JPH0240531B2 - ANZENBERUTONORITORAKUTA - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a retractor for safety belts used in vehicles and the like.

[Technical background of the invention and its problems]

Since this type of safety belt retractor is installed in a limited location within the vehicle, it is required to be as small as possible, and even if it is miniaturized, it can perform the locking operation reliably and be trouble-free. is desired. In particular, when the driver or tower occupant fastens the safety belt, the safety belt can be freely pulled out or inserted according to the movement of the tower occupant, for example in the range of vehicle acceleration of 0.3G or less. During abnormal changes in vehicle speed, such as sudden braking, collisions, and steep inclinations, safety belts are
When a sudden load with an acceleration of 0.3G or more is applied,
The safety belt must be locked quickly to prevent the webbing of the safety belt from being pulled out to ensure the safety of the occupants.

In addition, in conventional safety belt retractors, when the safety belt webbing is retracted, there is a risk that the webbing sensor device may accidentally lock the locking device. There were problems such as difficulty in withdrawing money.

[Purpose of the invention]

In consideration of the above-mentioned points, this invention detects the withdrawal speed of the safety belt, and when the speed fluctuation exceeds a certain level, reliably prevents the webbing of the safety belt from being withdrawn, thereby effectively ensuring the safety of tower occupants. A first object of the present invention is to provide a small and economical safety belt retractor as described above.

A second object of the present invention is to provide a lock-up stop mechanism to prevent the lock device from operating when the safety belt is retracted, thereby making it possible to smoothly and smoothly pull out the safety belt again. To provide a safety belt retractor.

[Summary of the invention]

In order to achieve the above-mentioned first object, the safety belt retractor according to the present invention includes a take-up reel in which a shaft is rotatably supported between both side plates of a retractor body, and the webbing of the safety belt is wound around the shaft. is attached, and the take-up reel is biased by a spring in the unwinding direction, and a locking device is attached to one side of the shaft to restrict rotation of the shaft, and this locking device is operated in accordance with the speed at which the webbing is pulled out. In a safety belt retractor equipped with a webbing sensor device, the webbing sensor device includes a lightweight disc-shaped latch frame that is loosely fitted to one side protrusion of a shaft that protrudes from a side plate of the retractor main body, and a latch frame that is connected to the latch frame. The sensor includes a disk-shaped sensor flywheel that is loosely fitted to the shaft on the outside, and a swingable flat sensor arm that is shaft-mounted from the outside in the mounting hole of the latch frame and is located inside the sensor flywheel. The sensor arm is curved so as to bypass the shaft portion, and an engagement piece is formed at one free end of the sensor arm so as to engage with the engagement hole of the sensor flywheel. , the other free end is formed with a lock portion that can engage with fixed internal teeth formed on the inner circumferential wall of the sensor housing, while the sensor arm is in a retracted position where the lock portion does not engage with the fixed internal teeth. A sensor flywheel, which is constantly biased by a rod spring and senses the pulling force when the webbing is suddenly pulled out, swings the sensor arm against the spring force and locks the locking portion against the fixed internal teeth. This causes the latch frame to lock the locking device.

In order to achieve the above-mentioned second object, the safety belt retractor of the present invention has a shaft rotatably supported between both side plates of the retractor body, and a take-up reel in which the safety belt webbing is wound around the shaft. and a spring biasing the take-up reel in the unwinding direction, and a lock device is installed on one side of the shaft to restrict rotation of the shaft,
In a safety belt retractor equipped with a webbing sensor device that locks the locking device in accordance with the webbing withdrawal speed, the webbing sensor device is loosely fitted into a protruding portion on one side of a shaft protruding from a side plate of the retractor main body. a disc-shaped latch frame, a disc-shaped sensor flywheel of a lightweight structure loosely fitted to the shaft on the outside of the latch frame, and a disc-shaped sensor flywheel of a lightweight structure that is shaft-mounted from the outside in a mounting hole of the latch frame and inside the sensor flywheel. and a swingable flat sensor arm located at the shaft portion, the sensor arm being curved so as to bypass the shaft portion, and having one free end thereof engaged with the engagement hole of the sensor flywheel. An engaging piece is formed that stands up as shown in FIG. is biased by a spring member to a retracted position in which the lock portion does not engage with the fixed internal teeth, and a lock-up stop mechanism is mounted on the latch frame in a dead space between the latch frame and the sensor flywheel. The lock-up stop mechanism is designed to prevent the stop portion of the sensor arm from engaging with the fixed internal teeth when the webbing is retracted.

