JPS63212151A - Emergency take-up device for safety belt - Google Patents

Abstract

PURPOSE:To enable positive take-up by constituting a pre-loading mechanism which forcibly rotates a drum in the direction of take-up with the blow-up of explosive simultaneously with the operation of a locking mechanism in an emergency, so as to rotate the drum by way of the engagement of an engaging projection with a recess. CONSTITUTION:When an excessive impact is applied on account of the collision of a vehicle, a cartridge 18 bursts out in a gas generator 19 by the output from a means for detecting the impact, thereby raising a piston 20 in a cylinder 16 upward. A belt 21 is pulled in following the movement of the piston 20, the belt body 2 standing by at intervals around the circumference of a drum 14 is brought in close contact with the drum 14 wherein the engaging recess of the belt body 21 is engaged with the engaging recess 24 of the drum 14, thereby the drum 14 is rotated in the direction of belt rewinding. And this rotation will not stop before a braking force is applied to the piston 20 at a tapered part near the upper end of a cylinder 16, thereby the length corresponding to the shortage of the tight rewinding of a belt 36 is taken up onto a take-up shaft 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an emergency winding device for safety belts installed on automobile seats and the like.

Conventional technology In general, automobile safety belts (seat belts) protect occupants in the event of a collision by restraining them in their seats.In the event of an emergency such as a collision, the safety belts (seat belts) of automobiles detect abnormal movement of the vehicle body and activate the locking mechanism. It has a retractor that operates to stop belt withdrawal. Therefore, in normal situations other than emergencies, the locking mechanism does not operate, and the belt winding mechanism operates to ensure that the belt is always wound around the occupant, so that the belt is wound around the retractor, or an attached memory mechanism is used to secure the belt to the occupant. This ensures that the belt remains snug and does not make the occupant feel restrained by the belt.

However, according to conventional glue tractors, even if the locking mechanism is activated in an emergency and the winding mechanism is locked and belt withdrawal is stopped, the belt winding is done by the force of the spring, and the belt is unwinded. Since it is wound loosely on the reel of the mechanism, it is not so-called sand-tightened, but is loose, and even after the winding mechanism is locked, the belt on the reel is tightened as the passenger's body moves forward. , the phenomenon that the belt is pulled out slightly (film
spool effect). When such a phenomenon occurs,
The belt is pulled out from the retractor that much more,
As a result, the amount of forward movement of the occupant increases, and there is a risk that the occupant's head may collide with the steering column or dash board, which is unfavorable from a safety standpoint.

Therefore, tractors have been provided that are equipped with a preload mechanism that forcibly rotates the winding shaft in the winding direction by exploding gunpowder at the same time as the locking mechanism operates in an emergency (for example, Japanese Patent Application Laid-Open No. 57-128169). This preload mechanism consists of a force accumulator consisting of a cylinder having a rupture member that changes internal pressure and a piston inserted in the axial direction of the cylinder, a wire connected at one end to the piston, and a winding shaft around which the wire is loosely wound. and an energy converter consisting of a roller pivoted to the. The other end of the wire is a free end that is loaded with enough force to wrap around the roller.

In the above preload mechanism, in an emergency, the rupture member ruptures inside the cylinder, and the piston is moved by the change in cylinder pressure, and the wire connected to the piston rotates the roller in the winding direction, which causes the winding shaft to wind the belt. This eliminates the problem of the Filmsbourg effect of the belt, and prevents the belt from being pulled out at all when the locking mechanism operates.

Problems to be Solved by the Invention However, according to the above preload mechanism, the rotation of the roller is achieved by friction between the circumferential surface of the roller and the wire, but since the roller is attached to the winding shaft, the winding is always prevented. Since it rotates as a unit with the take-up shaft, it is necessary to prevent friction between the roller and the wire during normal operations other than when the belt is attached or in an emergency. Therefore, the other end of the wire is wound loosely around the roller as a free end to which a load is applied to the extent that a force is generated. However, in this configuration, the rollers have to be driven by the frictional engagement between the wire and the rollers, which causes slippage between the two and prevents sufficient rotational force from being transmitted to the rollers, resulting in poor efficiency. , and there is little certainty.

