JP2610936B2 - Seat belt retractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] <Industrial application field> The present invention restricts the extension of a seat belt in the event of a collision or the like, and at the same time, winds up a seat belt for automatically tightening the slack. Related to the device.

<Related Art> For example, seats of automobiles are provided with seat belts for restraining occupants from moving forward in order to prevent occupants from being thrown forward in a collision or the like. Retractor device with automatic locking device during tension (hereinafter referred to as ELR) that locks the take-up shaft of the seat belt only at the time of sudden stop or collision without restricting the operation during operation
May be provided.

This type of ELR generally detects the deceleration at the time of collision or sudden extension of the seat belt, and locks the winding shaft in a very short time. If the amount of seat belt slack is large,
It is conceivable that the occupant's binding force becomes insufficient.

In order to tension the seat belt at the time of a collision based on such a viewpoint, a rotating member that rotates by a driving force applied from a driving device activated by a collision detection device that detects that a predetermined deceleration has acted, When the rotating member rotates, one end abuts on the seat belt and the movable member pivotally supported by the rotating member so as to be tilted by the reaction force of the seat belt at that time, and the other end of the movable member when tilted. It consists of a fixing member that sandwiches and clamps the seat belt,
A preloader device that clamps a portion of the seatbelt extended from the ELR device when a collision is detected, and wraps a portion of the seatbelt ahead of the clamped portion around a movable member and draws the seatbelt toward the ELR device is disclosed in Japanese Patent Application No. 1986-
The applicant has proposed in the specification of 303155.

<Problems to be solved by the invention> According to the above-described device, although sufficient tension can be applied to the seatbelt regardless of the state of the ELR device, it is necessary to achieve a sufficient retraction amount of the seatbelt. In addition, it is necessary to increase the outer peripheral length of the movable member around which the seat belt is wound. Increasing this inevitably increases the radius dimension of the movable member and increases the inertial weight. Therefore, a relatively large output is required to start the rotating member pivotally supporting the tilting member with high responsiveness. Had to be enlarged.

The present invention has been made in view of such problems of the related art, and a main object of the present invention is to provide a seat belt retractor that does not require an increase in the size of a driving device.

[Constitution of the Invention] <Means for Solving the Problems> According to the present invention, the object of the present invention is to allow the seat belt to be freely fed and wound up in a normal state, and that the seat belt can be freely retracted in a predetermined deceleration state. A retractor device that can limit feeding, a collision detection device that detects that a predetermined deceleration has acted, a drive device that is activated by the collision detection device, and a rotation that is rotated by a driving force provided by the drive device A movable member pivotally supported by the rotating member such that one end abuts on the seat belt when the rotating member rotates and tilts due to a reaction force of the seat belt at that time, and the other end of the movable member when tilting And a fixing member that clamps the seat belt by clamping the seat belt. When a collision is detected, a portion of the seat belt extended from the retractor device is clamped. A retractor that winds a portion of the seatbelt ahead of the clamped portion around the movable member and retracts the retractable device toward the retractor device, and the retractor device and the retractor device are mounted on the seatbelt. The driving device and the collision detecting device are formed integrally with each other along the axis, and the movable member is radially protruded from a tilting center thereof. This is achieved by providing a seatbelt winding device characterized by having a plurality of ridges.

<Operation> In this way, the seat belt is pulled in a leverage manner by the rotating movable member, so that a large stroke can be given to the seat belt with a relatively small output and a small space, and furthermore, the seat belt protrudes radially. Since the seat belt is supported and wrapped around the projecting edges of the plurality of ridges, it is possible to minimize the thickness of the movable member while ensuring a sufficient amount of seat belt retraction.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a configuration around a seat belt to which the present invention is applied. A seat belt 3 pulled out upward from a seat belt retractor 2 fixed to a lower portion of a center pillar 1 in a vehicle interior is a center belt. After passing through a three ring 4 attached above the pillar 1, it extends downward and has an end 6 attached to the rear side surface of the seat 5. A tongue plate 7 is provided between the through ring 4 and the end 6 of the seat belt 3 so as to be movable along the seat belt 3.