[Embodiments of the invention]

Embodiments of the invention will be described with reference to the accompanying drawings.

In FIGS. 1 to 3, reference numeral 10 indicates a retractor for a safety belt for a vehicle or the like according to the present invention, and this retractor is attached to a limited predetermined location within the vehicle. The retractor 10 has a retractor body 11 having a U-shaped cross section. Side windows are formed in both side plates of the retractor body 11, and a shaft 15 is rotatably supported by the side windows via bearings 13, 14 (FIG. 1). Shaft 15
The axial movement of is restricted by a removably mounted stop ring 16.

A take-up reel 17 is firmly mounted on the shaft 15, and one end of the webbing (not shown) of a safety belt is fixed to and wound around the take-up reel 17. The shaft 15 protrudes through both side plates 11A and 11B of the retractor body 11, and a locking device 18 is attached to the protrusion on one side and a spiral spring 19 is attached to the protrusion on the other side.
are provided respectively. The spiral spring 19 is housed in the spring cover 20, and the take-up reel 17 is always biased in a direction to wind up the webbing.

On the other hand, the locking device 18
a ratchet wheel 23 (see FIG. 4) having a lock tooth 21 formed to protrude outward at a predetermined pitch on the side plate 11B of the rotor, and a ratchet tooth 22 facing inside the lock tooth 21;
It is arranged on the outside of this ratchet wheel 23,
Latch ring 25 having latch teeth 24 engageable with the lock teeth 21 and ratchet teeth 22
(See FIGS. 5A and 5B) is interposed between the latch ring 25 and the latch wheel 23 to keep the latch ring 25 in a floating state (the latch teeth 24 do not engage with the lock teeth 21 and the ratchet teeth 22). Supporting latch spring 26 (see Figure 6)
and has. The ratchet wheel 23 is rigidly mounted on the shaft 15 and rotates integrally with the shaft 15.

The latch spring 26 has a plurality of engaging pieces 27 that can engage with the pitch grooves between the ratchet teeth 22 of the latch wheel 23, and these engaging pieces 27 allow the latch spring 26 to move together with the latch wheel 23 in the assembled state. It is supposed to rotate. Also,
The latch teeth 24 of the latch ring 25 are curved so as to extend from the ring body toward the latch wheel 23, and then the tips of the teeth are cut and raised so as to face outward in the radial direction. A plurality of engaging pieces 29, three in the illustrated example, are formed between the latch teeth 24 and extending radially outward. This engagement piece 29 is configured to be able to engage with an opposing notch taper portion 32 of a latch frame 31 of a webbing sensor device 30, which will be described later.

The webbing sensor device 30 is arranged outside the locking device 18 and housed within the sensor housing 33. The sensor housing 33 is made of a resin material such as plastic or a metal material, and is fixed to the side plate 11B of the retractor body 11 from the outside.
Fixed internal teeth 34 are integrally molded in the circumferential direction at predetermined positions on the inner peripheral wall of the sensor housing 33 at predetermined pitch intervals, and the latch frame 31 of the webbing sensor device 30 is provided to face the internal teeth 34. The latch frame 31 has a disk shape as shown in FIGS. 2, 3, and 7A and 7B, and this latch frame 31
It is loosely fitted into.