Means for Solving the Problems The present invention aims to solve the above-mentioned problems, and involves winding up a retractor body using a drum in which a plurality of engaging protrusions and any one of four parts are formed at predetermined intervals in the radial direction. A flexible band is attached to a shaft and has a plurality of engaging protrusions and recesses formed at predetermined intervals in the longitudinal direction, the other being removable from one of the engaging protrusions and recesses. The belt is wound with a distance in the radial direction sufficient to allow normal rotation of the drum, and a prime mover is provided at one end of the belt to pull the belt and wind and rotate the drum in the event of an emergency. This is an emergency safety belt retracting device characterized by being connected.

According to the present invention, in an emergency, when the prime mover pulls the strip and the strip wraps around the drum, the engaging convex portion and the engaging concave portion engage to forcibly rotate the drum, thereby ensuring the winding shaft. Rotate it. Under normal conditions, the band moves away from the drum due to its flexibility and does not interfere with the rotation of the drum.

Example The present invention will be explained below based on the drawings and examples.

FIG. 1 shows an embodiment in which the present invention is applied to an emergency locking retractor (hereinafter abbreviated as ELR). That is, shaft support holes Ib and tb are provided in opposing walls of the ELR housing 1,
A housing pawl 1a provided with circular teeth extending in the same direction as a plurality of shafts is provided around the circumference of one of the shaft support holes 1b.
is provided. A seatbelt take-up shaft 2, to which an end of a seat belt (not shown) is fixed, is rotatably inserted into the shaft support holes tb, tb with one end protruding from the housing l, and the take-up shaft 2 is rotationally biased in the seat belt winding direction by a winding spring (not shown). A shaft wheel 3 is fixed to the protruding base of the winding shaft 2, and a shaft pawl 3 is provided on the circumference of the shaft wheel 3, which is located inside the housing pawl 1a and extends in the same direction as the shaft.
A is provided. On the other hand, the housing 1 has a cylindrical body 4 having internal teeth 4 on its inner circumference, and a housing claw 1.
A is located on the inside and fixed, and claws 5a of a known emergency locking mechanism 5 which operates by sensing the acceleration of the vehicle body are provided in several stages on the housing l. Furthermore, inside the cylinder 4,
The shaft claw 3a and the housing claw 1 are provided on the outer periphery.
A lock plate 6 having outer circumferential teeth 6a that can be engaged with a and an inner circumferential fi6b provided on the inner circumferential portion is arranged to face the shaft wheel 3, and the lock plate 6 and the shaft wheel A spring 7 interposed between the shaft claws 3 and 3 restricts the outer tooth 6a to a position where it engages only the shaft claw 3a. The winding shaft 2 has lock teeth 8a on the outer periphery inside the cylinder 4, with which the claws 5a of the emergency locking mechanism 5 engage, and lock teeth 8a on the inner periphery as shown in FIG. A cam wheel 8 having a cam surface 8b on which the inner circumferential teeth 6b of the lock plate 6 slide to move the lock plate 6 to the housing pawl la engagement site is fitted so as to be slightly rotatable. Furthermore, the cam wheel 8
The cam wheel 8 is pivotally attached to a portion that closes an opening provided on its periphery and can protrude in the outer circumferential direction. A ball 9 is provided to prevent the
It is biased back by λ. Also this cam wheel 8
An inertia plate 10 that rotates together with the cam wheel 8 and can be freely displaced by a required angle in the rotational direction, and that presses the inside of the ball 9 and causes the ball 9 to protrude by the displacement, is loosely fitted inside the cam wheel 8. There is. In the ELR having the above configuration, when the seat belt is unrolled at a rapid speed due to a vehicle collision or the like when the seat belt is attached, the winding shaft 2 and the shaft wheel 3. lock plate 6,
Cam wheel 8 rotates. At this time, the inertia plate 10 rotates in the opposite direction relative to the cam wheel 8 due to its inertia, and the inertia plate 10 presses the balls 9 and causes them to protrude in the outer circumferential direction. is engaged with the internal teeth 4a of the cylindrical body 4, and rotation of the cam wheel 8 is prevented. On the other hand, the winding shaft 2. Shaft wheel 3. Since the lock plate 6 is about to rotate further, the lock plate 6 relatively rotates in the seat belt pulling direction, so that the inner circumferential teeth 6b of the lock plate 6 are guided in sliding contact with the cam surface 8b, and the lock plate 6 is pressed and moved in one direction of the housing.

