JPH0427718Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a webbing-sensitive emergency locking mechanism for a seatbelt emergency locking retractor.

In general, emergency locking retractors include a webbing-sensitive type that locks by rapidly pulling out the webbing, a vehicle-body-sensitive type that locks by detecting acceleration applied to the vehicle body, and a dual type that has both functions. It is known for its sense of style. The present invention provides an emergency lock mechanism applicable to webbing sensitive type and dual sense.

BACKGROUND OF THE INVENTION Various types of webbing-sensitive emergency lock mechanisms for retractors have been known, one example of which is the one described in Japanese Utility Model Application Publication No. 71656/1983. In this device, a rotating base is fixed to a webbing take-up shaft so as to rotate integrally, and an inertia weight is provided coaxially with the rotating base to allow slight rotation between the rotating base and the rotating base. The synchronous pawl is supported by the synchronous pawl and an inertia weight, and the synchronous pawl is caused to protrude outward by rotating the inertia weight relative to the rotating base, and when the synchronous pawl protrudes, it engages the sensor. The sensor is rotated at the same time, and the rotation of the winding shaft is locked in conjunction with the rotation of the sensor.

Problems to be Solved by the Invention In general, in this type of emergency lock mechanism, there is a possibility that an end-lock phenomenon may occur. This end-lock phenomenon occurs when the seat belt is released and the webbing is wound onto the retractor, and the take-up shaft suddenly stops at the end of the retractor. This refers to the phenomenon in which the device becomes locked. This phenomenon is not limited to the above-mentioned conventional mechanism, but always has the possibility of occurring in a webbing-sensitive emergency lock mechanism.

The webbing-sensitive emergency locking mechanism operates when the webbing is rapidly pulled out, locks the retractor, and releases the lock by releasing the webbing pulling force and retracting the webbing. However, if the webbing is locked with the webbing retracted to the end, the retractor will not be able to retract it any further, so the lock cannot be resolved if the retractor is unable to retract it any further.

The conventional mechanism described above has a mechanism for preventing this end lock, but a complicated mechanism is required to prevent the end lock. In the prior art example as well, a mechanism is employed that detects the amount of webbing taken up and blocks the lock when the amount of taken up is larger than a predetermined amount. This requires a blocking mechanism and a mechanism for connecting these mechanisms, making it extremely complicated.

In addition, in the emergency lock mechanism that does not have an end lock prevention mechanism as described above, when an end lock phenomenon occurs, the webbing is usually pulled strongly and the webbing wound around the retractor is further tightened, and the webbing is pulled out by that amount. The end lock is released by rewinding the webbing into the retractor. However, conventional retractors on the market require a margin of more than ten millimeters to release the end lock, and in order to create that much margin by tightening the webbing in the retractor, , it was necessary to pull the webbing with an extremely large force, and women and children who were weak were sometimes unable to release the end lock.

The present invention was developed in view of the above circumstances, and although it does not have a function to prevent the end lock phenomenon when the webbing is reeled in, even if the end lock phenomenon occurs, it can easily eliminate the end lock by simply pulling the webbing slightly. It is an object of the present invention to provide a webbing-sensitive emergency locking mechanism that can be used as an emergency lock mechanism.

Means for Solving the Problems The present invention includes a lock arm keeper that rotates together with a webbing take-up shaft of a retractor, and a lock arm keeper that is rotatably supported with respect to the take-up shaft and that is rotatably supported relative to the webbing take-up shaft. an inertia mass that is rotatable within a predetermined range, a main body of which is slidably supported relative to the inertia mass at a position close to the rotation axis of the inertia mass, and a branch protruding from the center of the main body. is pivotably supported by the lock arm keeper at a position close to the outer periphery of the inertia mass, and a claw formed at one end of the main body portion protrudes from the outer periphery of the inertia mass by rotation of the lock arm keeper in the direction of pulling out the webbing with respect to the inertia mass. a lock arm; a spring means for biasing the lock arm against the lock arm keeper in a rotational direction when the webbing is drawn; a clutch having internal teeth that rotate the webbing, and a locking means for stopping the rotation of the winding shaft when the clutch rotates in the webbing drawing direction, and an engagement surface between the pawl of the lock arm and the internal teeth of the clutch. is characterized in that it is inclined in the direction in which the lock arm is disengaged with respect to the sliding direction of the lock arm relative to the inertia mass.