The latch frame 31 is made of a lightweight material such as a synthetic resin material and has a lightweight structure, and its peripheral edge is bent toward the latch ring 25, and the bent portion is formed into a cylindrical shape. There are a plurality of cylindrical bent portions in the circumferential direction, for example, three.
Notches 32 are formed. A tapered portion is formed in this cutout portion 32, and this tapered portion is inclined obliquely toward the latch ring side, and the inclined piece 29 of the latch ring 25 is engaged with this cutout taper portion 32. The engagement piece 29 is always engaged with the notch taper part 32 at its deep part by the spring force of the latch spring 26, and in this engaged state, the latch ring 2
5 is supported in a floating state, the latch teeth 24 are maintained free from the lock teeth 21 and the ratchet teeth 22, and the take-up reel 17 is adapted to rotate freely.

Further, a latch sensor flywheel 35 having a large inertia is provided on the outside of the latch frame 31. This sensor flywheel 35 is also loosely fitted to the shaft 15 so as to be freely rotatable. In this case, the support part of the shaft 15 that supports the sensor flywheel 35 is connected to the shaft 1 that supports the latch frame 31.
The diameter is smaller than the part 5.

The sensor flywheel 35 is held down from the outside by a stop pin 36 to prevent it from coming off. The sensor flywheel 35 is a disc plate 37 made of resin such as plastic shown in FIGS. They are formed at equal intervals in the direction. Ratchet teeth 40 are formed on the outer periphery of the disc plate 37, and these ratchet teeth 40 are connected to a peak sensor device 41 which will be described later.
The lock lever 42 can be engaged with the lock lever 42 of the lock lever 42 of

On the other hand, a sensor arm 44 is swingably mounted on the outside of the latch frame 31 of the webbing sensor device 30. The sensor arm 44 is molded from a resin material such as 6-6 nylon containing glass fiber,
A protruding pin portion 45 is integrally molded at the center. This pin portion 45 is mounted in one mounting hole 46 of the latch frame 31 (see FIG. 7A). An engagement piece 47 is integrally molded on one free end of the sensor arm 44 . The engagement piece 47 rises outward from the blade surface of the sensor arm 44 and extends into one engagement hole 39 of the sensor flywheel 35 . On the other hand, the sensor arm 44 is curved so as to bypass the shaft 15, and a lock portion 48 is formed at the other free end. This locking portion 48 is configured to be able to engage with the fixed internal teeth 34 of the sensor housing 33, and is normally biased by the spring force of a spring member such as a bar spring 49 toward a retracted position where it does not engage with the fixed internal teeth 34. be done. At the retracted position, the engaging protrusion 50 of the sensor arm 44 engages with the stop pin 51, whereby the sensor arm 44 is locked. The sensor arm 44 extends from the protruding pin portion 45 to the engaging piece 47 and the lock portion 48.
By appropriately selecting the distance to the lever, the lever ratio can be selected, and the amount of displacement transmitted to the engagement piece 47 can be increased and transmitted to the lock portion 48. The retaining pin 51 is implanted in the latch frame 31. Both ends of the rod spring 49 are held by spring supports 52, and the center portion is held by the sensor arm 44.
The protrusion 53 is engaged with the cut-out protrusion 53, and the protrusion 53 is biased counterclockwise in FIG. The spring support 52 is attached to the periphery of the latch frame 31, and the swing of the bar spring 49 is controlled by the sensor arm 44.
is guided by a guide groove 55.

When the sensor arm 44 is in the retracted position, its lock portion 48 is positioned substantially on the outer circumferential surface of the latch frame 31. Therefore, the lock portion 48 is inserted into the notch opening 56 of the latch frame 31.
It is curved so as to enter the latch frame 31 from above.

The latch frame 31 is also provided with a lock-up stop mechanism 58. The lock-up stop mechanism 58 has a lock-up prevention member 59, as shown in FIGS. Ru. The lock-up prevention member 59 has a protruding pin 6.
0 is integrally molded, and this protruding pin 60 is pivotally mounted in a mounting hole 61 of the latch frame 31. The lock-up prevention member 59 is made of a resin material such as plastic or a metal material, and has a contact engagement portion 63 and a sensor arm 44 that can press into contact with the inner circumferential wall surface 62 of the sensor housing 33 (see FIGS. 1 and 2). It has an engaging protrusion 50 and an engageable locking protrusion 64. A U-shaped curved part 65 is formed in the middle part between the contact engagement part 63 and the protruding pin (shafting part) 60 so as to protrude to both sides, and this curved part 65 constitutes a spring part, and The engaging portion 63 is pressed against the wall surface of the sensor housing 33.

