, the control pin 27, which is biased in the webbing pull-out direction (arrow X ₂ direction) and whose end engages with the cam hole 18a, does not engage the pawls 16 and 13 with the internal teeth 2a and 2b. Biased in the direction.

That is, the pawl 16 swingably rotatable about the support shaft 7 has the locking teeth 16c by the sensor-side end of the control pin 27 located at a position away from the center axis of rotation of the bobbin 3. It is biased in a direction that does not engage with the inner teeth 2a. At this time, since the control pin 27 is swingably arranged in the pin through hole 29 with the engaging portion 27a as the swing center, the control pin 27 positioned near the rotation center axis of the bobbin 3 can be swung. The end portion on the winding spring device side urges the locking tooth 16c of the pawl 13 which is swingably rotatable about the support shaft 12 in a direction not engaging with the inner tooth 2b (see FIGS. 7 and 8). ).
Therefore, the bobbin 3 is rotatable in the webbing pull-out direction (arrow X ₂ direction) with respect to the side plates 1a and 1b, and the webbing 50 can be pulled out freely.

As shown in FIG. 6, the vehicle body acceleration sensing means 4
When the ball weight 44 of No. 1 is placed at a predetermined position of the sensor case 42, the sensor arm 4
The locking protrusion 43a of No. 3 is not engaged with the ratchet teeth 18b of the ratchet wheel 18,
Rotates following the bobbin 3. The engaging claw 26b of the lock arm 26 in the webbing acceleration sensing means is
As shown in FIG. 6, the sensor spring 25 is biased by the biasing force of the sensor spring 25 to a position that does not mesh with the internal gear 34 a of the gear case 34. The inertia plate 30 biased in the webbing pull-out direction (arrow X ₂ direction) with respect to the ratchet wheel 18 by the engaging claws 26b is shown in FIG.
Further, as shown in FIG. 6, the engagement protrusion 31 is pressed and urged by the one end 24 a of the elongated hole 24 to be positioned in the rotation direction, and rotates integrally with the bobbin 3 via the ratchet wheel 18.

When the vehicle body acceleration sensing means 41 or the webbing acceleration sensing means, which is the inertial sensing means, is actuated in an emergency such as a collision, a sensor which is a locking means for preventing the lock actuating means from rotating in the webbing pull-out direction. The arm 43 or the lock arm 26 blocks the rotation of the ratchet wheel 18 in the webbing pull-out direction to operate the locking means of the retractor.

First, the operation of the lock actuating means when the vehicle body acceleration sensing means 41 actuates the locking means of the retractor in the event of an emergency such as a collision will be described. When the vehicle receives a speed change more than a predetermined value in an emergency such as a collision, the ball weight 44 of the vehicle body acceleration sensing means 41 senses the acceleration of the vehicle body and rolls. Then, the locking protrusion 43a is engaged with the ratchet wheel 18
The sensor arm 43 swings and rotates in the direction in which it meshes with the ratchet teeth 18b. Next, when the webbing is pulled out from the retractor by the movement of the upper body of the occupant, the bobbin 3 rotates in the webbing pull-out direction (arrow X ₂ direction). At this time, the ratchet wheel 18 also rotates following the bobbin 3, but when the locking projections 43a and the ratchet teeth 18b are completely meshed as shown in FIG. 7, the ratchet wheel 18 rotates in the webbing pull-out direction at that time. Is blocked.

Further, when the webbing 50 is pulled out from the retractor, the ratchet wheel 18 causes a rotation delay with respect to the bobbin 3, and the webbing winding direction (arrow X ₁
Direction), the cam hole 18a of the ratchet wheel 18 moves the sensor-side end of the control pin 27 toward the rotation center axis of the bobbin 3. Therefore, the pole 16 is pivotally rotated about the support shaft 7 in the engagement direction with the internal teeth 2a (direction of arrow Y ₁ ). At this time, control pin 2
7 is swingably arranged around the engaging portion 27a in the pin through hole 29, so that the end portion of the control pin 27 on the winding spring device side is away from the rotation center axis of the bobbin 3. Move away and push the oblong hole 13b of the pole 13 away,
The engagement direction (arrow Y ₂ direction) of about the pivot shaft 12 and the inner teeth 2b the pole 13 to the rocking rotation. That is, both ends of the control pin 27 move in opposite directions with the engaging portion 27a as the swing center.