The occupant seated on the seat 5 is driven by the seat belt retractor 2.
After the seat belt 3 is pulled out from the occupant, the tongue plate 7 is connected to the buckle 8 attached to the side of the seat opposite to the fixing point of the seat belt end portion 6 so as to cover the occupant's shoulder, chest, and waist. The seat belt 3 is hung.

As shown in FIGS. 2 to 4, the seat belt retractor 2
Are an ELR device 9 for winding and unwinding the seat belt 3 during normal use, a winding device 10 for tightening the looseness of the seat belt 3 at the time of collision, and a drive for applying a rotational force to the winding device 10. The apparatus includes a device 11 and a deceleration sensor 12 for detecting a collision.

The ELR device 9 applies a rewinding rotational force to the webbing drum that winds up the seat belt 3 by a built-in spring means in the same manner as in the known type, and at the same time, when suddenly decelerating or when the feeding speed of the seat belt is adjusted to a predetermined value. When the value exceeds the value, the ratchet mechanism can prevent the seat belt 3 from being extended.

The casing 13 of the winding device 10 is formed by bending a metal plate.
A pulley 15 is rotatably supported on one side wall of the ELR device 9 via a bearing 14 made of a self-lubricating synthetic resin material. The pulley 15 has a wire connected to the drive device 11 at one end and the other end fixed to an appropriate position of the pulley 15.
16 are wound.

By the way, the drive device 11 includes a cylinder 17 extending in a tangential direction of the pulley 15 and a piston sliding in the cylinder 17.
It comprises a propellant 19 and a propellant 19 contained in the base of a cylinder 17 for applying a propulsive force to the piston 18, and is fixed to the upper end of the casing 13 of the winding device 10. And cylinder
The propellant 19 is ignited and exploded by the action of the deceleration sensor 12 fixed integrally to the base of 17, and the wire 16 is pulled by the piston 18 that slides linearly at the combustion pressure at this time, thereby The pulley 15 is driven to rotate.

The casing 13 has an opening 20 on the other side wall so as to surround a ratchet wheel described later. A ratchet wheel 21 is rotatably received inside the opening 20.

Between the opposing surfaces of the pulley 15 and the ratchet wheel 21, the pulley 15 and the ratchet wheel 21 are connected to each other at a position slightly outside the center of the pulley 15 so as to form a substantially oval cross section. The clamp cam 22 is stretched.

A movable clamp cam 23 is rotatably sandwiched between the pulley 15 and the ratchet wheel 21 at a position facing the fixed clamp cam 22. The movable clamp cam 23 has three ridges 24a, 24b, and 24c that protrude substantially radially from the center of the rotation shaft 23a and extend in the axial direction.

In the initial state, a gap communicating in the vertical direction is provided between the opposed surfaces of the fixed and movable clamp cams 22 and 23.
25 is formed for passing a seat belt (not shown). A plurality of clamp grooves 26 having substantially complementary shapes over substantially the entire length along the axial direction are provided on the opposing surfaces of the two clamp cams 22 and 23 on the belt entrance side of the gap 25.
a and 26b are formed.

On the outer periphery of the ratchet wheel 21 over a substantially 3/4 circumference, saw-tooth-shaped external ratchets 27 inclined rearward with respect to the normal rotation direction are arranged in line. An internal tooth ratchet 28 having a shape complementary to the above-mentioned external tooth ratchet 27 is arranged in a row on the inner periphery of the opening 20 over a substantially 5/8 circumference.

The opening 20 and the ratchet wheel 21 are arranged such that, when they are placed coaxially with each other, the vertices of the external tooth ratchet 27 and the internal tooth ratchet 28 are slightly in contact with each other or are relatively rotatable without contact. , Its inner diameter and outer diameter are defined.