Incidentally, the amount of rocking of the lockup prevention member 59 is regulated by a pair of stopper pins 66 and 67. The stopper pins 66, 67 are implanted on the outside of the latch frame 31, as shown in FIG. 7A. This latch frame 31 has an adjustment pin 6.
8 is installed to adjust the distance between the latch frame 31 and the latch sensor flywheel 35, and to ensure the operation of the lockup prevention mechanism 58.
The adjustment pin 68 is adjusted to the same height as the engaging member 70 and is formed slightly higher than the stopper pins 51, 66, 67.

Therefore, the lock-up stop mechanism 58 prevents the webbing sensor device 3 from rewinding the safety belt.
Lock-up is prevented so that the lock device 18 is not activated and locked by the safety belt webbing, and the webbing of the safety belt is smoothly re-drawn. Specifically, when the webbing of the safety belt is unwound, the webbing is unwound vigorously by the spring action of the spiral spring 19, and this unwinding action causes the webbing sensor device 30 to be unwound.
The latch frame 31 rotates clockwise. Following the rotation of the latch frame 31, the sensor arm 44 and lockup prevention member 59 also rotate. Therefore, the contact engagement portion 63 of the lockup prevention member 59 comes into frictional contact with the smooth inner circumferential wall surface 62 of the sensor housing 33, and is moved toward the stopper pin 67 by the frictional force. As a result, the locking protrusion 64 of the lock-up prevention member 59 is connected to the engaging protrusion (step) 50 of the sensor arm 44.
This sensor arm 44 is engaged with the protruding pin 45.
The sensor arm 44 is rotated counterclockwise.
The lock portion 48 is held in the retracted position. Therefore, it is possible to reliably prevent the locking portion 48 from engaging with the fixed internal teeth 34 of the sensor housing 33, thereby regulating the locking operation of the locking device 18. Therefore, the webbing of the safety belt can be smoothly pulled out again.

When the webbing is pulled out, the lock-up prevention member 59 of the lock-up stop mechanism 58 has a contact engagement portion 63 that comes into frictional contact with the smooth inner circumferential wall surface 62 of the sensor housing 33, so that the lock-up prevention member 59 is moved toward the stopper pin 66 side. The locking protrusion 64 is disengaged from the engagement protrusion 50 of the sensor arm 44, and the sensor arm 44 is held by the spring force of the bar spring 49.

Further, two engaging pieces 70 are implanted on the outside of the latch frame 31 of the webbing sensor device 30. The engaging pieces 70 respectively engage with the engaging holes 39 of the ratchet sensor flywheel 35.
Sensor flywheel 35 and latch frame 31
are designed to rotate almost integrally.

A vehicle sensor device 41 is provided below the lock device 18 and webbing sensor device 30, as shown in FIGS. 1 and 2. The vehicle sensor device 41 is housed in a sensor box 73 and has an inertial sensing mechanism 74 and a pick-up link mechanism 75. The inertial sensing mechanism 74 has a sensor weight 76 that is swingably housed within the sensor box 73. The upper part of the sensor weight 76 is tapered into an inverted conical shape, and the sensing lever 77 of the pick-up link mechanism 75 is attached to this inverted conical part.
is engaged. This sensing lever 77
As shown in the figure, the base of the sensor box 73 is swingably supported by a cantilever. A downwardly extending sensor portion 78 is formed in the intermediate portion of the sensing lever 77, and this sensor portion 78 engages with the inverted conical portion of the sensor weight 76, and its free end engages with the lock arm 42. . The lock arm 42 is also swingably supported in the sensor box 73 in the form of a cantilever, and a lock claw 79 is integrally formed at its free end. Opposed to the ratchet teeth 40 of the sensor flywheel 35 of the device 30.