Further, when the webbing 50 is pulled out from the retractor, as shown in FIG.
Locking teeth 16c and 13c of 6, 13 are internal teeth 2a,
The meshing with 2b is completed at the same time. In this state, the pole rear end portions 16e and 13e of the poles 16 and 13 are
There is a gap between the bobbin 3 and the pressure receiving surfaces 5, 4 of the bobbin 3, and the swing lever member 20 has the locking projection 8 of the bobbin 3 and the pole 1.
Rotation is regulated by the pressing projections 16d of 6 with almost no play.

Here, the shaft holes 16a of the poles 16 and 13,
13a is loosely fitted to the support shafts 7 and 12 of the bobbin 3 and is pivotally supported on the bobbin 3 so as to be swingable and movable by a predetermined amount.
When the webbing 50 is pulled out from the retractor, the pawls 16 and 13 rotate relative to the bobbin 3 about the rotation center axis of the bobbin 3 until the rear end portions 16e and 13e of the pawls come into contact with the pressure receiving surfaces 5 and 4.

At this time, although the pressing projection 16d of the pole 16 is in a positional relationship which is immovable with respect to the side plate 1a, the locking projection 8 of the bobbin 3 rotates in the webbing pull-out direction (arrow X ₂ direction). Due to this movement, the swing lever member 20 is
The rocking end portion is pushed by the locking projection 8 with the contact point with the pressing projection 16d as a fulcrum, and is rocked and rotated clockwise in FIG. When the oscillating lever member 20 oscillates and rotates in the clockwise direction in FIG. 9 around the contact point with the pressing protrusion 16d as the center of rotation, the support shaft 19 of the ratchet wheel 18 is rotated.
The shaft hole 20a pivotally supported on the shaft rotates in the webbing winding direction (arrow X ₁ direction) with respect to the rotation center axis of the bobbin 3. As a result, the ratchet wheel 18 is reversely rotated with respect to the bobbin 3 in the webbing winding direction (arrow X ₁ direction).

Therefore, as shown in FIG. 10, the locking protrusion 4 of the sensor arm 43 in the vehicle body acceleration sensing means 41.
3a and ratchet teeth 18b of ratchet wheel 18
There is a gap in the meshing with. That is, even in the locked state in which the locking means of the retractor prevents the bobbin 3 from rotating in the webbing pull-out direction, the engagement protrusion 43a of the sensor arm 43 in the vehicle body acceleration sensing means 41 is engaged with the ratchet teeth 18b of the ratchet wheel 18. It can be set to a releasable free state.

When the vehicle is stopped and the tension applied to the webbing 50 is released, the ratchet wheel 18 in which the engagement between the locking protrusion 43a and the ratchet teeth 18b has already been released is the compression coil spring 36. Since it is rotated in the arrow X ₂ direction with respect to the bobbin 3 by the urging force, the cam hole 18a of the ratchet wheel 18 moves the sensor side end of the control pin 27 in the direction away from the rotation center axis of the bobbin 3. To go. At this time, webbing 5
The tension in the pull-out direction that acts on 0 is released as described above, and the bobbin 3 moves in the webbing winding direction (arrow X ₁ direction).
Since it can be rotated to the
When the bobbin 3 rotates in the direction of the arrow X ₁ until the tips of the teeth 3c do not interfere with the tips of the inner teeth 2a and 2b, the pawls 16 and 13 release the engagement with the inner teeth 2a and the inner teeth 2b, respectively. Then, the bobbin 3 is unlocked by swinging and rotating about the support shafts 7 and 12, and the webbing can be freely pulled out.