As a result of this movement, the outer circumferential tooth 6a engages with the shaft pawl 3a on the base end side and with the housing pawl 1a on the other side of the distal end, thereby preventing rotation of the winding shaft 2 and performing an emergency lock. This prevents the seat belt from being pulled out and restrains the occupant's body to the seat.

In the above configuration, the ball 9 of the cam wheel 8 and the leaf spring 9a may be replaced with a composite ball 90 formed integrally with them as shown in FIG. This ball 90 has an elastic spring portion 91 protruding from its tail end, thereby reducing the number of parts and assembly man-hours.

On the other hand, a preload mechanism 11 is attached to the ELR having the above configuration. As shown in FIG. 1, this preload mechanism consists of a prime mover I fixed to the other side wall of the housing
2, cases 13 and 13a, and a drum 14 which is pivotally attached to the winding shaft 2. The prime mover 12 is shown in FIGS. 4 and 5.
As shown in the figure, a cylinder 16 with a cap 15 on the upper end, a gas generator I9 having a chamber 17 communicating with the inside of the cylinder 16, and a chamber I7 loaded with a medicine package 18 and closed; A piston 20 inserted in the axial direction inside the cylinder 16, a band 21 whose one end is connected to the piston 20 with a pin 20a, and a housing! The holder 22 is fixed to the side wall of the holder 22. The cylinder 16 has a slightly tapered portion covered by the cap 15 and is open at the upper end. The piston 20 is the gas generator 19
It rests on the stopper part 19a slightly above the chamber 17,
Gas generator 19 is coupled to the lower end of cylinder 16. The band member 21 extends outward from the piston 20 through the slit 19b of the gas generator 19 to form a drum!
It is made of a metal such as stainless steel or a synthetic resin such as nylon resin, which is loosely wound around the shaft 4, and has an engaging recess 23 consisting of a plurality of through holes at predetermined intervals in the longitudinal direction. The band 21 has flexibility so that when the drum 14 normally rotates,
A bending force is generated which tends to separate the drum I4 in the radial direction so as not to impede its rotation. On the other hand, the drum 14 to which the band member 21 is engaged and disengaged has an engaging convex portion 24 consisting of a plurality of pins that protrude in the radial direction at predetermined intervals. The diameters of the bottle and the through hole are approximately the same, and the drum 14 has the same function as a so-called sprocket. This drum 14
is attached to one end of the winding shaft 2 via a collar 25. The collar 25 and the drum 14 fit on the outer peripheral surface and the inner peripheral surface of the shaft hole 26, respectively, with serrations 27 and 28. The case I3 includes a chamber 29 for storing the drum 14 and the band 21, and a chamber 30 communicating with the chamber 29,
A neck portion 31 is formed between the compartments 29 and 30 to pinch the band 21 and apply a constant load. This neck portion 31 consists of an arcuate protrusion on which the band 21 slides. Case 1
3.degree. 13a is fixed to the side wall of the housing 1 via screws 32. 33 is a guide pin or roller for the band, and 34 is a wheel for hanging the other end of the band 2I without connecting it.