The present invention will be explained below with reference to the drawings. The drawing shows an emergency lock type retractor to which the emergency lock mechanism of the present invention is applied. Reference numeral 1 denotes a retractor main body, with side plates 3 and 4 erected on both side edges of a bottom plate 2, and a reel 5 rotatably suspended between the side plates 3 and 4. The reel 5 has ratchet wheels 7, 7 fixed to both ends of a webbing take-up shaft 6, and both ends of the take-up shaft 6 project laterally from the side plates 3, 4.

The inner end of a full-length spring 8 is attached to the protrusion from one side plate 3 of the winding shaft 6, and the outer end of the full-length spring 8 is locked to the inner surface of a barrel 9. The reel 5 is given a rotational force in the webbing winding direction (clockwise in FIG. 2) by the elasticity of the webbing. Further, the protruding portion of the winding shaft 6 from the other side plate 4 is provided with an emergency lock mechanism of the present invention.

The protrusion of the winding shaft 6 from the side plate 4 includes
A lock arm keeper 10 is fixed to rotate together with the winding shaft 6. The lock arm keeper 10 has a substantially elliptical shape, and has a protrusion 11 protruding from one end and a stopper 12 protruding from the other end.

Reference numeral 13 denotes a lock arm, which is approximately T-shaped and includes a rod-shaped main body portion 14 and a branch portion 15 projecting laterally from the center of the main body portion 14.
A claw 16 is formed at one end of the main body portion 14, and the protrusion 11 of the lock arm keeper 10 is loosely fitted into a hole 17 formed at the tip of the branch portion 15, allowing the main body portion 14 to be attached to the winding shaft. 6 and across the lock arm keeper 10.

18 is inertia mass. The inertia mass 18 is a metal disc-shaped member, and is rotatably supported on the winding shaft 6.
A recess 19a is formed in the side surface of the recess 19a.
A part of a forms a groove 19. The groove 19
The lock arm 13 is slidably fitted in the main body portion 14 in the longitudinal direction, and the stopper 12 of the lock arm keeper 10 is fitted in the recess 19a.
The inertia mass 18 can be rotated within a limited range with respect to the lock arm keeper 10.

Then, as the lock arm keeper 10 rotates relative to the inertia mass 18 in the direction of pulling out the webbing, the lock arm 13 rotates relative to the lock arm keeper 10 and the main body portion 14
slides along the groove 19, and the claw 16 protrudes from the outer periphery of the inertia mass 18.
The lock arm 13 is biased by spring means 20 against the lock arm keeper 10 in the direction of pulling out the webbing.

Reference numeral 21 denotes a clutch rotatably supported on the winding shaft 6, and on the outer periphery of the surface of the clutch 21 facing the inertia mass 18,
Internal teeth 22 that engage with the pawl 16 of the lock arm 13 when the pawl 16 protrudes from the inertia mass 18.
An annular rib 23 is provided in a protruding manner. The engagement surfaces 24 and 25 between the pawl 16 and the internal teeth 22 are inclined in the direction in which the engagement is released with respect to the sliding direction of the main body portion 14 of the lock arm 13. Further, on the outer periphery of the clutch 21, a protrusion 27 having a locking hole 26 is formed.
is installed protrudingly.

Reference numeral 28 denotes a pawl that is swingably installed between the side plates 3 and 4 of the retractor main body 1, and has an engaging pawl 29 that engages with the ratchet wheels 7 and 7, and has a spring means 30. The ratchet wheels 7, 7 are always biased in the non-engaging direction by the latch wheels 7, 7. An arm 31 is attached to one end of the pawl 28 protruding from the side plate 4, and a protrusion 32 formed at the tip of the arm 31 is connected to the protrusion 2 of the clutch 21.
The pawl 28 is loosely fitted into the locking hole 26 of 7, and the pawl 28 is rotated in the direction of pulling out the webbing.
by swinging the engaging pawl 29 to the ratchet wheel 7.
The winding shaft 6 is engaged with the winding shaft 6 to lock the rotation of the winding shaft 6.