Next, in an emergency such as a collision, the webbing is pulled out at a withdrawing speed higher than a predetermined value, and the operation of the lock actuating means when the locking means of the retractor is actuated by the webbing acceleration sensing means will be described with reference to FIGS. Will be described. When the upper body of the occupant moves in an emergency such as a collision, tension is applied to the webbing 50, and the bobbin 3 has a shocking webbing pull-out direction (arrow X ₂ direction) more than a predetermined value.
When the rotational force of 1 is applied, the inertia plate 30 is relatively rotationally displaced in the opposite direction (arrow X ₁ direction) to the rotation of the ratchet wheel 18 in the arrow X ₂ direction by inertia.
Then, the pressing projection 32 of the inertia plate 30 rotates the lock arm 26 around the shaft portion 22 in the clockwise direction in FIG. 11 against the urging force of the sensor spring 25. Internal tooth gear 34
The lock arm 26 swings and rotates in the direction in which it engages with a. Next, when the upper body of the occupant further moves and the webbing is pulled out from the retractor, the bobbin 3 rotates in the webbing pull-out direction (arrow X ₂ direction). This time,
Although the ratchet wheel 18 also rotates following the bobbin 3, as shown in FIG. 11, the engaging claw 26b and the internal gear 34a are rotated.
When and are completely meshed with each other, the ratchet wheel 18 is prevented from rotating in the webbing pull-out direction at that time.

Further, when the webbing 50 is pulled out from the retractor, the ratchet wheel 18 causes a rotation delay with respect to the bobbin 3, and the webbing winding direction (arrow X ₁
Direction), the cam hole 18a of the ratchet wheel 18 moves the sensor-side end of the control pin 27 toward the rotation center axis of the bobbin 3. Therefore, the pole 16 is pivotally rotated about the support shaft 7 in the engagement direction with the internal teeth 2a (direction of arrow Y ₁ ). At this time, control pin 2
7 is swingably arranged around the engaging portion 27a in the pin through hole 29, so that the end portion of the control pin 27 on the winding spring device side is away from the rotation center axis of the bobbin 3. Move away and push the oblong hole 13b of the pole 13 away,
The engagement direction about the pivot shaft 12 and the inner teeth 2b the pole 13 (arrow in FIG. 8 Y ₂ direction) to the swinging rotation. That is,
Both ends of the control pin 27 move in opposite directions with the engaging portion 27a as the swing center.

Therefore, hereinafter, the ratchet wheel 1 when operated by the vehicle body acceleration sensing means 41 described above.
Similar to the operation of 8, the locking means is operated to prevent the bobbin 3 from rotating in the webbing withdrawing direction, and the ratchet wheel 18 is rotated in the webbing winding direction (arrow X ₁ direction) with respect to the bobbin 3 in the reverse direction. . Therefore, there is a gap between the engagement claw 26b of the lock arm 26 and the internal gear 34a of the gear case 34 in the webbing acceleration sensing means. In the lock arm 26, the engaging claw 26b is driven by the urging force of the sensor spring 25 so that the internal gear 34
Since the lock arm 26 is urged to rotate in a direction that does not mesh with a (counterclockwise direction in FIG. 11), the lock arm 26 rotates in a direction in which the engagement claw 26b and the internal gear 34a disengage. Become. That is, even in the locked state in which the locking means of the retractor prevents the bobbin 3 from rotating in the webbing pull-out direction, the engagement claw 26b of the lock arm 26 in the webbing acceleration sensing means is locked to the internal gear 34a of the gear case 34.
It is possible to set the free state in which the engagement with and is released.

Then, when the tension applied to the webbing 50 is released, the ratchet wheel 18 in which the engagement between the engaging engagement claw 26b and the internal gear 34a is already released is driven by the urging force of the compression coil spring 36. Bobbin 3
Because it is rotated in the direction of arrow X ₂ against the cam hole 18a of the ratchet wheel 18 is going to move the end of the sensor-side of the control pin 27 in a direction away from the axis of rotation of the bobbin 3. Therefore, the vehicle body acceleration sensing means 41 described above
Same as the lock release by Paul 16 and Paul 13
Are oscillated and rotated in a direction to release the engagement with the inner teeth 2a and the inner teeth 2b, respectively, and the bobbin 3 is unlocked so that the webbing can be pulled out freely.