5 and 6 show the deceleration sensor 12 in detail.

On both side surfaces of the sensor body 32 of the deceleration sensor 12, a pair of pendulums 33a and 33b serving as sensor weights are hung so as to be swingable with their upper ends serving as fulcrums. These pendulums 33a and 33b form a U-shaped cross section with an open upper side, are combined in an inner and outer double, and are supported by support shafts 34a and 34b arranged in parallel with each other. It can swing independently without interfering with the movement of the opponent.

A cylinder is provided at an intermediate portion of the sensor body 32 between the two pendulums 33a and 33b so as to communicate between both side surfaces 32a and 32b of the sensor body 32 along a tangential direction to the swing locus of the two pendulums 33a and 33b. A guide hole 34 having a shape is formed.

The guide hole 34 is provided with a spring receiver 35 in an opening on one end face 32a side.
And a firing pin for igniting the primer 19 of the propellant 19.
36 is inserted inside it. This firing pin 36 has a point 36
a and a plunger 3 having a bottomed cylindrical shape that slides into the guide hole 34
6b, the guide hole is formed by a small-diameter first coil spring 37 contracted in the plunger 36b and a large-diameter second coil spring 38 contracted between the end of the plunger 36b and the spring receiver 35. The spring 34 is constantly urged toward the opening on the other end surface 32b side.

As shown in FIG. 7, a trigger arm 39 is pivotally supported between the sensor body 32 and the inner surface of the pendulum 33b so as to be swingable in a seesaw manner. The trigger arm 39 has a substantially crank shape in a side view (FIG. 5) and a substantially U-shape in a front view (FIG. 6). The upper open end 39a protrudes into the guide hole 34, and the The open end 39a engages with an engaging portion 36c formed in the plunger 36b.

The trigger arm 39 is pivotally supported at a bent portion near the open end 39a, and a support shaft for supporting the trigger arm 39 is provided.
The reference numeral 40 penetrates both side surfaces of the pendulums 33a and 33b, and then protrudes into a guide groove 41 formed in the sensor body 32 in a vertical direction. Thus, the support shaft 40 can be displaced only in the vertical direction along the guide groove 41.

On both sides of the pendulums 33a and 33b, through holes 42a and 42b are formed to insert both ends of the support shaft 40, respectively. The through hole 4 opened in the outer pendulum 33a of the through holes 42a and 42b
2a, a locking portion 43 is provided to define the vertical position of the support shaft 40, and is expanded rearward from the locking portion 43 and downward from immediately after the locking portion 43. The pendulum 33a can be displaced forward by releasing the locked state with the support shaft 40, and the support shaft 40 detached from the locking portion 43 can be displaced downward.

On the other hand, the through-hole 42b formed in the inner pendulum 33b is used to support the support shaft 40 when it is locked by the locking portion 43 of the outer pendulum 33a.
It is expanded rearward and downward with reference to the position of
The inner pendulum 33b can be displaced forward without being hindered by the support shaft 40, and the downward displacement of the support shaft 40 is not hindered.

As shown in FIG. 8, a protruding piece 44 is provided at the rear edge of the bottom of the inner pendulum 33b to engage with the bottom of a U-shaped end 39b formed on the rear end of the trigger arm 39. Have been. The trigger arm 39 is engaged with the firing pin 36 in a state where the support shaft 40 is locked to the locking portion 43 of the outer pendulum 33a and the U-shaped end 39b is engaged with the projection 44 of the inner pendulum 33b. By engaging the open end 39a with the mating portion 36c, the firing pin 36 is held stationary against the urging forces of the first and second coil springs 37 and 38.