If the sensor weight 76 of the vehicle sensor device 41 senses the acceleration force and deceleration force of the vehicle and tilts more than a certain level, in FIG.
The sensing lever 77 is rotated counterclockwise, and the lock lever 42 is rotated clockwise. Due to this rotation, the lock pawl 79 of the lock lever 42 locks into the side hole 8.
0 and engages one of the ratchet teeth 40 of the sensor flywheel 35.

This engagement restricts the rotation of the sensor flywheel 35, activates the lock device 18 via the webbing sensor device 30, and prevents the webbing from being pulled out. In this case, the pick-up link mechanism 75 can convert a small amount of movement due to the inclination of the sensor weight 76 into a large amount of movement of the lock pawl 79 of the lock lever 42 by appropriately setting the lever ratio of both levers 77 and 42.

Next, the operation of this invention will be described.

When the webbing is pulled out at a low speed below a predetermined speed from the safety belt retractor 10 attached to a predetermined position on a vehicle, the latch frame 31 of the webbing sensor device 30 and the sensor flywheel 35 rotate at approximately the same speed. Therefore, the webbing sensor device 30 does not operate and the locking device 18
takes an unlocked, released state.

On the other hand, if the webbing pulling speed of the safety belt suddenly changes greatly, the latch frame 31 loosely fitted to the shaft 15 and the sensor flywheel 35
A difference in rotational speed occurs between the two due to the amount of inertia between them, and the sensor flywheel 35, which has a large inertia, cannot follow sudden speed fluctuations, and the sensor arm 44
The engaging piece 47 is relatively moved clockwise in FIG. Due to this movement, the sensor arm 44
swings around the protruding pin 45 against the spring force of the bar spring 49, and the lock portion 48 protrudes from the notch opening 56 of the latch frame 31, and the sensor housing 3
It engages with the fixed internal teeth 34 of No. 3. This engagement restricts the rotation of the latch frame 31.

By the way, even if the rotation of the latch frame 31 is restricted, the latch wheel 2 of the locking device 18
3 continues to rotate, the latch spring 26 and latch ring 25 rotate. This latch ring 2
5, the engagement piece 29 of the latch ring 25
slides within the notched tapered portion 32 of the latch frame 31. As a result of this sliding, the latch ring 25 is pushed toward the ratchet wheel 23 against the spring force of the latch spring 26, and the latch teeth 24 are moved between the lock teeth of the retractor body 11 and the ratchet teeth 22 of the ratchet wheel 23. interposed between the lock teeth 21 and the ratchet teeth 22,
Rotation of the ratchet wheel 23 is restricted. This restricts the rotation of the shaft 15 and the take-up reel 17, and the take-up reel 17 is locked.

In addition, when the vehicle speed changes rapidly due to a collision or sudden acceleration, the inertial sensing mechanism 7 of the peak sensor device 41 detects this fluctuation state.
4 senses. When the vehicle receives a sudden acceleration or deceleration force of, for example, 0.3 G or more, the inertia sensing mechanism 74 tilts the sensor weight 76 by a predetermined amount or more, and the sensing lever 7 of the pick-up link mechanism 75
Push up 7. This pushing up lock lever 42
rotates clockwise in FIGS. 2 and 11, and its lock pawl 79 engages the sensor flywheel 3.
5 and restricts rotation of the sensor flywheel 35. This rotation regulation operates in the same way as the locking operation of the webbing sensor device 30, causing the locking portion 48 of the sensor arm 44 to be engaged with the fixed internal teeth 34 of the sensor housing 33, and locking the locking device 18.

When the vehicle returns to a stable running condition where it is not stopped or subjected to large speed fluctuations, the latch ring 25 interposed between the lock teeth 21 of the retractor body 11 and the ratchet teeth 22 of the ratchet wheel 23 A large locking force due to the locking action is not applied to the latch teeth 24 of the latch ring 25.
becomes free. When the locking force is no longer applied to the latch ring 25, the latch ring 25 moves toward the latch frame 31 by the spring force of the latch spring 26, and assumes a floating state. In this floating state, the engaging piece 29 of the latch ring 25 engages with the notched tapered portion 32 of the latch frame 31, and is maintained in the floating state.