Further, the vehicle body acceleration sensing means 41 is caused by the impact of the webbing 50 being completely wound up suddenly in accordance with the spring force of the winding spring device 15 from the pulled-out state of the webbing.
Alternatively, the webbing acceleration sensing means is activated and the bobbin 3
Even when the rotation of the webbing in the pulling direction is locked and the end lock state in which the pulling up and winding are impossible is performed, the locking force between the poles 16 and 13 and the inner teeth 2a and 2b is
Only the meshing with each other is required, and the rotation amount of the bobbin 3 required to release these engagements is only required to rewind a small amount of one tooth or less of the inner teeth 2a and 2b. This small amount of rewind is
The webbing 50 wound in layers in the end lock state is forcibly pulled out so as to be wound, and the webbing 50 forcibly pulled out is rewound. When a small amount is rewound in this way, the ratchet wheel 18 does not act against the biasing force of the compression coil spring 36 that biases the ratchet wheel 18 against the bobbin 3 in the arrow X ₂ direction. The lock can be released by being urged in the arrow X ₂ direction by the urging force of the compression coil spring 36.

Therefore, in the seat belt retractor, the reverse rotation control means of the ratchet wheel 18 for facilitating the release of the end lock is supported by the pole 16 which is supported by the bobbin 3 so as to be movable relative to the bobbin 3 by a predetermined amount. And a swing lever member 20 swingably disposed between the bobbin 3 and the ratchet wheel 18 in order to reversely rotate the ratchet wheel 18 in the webbing winding direction by the relative movement of the pawl 16 with respect to the bobbin 3. Since the ratchet wheel 18 and the swing lever 20 do not require a complicated cam shape, dimensional accuracy and assembly accuracy of each component are not strictly required.

In the seat belt retractor of the above embodiment, the pair of poles 16 and 13 arranged at both ends of the bobbin 3 around which the webbing 50 is wound are provided on the inner teeth 2a and 2b of the retractor base. The lock means for engaging and blocking the rotation of the bobbin 3 in the webbing pull-out direction has been described, but the reverse rotation control means of the lock actuating means in the present invention does not necessarily require a pair of engaging members. It is also effective for a seat belt retractor in which an engaging member is provided at least at one end of the winding shaft.

The inertial sensing means, the lock actuating means, the rocking lever member, the locking means and the like in the present invention are not limited to the shapes of the above-mentioned embodiment, and it goes without saying that various modifications can be made. is there. For example, the inertial sensing means that operates in an emergency of the vehicle may be a seat belt retractor including only one of the vehicle body acceleration sensing means and the webbing acceleration sensing means, and the structure thereof can be appropriately changed.

[0053]

That is, according to the present invention, an inexpensive and good seat belt for which the end lock can be easily released without complicating the structure of the lock operating means for operating the lock means in case of an emergency of the vehicle. An inexpensive and good seat belt retractor that can provide a retractor and a pair of engaging members provided at both ends of a winding shaft to be simultaneously engaged with an engaged portion of a side wall of the retractor base. it can.

[Brief description of drawings]

FIG. 1 is a part of an exploded perspective view of a seat belt retractor according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a remaining portion of the seat belt retractor shown in FIG.

FIG. 3 is a vertical sectional front view of a seat belt retractor according to an embodiment of the present invention.

4 (a) and 4 (b) are side views of both ends of the bobbin shown in FIG. 1, and FIG. 4 (c) is a sectional view taken along the line AA of the bobbin in FIG. 4 (b).

FIG. 5 is a seat belt retractor C shown in FIG.
It is a C cross section arrow line view.

6 is a seat belt retractor D shown in FIG.
It is a D cross-section arrow line view.