The present invention is a webbing-sensitive emergency locking mechanism, but in the retractor shown in the drawing,
In addition, it is equipped with a body-sensitive emergency lock mechanism. That is, a locking gear 33 is fitted around the outer periphery of the inertia mass 18, and is frictionally engaged with the inertia mass 18 by a wire spring 34. Reference numeral 35 is an acceleration sensor, and when an acceleration exceeding a predetermined limit is applied to the vehicle body, a weight 36 swings, and a mechanical lever 37 placed on the weight 36 is pushed up. The claw 38 is engaged with the locking gear 33.

39 is a cover that covers the mechanism of the present invention.

Operation The operation of the present invention will be explained below. Figures 1 to 3
The figure shows the mechanism of the invention in an inoperative state. First, the lock arm keeper 10 is moved by the elasticity of the spring means 20.
is rotating in the webbing winding direction relative to the inertia mass 18, and the lock arm 13 is rotating in the webbing winding direction with respect to the inertia mass 18.
is retracted from the outer periphery of the inertia mass 18. Also, due to the elasticity of the spring means 30, the pawl 28 assumes a disengaged position with respect to the ratchet wheel 7, and the clutch 21 is in a rotated position in the webbing retraction direction. Therefore, the winding shaft 6 can freely rotate relative to the retractor body 1, pulling out the webbing from the retractor, and also winding up the retractor by the elasticity of the spring 8.

Next, when the webbing is suddenly pulled out, the take-up shaft 6 is suddenly rotated in the webbing pulling direction. Since the lock arm keeper 10 is integrated with the take-up shaft 6, it rotates together with the take-up shaft 6, but the inertia mass 18 causes a delay in rotation due to inertia, and the lock arm keeper 10 rotates in the webbing drawing direction relative to the inertia mass 18. I will do it.

Furthermore, since the lock arm 13 can only slide relative to the inertia mass 18 and not rotate, the lock arm 13 resists the elasticity of the spring means 20 and rotates relative to the lock arm keeper 10 while rotating against the groove 19 of the inertia mass 18. 4, the pawl 16 protrudes from the outer periphery of the inertia mass 18 and engages with the internal teeth 22 of the clutch 21, as shown in FIG.

When further rotational force is applied to the take-up shaft 6 in this state, the take-up shaft 6, lock arm keeper 10, lock arm 13, and inertia mass 18 rotate as one, and the clutch 21 engaged with the pawl 16 also rotates as one. It rotates in the webbing drawer direction. As a result of the rotation of the clutch 21, the locking hole 26 of the protrusion 27 swings the pawl 28 clockwise in the figure via the arm 31, and the engaging pawl 29 engages with the ratchet wheel 7, causing the winding to take place. This locks the rotation of the shaft 6. This state is shown in FIG.

Next, when the tensile force on the webbing is released, the take-up shaft 6 rotates in the webbing winding direction due to the elasticity of the spring 8, and the engagement of the ratchet wheel 7 with the pawl 28 is released. On the other hand, as the winding shaft 6 rotates, the lock arm keeper 10 also rotates in the webbing winding direction.
The engagement between the pawl 16 and the internal teeth 22 of the clutch 21 is also released. As a result, the relationship between the lock arm keeper 10, the lock arm 13, and the inertia mass 18 becomes free, and the elastic force of the spring means 20 causes the lock arm 13 to rotate relative to the lock arm keeper 10 in the direction of pulling out the webbing.
Correspondingly, the inertia mass 18 also rotates in the same direction, and the claw 16 of the lock arm 13 is retracted from the outer periphery of the inertia mass 18.

Further, the clutch 21 is also disengaged from the pawl 16 of the lock arm 13, so that it becomes free, and the pawl 28 swings in the disengaged direction with respect to the ratchet wheel 7 due to the elasticity of the spring means 30. Along with this, the webbing is rotated in the webbing winding direction, and returns to the state shown in FIGS. 1 to 3, and the webbing can be freely pulled out and rolled in again.

Further, when a large acceleration is applied to the vehicle body in the retractor shown in the drawings, the weight 36 swings, the mechanical lever 37 is pushed up, and the pawl 38 assumes an engagement position with respect to the locking gear 33. When the webbing is pulled out in this state and the take-up shaft 6 rotates, the lock arm keeper 10, lock arm 13 and inertia mass 18 are removed as described above.
rotate together with the winding shaft 6,
Further, the locking gear 33 that is frictionally engaged with the inertia mass 18 also rotates together with them, but when the locking gear 33 engages with the pawl 38 of the mechanical lever 37, its rotation is stopped. The rotation of the inertia mass 18 frictionally engaged with the locking gear 33 is also stopped.