On the other hand, when the vehicle is stopped or there is no large speed change, the lock portion 48 of the sensor arm 44 does not engage with the fixed internal teeth 34 of the sensor housing 33 due to the spring force of the bar spring 49 of the webbing sensor device 30. It is held in the backward position and becomes free.

Also, at this time, the vehicle sensor device 41
The sensor weight 76 housed in the inertial sensing mechanism 74 returns to its original upright state due to its gravity. As a result, the sensing lever 77 of the pick-up link mechanism 75 that engages the sensor weight 76 swings clockwise, the lock lever 42 swings counterclockwise, and the lock pawl 79 is released from the ratchet teeth 40 of the sensor flywheel 35. .

In this way, the lock device 18, webbing sensor device 30, and vehicle sensor device 41 are returned to their original free state and are ready for the next operation.

Next, the webbing of the safety belt that has been pulled out is forcefully rewound by the spring force of the spiral spring.
A lock-up stop mechanism 58 is provided to prevent the lock-up from being activated. In this stop mechanism 58, the lock-up prevention member 59 receives frictional force from the inner circumferential wall surface of the sensor housing 33 when the webbing is retracted, and the locking projection 64 is connected to the engagement projection 50 of the sensor arm 44 in FIG.
The lock portion 48 of the sensor arm 44 is prevented from engaging with the fixed internal teeth 34 of the sensor housing 33. Therefore, when the webbing is completely rewound, the locking portion 48 of the sensor arm 44 is released from the fixed internal teeth 34 and maintained in the released state, so that the locking device 18 does not operate to lock the webbing. Re-drawing can be performed smoothly and smoothly.

When the webbing of the safety belt is pulled out, the lock-up stop member 59 of the lock-up stop mechanism 58 receives a frictional force from the inner circumferential wall surface of the sensor housing 33, and as shown in FIG. The locking protrusion 64 is moved clockwise to the sensor arm 44.
from the engaging protrusion 50. By this release, the lock-up stop mechanism 58 is released from the interlocking operation with the webbing sensor device 30, and there is no adverse effect on the webbing sensor device 30.

In addition, in the description of one embodiment of this invention,
Although an example has been described in which a sensor weight is provided as an inertial sensing mechanism of a vehicle sensor device, it is not necessarily limited to a sensor weight, and other types of inertial sensing mechanisms such as a pendulum-shaped weight, a bell-shaped weight, or an inverted conical surface are also applicable. The inertial force may be sensed by the amount of rolling of the inertial ball rolling.

Further, in the description of one embodiment, the sensor arm of the webbing sensor device is attached to the outside of the latch frame, but the sensor arm may be attached to the inside of the latch frame. Similarly, the lock-up prevention member of the lock-up stop mechanism may be mounted inside the latch frame.

〔Effect of the invention〕

As described above, in the safety belt retractor according to the present invention, the webbing sensor device detects the webbing withdrawal speed of the safety belt, and when the speed fluctuation exceeds a certain level, the sensor arm of the webbing sensor device is activated. By swinging against the spring force, the lock part of the sensor arm engages with the fixed internal teeth of the sensor housing, and the locking device is activated, so that the webbing of the safety belt is completely and reliably prevented from being pulled out. , the safety of tower passengers can be effectively ensured. At this time, the sensor arm increases the difference in rotational displacement due to the difference in inertia between the latch frame and the sensor flywheel and transmits it to the lock part, and the diameter of the sensor flywheel is not restricted by the latch frame, so The amount of inertia can be increased, and the webbing sensor function can be improved.
Even if this webbing sensor mechanism is improved, the latch frame and sensor flywheel are disk-shaped, and the sensor arm is configured in a flat shape, so even if they are stacked on top of each other, they do not require a large installation space, making the retractor more compact. can be achieved.