If an appropriate load is applied to the wheel 34, the neck portion 31 may not need to be formed. Note that the gas generator 19 is connected to a wiring 35 that sends an electric signal detected by a suitable vibration sensing device, and a configuration is adopted in which the medicine package can be ruptured by the electric signal.

Next, the operation of the preload mechanism 11 will be explained. When excessive vibration is applied to the vehicle body due to a vehicle collision as described above, the vibration sensing device acts and the medicine package 18 ruptures within the gas generator I9. Figure 6A). When the cartridge 18 bursts, the generated gas pushes the piston 20 upwards into the cylinder 16, and the piston 20 draws the strip 21 into the cylinder I6 (FIG. 6B). Then, the band 21 is wrapped around the drum 14, the engagement recess 23 and the engagement protrusion 24 are engaged, and the drum! 4 rotates in the winding direction of the belt 35, and the winding shaft 2 winds up the belt 36. and,
The piston 20 rises until it is braked and stopped at the tapered part near the upper end of the cylinder 16 (FIG. 6C), and the belt 3
The length corresponding to the insufficient winding of 6 is wound onto the winding shaft 2.

After the belt 36 of a predetermined length is wound in this manner, the webbing sensor is activated and the belt 36 is locked so that it cannot be pulled out.

The engaging convex portion 24 is connected to the engaging concave portion 23 on the drum 14.
are formed on the band body 21, but depending on the case, the engagement recesses 23 and the engagement protrusions 24 may be formed on the drum 14 and the band body 21, respectively. Further, the engagement recess 24 is not limited to a through hole, and may be a simple hole such as a depression. Furthermore, a band may be formed in which teeth are formed on the circumferential surface of the drum 14 and teeth that mesh with the teeth are formed on a band, that is, a timing belt-like band. In addition, the gas generator 1 as the prime mover
Instead of 9, it is also possible to utilize the force generated by the spring that has accumulated pressure.

Effects of the Invention According to the present invention described above, the preload mechanism is such that the drum fixed to the winding shaft and the band member that rotates the drum in the winding direction in an emergency are engaged with each other through the engaging convex portion and the concave portion. Since the output of the prime mover is efficiently transmitted to the take-up shaft without slipping between the drum and the belt, the emergency winding amount of the belt of the retractor cannot avoid the Filmsbourg effect problem. This significantly improves occupant restraint performance.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a tractor implementing the present invention, FIG. 2 is a perspective view of the components shown in FIG. 1 at different angles, and FIG.
The drawings are a front view showing another example of the components in Fig. 1, Fig. 4 is a longitudinal sectional front view of the main part of the present invention, Fig. 5 is a longitudinal sectional side view of the main part, and Figs. 6 (A) and (B). . (C) is an explanatory diagram of the operation of the main part. 2... Winding shaft! ■・・・Preload mechanism,
I2... Prime mover, 13.13a... Case, 14.
... Drum, 15... Cap, 16... Cylinder, 18... Medicine package, 19... Gas generator, 20
...Piston, 21...Band body, 22...Holder, 23...Engagement recess, 24...Engagement protrusion, 25...
・Color, 29.30... Chamber, 31... Neck part,
33...Guide bin, 34...Wheel, 35...
・Wiring, 36...Belt. Figure 2 Figure 3 Procedural Amendment <s, Rejected April 6, 1986 [1

Claims (1)

[Claims] A drum having one of a plurality of engagement protrusions and recesses formed at predetermined intervals in the radial direction is pivotally attached to a winding shaft of a retractor body, and is capable of being engaged with and detached from one of the engagement protrusions and recesses. A flexible band having one of a plurality of engagement protrusions and a plurality of recesses formed at predetermined intervals in the longitudinal direction is wound with a distance in the radial direction sufficient to allow normal rotation of the drum, and An emergency retracting device for a safety belt, characterized in that one end of the belt is connected to a prime mover that pulls the belt and winds up and rotates the drum when triggered in an emergency.