Then, when the take-up shaft 6 rotates further,
Lock arm keeper 1 is integrally fixed to this
0 rotates, but since the inertia mass 18 does not rotate, the lock arm keeper 10 rotates relative to the inertia mass 18 in the webbing drawing direction. Therefore, the lock arm 13 slides along the groove 19 against the elasticity of the spring means 20, and the pawl 16 projects from the outer periphery of the inertia mass 18, and the pawl 16 engages with the internal teeth 22 of the clutch 21. Hereinafter, similarly to the webbing-sensitive type described above, the clutch 21 rotates to swing the pawl 28, and the engaging pawl 29 engages with the ratchet wheel 7 to lock the rotation of the winding shaft 6. be.

In the present invention, when the webbing is released and wound into the retractor, the lock arm keeper 10, lock arm 13, and inertia mass 18 rotate together with the winding shaft 6 in the webbing winding direction, that is, clockwise in the drawing. When the webbing is completely retracted into the retractor, the rotation of the take-up shaft 6 immediately stops, and along with this, the rotation of the lock arm keeper 10 also stops abruptly. However, inertia mass 1
8 may continue to rotate a little further due to inertia, and at that time, the lock arm 13 fitted in the groove 19 also resists the elasticity of the spring means 20 and rotates the protrusion 1.
The claw 16 rotates around the inertia mass 1.
It protrudes from the outer periphery of 8.

Even if the pawl 16 protrudes, it usually returns to its original state due to the elasticity of the spring means 20. However, depending on the position of the pawl 16 at the time of protrusion, the protruding pawl 16 may touch the internal teeth 22 of the clutch 21. They may get engaged. In such a state, when you try to pull out the webbing next time to fasten the seat belt, the clutch 21 rotates because the pawl 16 is engaged with the internal teeth 22, causing the pawl 28 to swing and engage. Since the matching pawl 29 engages with the ratchet wheel 7, the webbing cannot be pulled out, and an end lock phenomenon may occur.

In this case, by strongly pulling the webbing, the webbing wound around the retractor is tightened, and some of the webbing can be pulled out. The end lock can then be released by rewinding the pulled out webbing.

Effects of the invention If the conventional mechanism does not have an end lock prevention mechanism, the lock arm 13 is directly supported by the lock arm keeper 10, so in order to release the engagement between the lock arm 13 and the clutch 21, it is necessary to It was necessary to rotate the arm keeper 10 over a considerably large angle with respect to the inertia mass 18, and to do so, it was necessary to wrap the webbing over a considerable length. Therefore, it was necessary to pull out that long webbing by tightening the webbing in the retractor, which required an extremely large amount of force.

When the support position of the lock arm 13 in the lock arm keeper 10 is set close to the rotation axis of the lock arm keeper 10, the internal tooth 22 of the clutch 21 can be locked by simply sliding the lock arm 13 slightly.
However, in order to move the lock arm 13 even slightly, the lock arm keeper 10 must be rotated sufficiently. Conversely, if the support position of the lock arm 13 is set near the terminal of the lock arm keeper 10, the sliding distance of the lock arm 13 can be increased with respect to the rotation angle of the lock arm keeper 10, but conversely, the claw 16 can be In order to remove the lock arm 13 from the teeth 22, it is necessary to move the lock arm 13 over a large distance, and as a result, the rotation angle of the lock arm keeper 10 must be considerably large.

On the other hand, in the present invention, the lock arm 1
3 is a substantially T-shaped member, and is supported near the end of the lock arm keeper 10 at the tip of the branch portion 15, and the main body portion 14 is disposed near the rotation axis of the lock arm keeper 10. Since the lock arm 13 can be slid over a relatively large distance by only slightly rotating the lock arm keeper 10, and the distance for the lock arm 13 to be extracted from the internal teeth 22 is small, a slight rotation of the lock arm keeper 10 is required. Depending on the nail 1
6 and the internal teeth 22 can be disengaged from each other.