In addition, the sensor arm has a flat shape and is configured to bypass the shaft portion almost all the way around the shaft, so the sensor arm is arranged in a well-balanced manner all around the shaft, and centrifugal force due to rotation can prevent operation. The rotational inertia detected by the sensor flywheel can be transmitted to the lock part without being affected by centrifugal force, and the sensing function is improved.

Furthermore, since the sensor arm is flat and curved so as to go around almost the entire circumference of the shaft, the length of the arm from the center of swing to the free end is made longer to provide elasticity to the locking part of the sensor arm. The selection of whether the lock part jumps into the fixed internal teeth of the sensor housing or comes off due to the above-mentioned lock part displacement is done by the elastic deformation of the sensor arm, and the lock part stably attaches to the fixed internal teeth. You can jump in and engage.

Furthermore, the sensor arm is made of a resin material and has a simple structure, making it easy to manufacture and reducing costs.

Furthermore, the present invention provides a lock-up stop mechanism in the webbing sensor device, and connects the sensor arm to the fixed internal tooth of the sensor housing so that the lock device is not locked through the webbing sensor device when the webbing of the safety belt is retracted. Since the lock device is maintained in the retracted position in which it is not engaged, the lock device can always be kept in the released position when rewinding the webbing, and the webbing can be pulled out again smoothly and smoothly. In this case, the lock-up stop mechanism is installed using the dead space between the latch frame and the sensor flywheel, so even if the lock-up stop mechanism is provided, the retractor does not become larger. play.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a retractor for a safety belt according to the present invention, and FIG. 2 is a side view of FIG.
3 is an exploded perspective view of the safety belt retractor locking device and webbing sensor device shown in FIG. 1; FIG. 4 is a diagram showing a ratchet wheel incorporated in the retractor locking device according to the present invention; FIG. 5A is a diagram showing a latch ring incorporated in the locking device, FIG. 5B is a sectional view taken along the line AA in FIG. 5A, and FIG. 6 is a diagram showing a latch spring incorporated in the locking device. , FIG. 7A is a perspective view showing a latch frame incorporated in the retractor webbing sensor device according to the present invention;
FIG. 7B is a sectional view of the latch frame, FIGS. 8A and B are perspective views and longitudinal sectional views of the sensor arm incorporated into the webbing sensor device, and FIGS. 9A and B are the sensor arm incorporated into the webbing sensor device. FIGS. 10A and 10B are a perspective view and a right side view of a lock-up prevention member of a lock-up stop mechanism incorporated in a retractor according to the present invention, and FIG. 11 is a right side view thereof. FIG. 1 is a perspective view showing a vehicle sensor device incorporated into a safety belt retractor according to the present invention. 10... Retractor, 11... Retractor body, 1
1A, 11B... Side plate, 15... Shaft, 17... Take-up reel, 18... Lock device, 19... Spiral spring,
21... Lock tooth, 22... Latch tooth, 23... Latch wheel, 24... Latch tooth, 25... Latch ring, 26... Latch spring, 30... Webbing sensor device, 31... Latch frame, 32... Notch taper part, 33... Sensor Housing, 34... Fixed internal tooth, 35... (Ratchet) sensor flywheel, 39... Engagement hole, 40... Ratchet tooth, 41...
Vehicle sensor device, 42...Lock lever, 44
...Sensor arm, 47...Engagement piece, 48...Lock portion, 49...Bar spring, 50...Engagement protrusion, 52...Spring support, 58...Lock up stop mechanism, 5
9... Lock-up prevention member, 63... Contact engagement part,
64... Locking protrusion, 66, 67... Stopper pin, 7
4... Inertial sensing mechanism, 75... Pick up link mechanism, 76... Sensor weight, 77... Sensing lever,
78...Sensor part, 79...Lock claw.