7 (a) is an enlarged view of a main part of a sensor for explaining a webbing pullout lock operation operated by the vehicle body acceleration sensing means of the seat belt retractor shown in FIG. 3, and FIG. EE showing the state of the control pin at that time
It is a sectional arrow view.

FIG. 8 is an enlarged view of a main portion of the seat belt retractor shown in FIG. 7 on the winding spring device side.

9 (a) and 9 (b) are views of a winding spring device side and a sensor side for explaining a webbing pullout locking operation which is operated by a vehicle body acceleration sensing means of the seat belt retractor shown in FIG. It is a partial enlarged view, and (c) is a FF sectional arrow view figure which shows the state of the control pin at that time.

10 (a) and 10 (b) are views of a winding spring device side and a sensor side for explaining a webbing pullout lock operation which is operated by the vehicle body acceleration sensing means of the seat belt retractor shown in FIG. It is a part enlarged view, (c) is a GG cross-section arrow view which shows the state of the control pin at that time.

FIG. 11 is an enlarged view of a main part on the sensor side for explaining a webbing pullout lock operation which is operated by the webbing acceleration sensing means of the seat belt retractor shown in FIG. 3;

FIG. 12 is a view for explaining the operation of the main pawl and the lock gear in the conventional locking means, and FIG. 12 (a) is an enlarged view of an essential part showing the main pawl in the standby position and (b) in the main pawl in the locked position. .

FIG. 13 is a schematic sectional view of a main part of a conventional seat belt retractor.

[Symbols in the figure]

 1 base 1a side plate 1b side plate 2a inner tooth 2b inner tooth 3 bobbin 4 pressure receiving surface 5 pressure receiving surface 6 rotation support shaft 7 support shaft 8 locking protrusion 11 rotation support shaft 12 support shaft 13 pole 15 winding spring device 16 pole 16d pressing protrusion 18 Ratchet Wheel 19 Spindle 20 Swing Lever Member 25 Sensor Spring 26 Lock Arm 27 Control Pin 27a Engagement Part 29 Pin Through Port 29a Pin Support Part 30 Inertia Plate 34 Gear Case 34a Internal Gear 35 Sensor Cover

Claims (2)

[Claims] 1. An engaging member disposed at at least one end of a take-up shaft for winding a webbing engages with an engaged portion of a retractor base to prevent the take-up shaft from rotating in a webbing pull-out direction. Possible locking means, a lock operating means that normally rotates following the winding shaft, and operates the locking means by relatively rotating in the webbing winding direction with respect to the winding shaft; A seatbelt retractor having an emergency locking mechanism, comprising: an inertial sensing means that operates; and a locking means that prevents rotation of the lock actuating means in the webbing pull-out direction by the operation of the inertial sensing means. The coupling member is supported so as to be movable relative to the winding shaft by a predetermined amount, and the lock operating means is reversely rotated in the webbing winding direction by the relative movement of the engaging member with respect to the winding shaft. An oscillating lever member capable of oscillating as much as possible is provided between the winding shaft and the lock operating means, and the lock operating means is webbing wound after the engaging member engages with the engaged portion. A retractor for a seat belt, which is reversely rotated in a take-out direction to release the engagement between the lock operating means and the locking means. 2. A pair of engaging members disposed at both ends of a take-up shaft for winding the webbing engage with respective engaged parts of the retractor base to rotate the take-up shaft in a webbing pull-out direction. Of the seatbelt having an emergency lock mechanism including lock means capable of preventing the lock and lock operating means for operating the lock means by relatively rotating in the webbing winding direction with respect to the winding shaft in an emergency of the vehicle. A tractor, wherein a pair of the engaging members extend along the rotation center axis of the winding shaft and are swingably disposed in the winding shaft about a substantially central portion thereof as a swing center. For the seat belt, wherein the control pin, which is engaged with both swinging end portions of the pair, is swung by the lock operating means to engage the pair of engaging members with the engaged portion. Retractor.