Further, according to the present invention, since the engaging surfaces 24 and 25 between the pawl 16 and the internal teeth 22 are inclined in the direction in which the engagement is released with respect to the sliding direction of the main body portion 14 of the lock arm 13, the winding When the shaft 6 rotates slightly and the engagement between the pawl 28 and the ratchet wheel 7 is released, sliding between the engaging surfaces 24 and 25 immediately begins, and while the winding shaft 6 rotates very slightly, The engagement between the pawl 16 and the internal teeth 22 is released.

Therefore, according to the present invention, the rotation angle of the winding shaft 6 required to eliminate the end lock is small, and accordingly, the amount of winding of the webbing required for this purpose is also small. Therefore, even if an end lock occurs, if the webbing in the retractor is tightened and a small amount of webbing is pulled out, the end lock can be resolved by rewinding it again. The force is small.

Experiments have shown that with a conventional retractor that retracts 1450 mm of webbing, it is necessary to pull the webbing with a force of 7 to 8 kg and pull out 11 to 12 mm of webbing in order to eliminate the end lock. The retractor that uses the invented mechanism pulls the webbing with a force of approximately 3.5 kg, and the webbing is approximately 4 mm
By simply pulling out the webbing, the end lock could be resolved by rewinding the webbing.

Therefore, according to the present invention, even if endlock occurs, it can be easily resolved, and even women and children who are weak can easily resolve it. In addition, there is no need for a complicated mechanism to prevent end-locking, and only slight improvements are made to the conventional locking mechanism, so an increase in cost can be avoided.

In addition, in the dual sense retractor shown in the drawing, when the rotation of the shear shaft 6 suddenly stops at the end of winding the webbing,
The impact may cause the mechanical lever 37 to jump up, causing the pawl 38 to engage the locking gear 33, resulting in an end-lock phenomenon. Even in this case, the end lock can be easily released according to the present invention, but the shape of the teeth of the locking gear 33 is designed so that the engagement of the pawl 38 can be easily disengaged.
8 is preferably disengaged from the locking gear 33.

[Brief explanation of drawings]

The drawings show a retractor employing the emergency locking mechanism of the present invention, in which Fig. 1 is a central vertical sectional view, Fig. 2 is a right side view showing the cover in cross section,
FIG. 3 is a sectional view taken in FIG. 1, and FIG. 4 is a sectional view showing the main parts of the emergency lock mechanism in an activated state. 6... Winding shaft, 7... Ratchet wheel, 10... Lock arm keeper, 13...
Lock arm, 14... Main body part, 15... Branch part, 16... Claw, 18... Inertia mass, 20
... Spring means, 21 ... Clutch, 22 ... Internal teeth, 24, 25 ... Engagement surface, 28 ... Pawl.

Claims (1)

[Scope of utility model registration request] A lock arm keeper 10 rotates together with the webbing take-up shaft 6 of the retractor, and the lock arm keeper 10 is rotatably supported relative to the take-up shaft 6 and is rotatable within a predetermined range relative to the lock arm keeper 10. The main body portion 14 is slidably supported on the inertia mass 18 at a position close to the rotation axis of the inertia mass 18, and a branch portion 15 protruding from the center of the main body portion 14 is attached to the inertia mass 18. is pivotably supported by the lock arm keeper 10 at a position close to the outer periphery of the main body portion 14, and as the lock arm keeper 10 rotates in the direction of pulling out the webbing with respect to the inertia mass 18, a pawl 16 formed at one end of the main body portion 14 moves the inertia mass 18. A lock arm 13 protruding from the outer periphery and the lock arm 1
3 against the lock arm keeper 10 in the direction of rotation when the webbing is drawn out;
0, and a clutch 2 rotatably supported with respect to the winding shaft 6 and having internal teeth 22 that engage with the pawl 16 of the lock arm 13 when the lock arm 13 is extended.
1, and locking means 28, 7 for stopping the rotation of the winding shaft 6 when the clutch 21 rotates in the direction of pulling out the webbing,
The pawl 16 of the lock arm 13 and the clutch 2
An emergency locking mechanism for a retractor, characterized in that engaging surfaces 24 and 25 that engage with the internal teeth 22 of the retractor 1 are inclined in a direction in which the engagement is released with respect to the sliding direction of the lock arm 13 with respect to the inertia mass 18.