Claims (1)

[Claims] 1. A shaft is rotatably supported between both side plates of the retractor body, a take-up reel wrapped with safety belt webbing is attached to the shaft, and the take-up reel is moved in the unwinding direction by a spring. In the safety belt retractor, a locking device is attached to one side of the shaft to energize the shaft and restrict the rotation of the shaft, and a webbing sensor device is provided to lock the locking device in accordance with the webbing withdrawal speed. The sensor device includes a lightweight disc-shaped latch frame that is loosely fitted to one side protrusion of a shaft that protrudes from a side plate of the retractor body, and a disc-shaped sensor flywheel that is loosely fitted to the shaft on the outside of the latch frame. and a swingable flat sensor arm that is mounted from the outside in the mounting hole of the latch frame and located inside the sensor flywheel,
The sensor arm is curved so as to circumvent the shaft portion almost entirely around the shaft portion, and has a raised engagement hole at one free end thereof to engage with the engagement hole of the sensor flywheel. A lock portion is formed at the other free end of the sensor arm, and the lock portion is engageable with the fixed internal teeth formed on the inner circumferential wall of the sensor housing. When the safety belt is suddenly pulled out, the sensor flywheel that senses the pulling force swings the sensor arm against the spring force and locks the sensor arm in the retracted position. A retractor for a safety belt, characterized in that the latch frame engages with the fixed internal teeth, thereby causing the latch frame to lock the locking device. 2. The lock part of the sensor arm has a thick wall structure and is accommodated in the outer circumferential notch of the latch frame, while the rod spring that biases the lock part toward the retracted position where it does not engage with the fixed internal teeth of the sensor housing is located at both ends. A safety belt retractor according to claim 1, wherein the safety belt retractor is supported by a latch frame. 3. The safety belt retractor according to claim 2, wherein the sensor arm is molded from a resin material such as 6-6 nylon containing glass fiber. 4. A shaft is rotatably supported between both side plates of the retractor body, a take-up reel wrapped with safety belt webbing is attached to the shaft, the take-up reel is biased by a spring in the rewinding direction, and In a safety belt retractor, a webbing sensor device is installed on one side of the shaft to restrict rotation of the shaft, and a webbing sensor device is provided to lock the lock device in accordance with the withdrawal speed of the webbing. A disc-shaped latch frame loosely fitted to one side protrusion of a shaft protruding from a side plate of the main body; a lightweight disc-shaped sensor flywheel loosely fitted to the shaft on the outside of the latch frame; a swingable flat sensor arm that is mounted in the mounting hole from the outside and located inside the sensor flywheel;
The sensor arm is curved so as to bypass the shaft portion, and an engagement piece is formed at one free end of the sensor arm to engage with an engagement hole of the sensor flywheel, and the other is provided with an engaging piece that extends upwardly so as to engage with an engagement hole of the sensor flywheel. The side free end portion is formed with a lock portion that can engage with fixed internal teeth formed on the inner circumferential wall of the sensor housing, while the sensor arm is spring-loaded to a retracted position where the lock portion does not engage with the fixed internal teeth. A lock-up stop mechanism is mounted on the latch frame in a dead space between the latch frame and the sensor flywheel, and the lock-up stop mechanism closes the sensor arm when the webbing is unwound. A retractor for a safety belt, characterized in that the stop portion of the safety belt is prevented from engaging with the fixed internal teeth. 5. The lock-up stop mechanism has a lock-up prevention member that is pivotably mounted on the latch frame, and the lock-up prevention member has a contact engagement portion that can be pressed into contact with the inner peripheral wall surface of the sensor housing, and a sensor arm. 5. The safety belt retractor according to claim 4, having a stepped portion on one side of the engaging portion and an engageable locking protrusion. 6. The safety belt retractor according to claim 5, wherein the latch frame is provided with a pair of stopper pins at appropriate intervals in the circumferential direction for regulating the swinging stroke of the lock-up prevention member. 7 The lock-up prevention member is made of a resin material such as plastic, and has a U-shaped curved portion that protrudes on both sides between the shafting portion and the contact engagement portion. 6. The safety belt retractor according to claim 5, wherein the contact engagement portion is configured to elastically press and contact the inner circumferential wall surface of the sensor housing.