At the front end on the bottom side of both pendulums 33a and 33b, projections 45a and 4
5b are respectively formed. And these projections 45a ・ 4
Inside the sensor body 32 facing 5b, bias springs 46a and 46b are contracted in a direction parallel to the axis of the guide hole 34, respectively. These bias springs 46a and 46b are connected to both pendulums 33a and 33b via guide caps 47a and 47b, respectively.
Abuts the projections 44a and 45b of the
33a and 33b are constantly urged backward. In this manner, the engagement between the rear projection 44 of the inner pendulum 33b and the U-shaped end 39b of the trigger arm 39, and the engagement between the locking portion 43 of the outer pendulum 33a and the end of the support shaft 40 of the trigger arm 39. Engagement is always maintained.

Next, the manner of operation of the device of the present invention shown in the above embodiment will be described with reference to FIGS. 9 to 19.

In a normal running state, the two pendulums of the deceleration sensor 12 are used.
Moment of inertia acting on 33a / 33b and bias spring 46a
The biasing force of 43b is set so as to hang, and as shown in FIGS. 9 and 11, the guide force is engaged with the guide groove 41 of the sensor body 32 and the locking portion 43 of the outer pendulum 33a. Since the rotation of the trigger arm 39 is prevented, the firing pin 36 is prevented from moving at the open end 39a of the trigger arm 39.

On the other hand, the seat belt retractor 2 is normally in the state shown in FIG. 13, and the seat belt 3 can be freely fed and wound through a gap 25 between the fixed clamp cam 22 and the movable clamp cam 23. . In order to maintain this position, the side surface of the ratchet wheel 21 is covered with a resin cover 30 provided with a projection 29 that engages with the ratchet wheel 21. The projection 29 is easily broken by the torque when the drive device 11 is operated.

Now, when the vehicle collides and a deceleration equal to or more than a predetermined value acts in the traveling direction, the bias spring 46a
The pendulums 33a and 33b of the deceleration sensor 12 tilt so as to overcome the urging force of 46b and swing the lower end portion forward. As a result, the U-shaped end 39a of the trigger arm 39 comes off the projection 44 of the inner pendulum 33b. Then, the binding force acting on the firing pin 36 is released, and the first and second coil springs 37 are released.
The firing pin 36 is ejected toward the primer F by pushing away the open end 39a of the trigger arm 39 by the resilience given from 38 (FIG. 12).

Further, the trigger arm 3 is moved from the locking portion 43 of the outer pendulum 33a.
When the support shaft 40 of 9 is disengaged, the open end 39a of the trigger arm 39 is displaced downward together with the support shaft 40, and the restraining force acting on the firing pin 36 is released in the same manner as described above. Coil spring
The resilient force given by 37 and 38 pushes the open end 39a of the trigger arm 39 to eject the firing pin 36 toward the primer F (FIG. 10).

In this way, when one of the pendulums tilts, the firing pin 36 operates.

When the tip 36a of the firing pin 36 strikes the primer F, the propellant 19 is ignited, and the piston 18 is pushed up by the explosion pressure at this time.

When the piston 18 is actuated, the wire 16 is pulled in the direction of arrow P in FIG. 3, and the ratchet wheel 21 rotates together with the pulley 15 in the direction of arrow B in FIG.

Then, the protrusion 24a of the movable clamp cam 23 strikes the seat belt 3. As a result, the movable clamp cam 23
While pressing the seat belt 3 as shown in FIG.
To seat the seat belt 3 between the clamp grooves 26a and 26b.

Further, when the movable clamp cam 23 rotates together with the pulley 15, the movable clamp cam 23 acts as a "lever" with the rotation shaft 23a as a fulcrum and the end of the ridge 24a as a point of action.
As shown in FIG. 15, the seat belt 3 is pulled in the direction of arrow D.

In this process, since the rotation torque of the driving device 11 is larger than the tension applied to the seat belt 3,
The ratchet wheel 21 tends to be pulled downward rather, and the external tooth ratchet 27 and the internal tooth ratchet 28 slide with each other, and the winding device 10 rotates.

The wire 16 is further pulled, and the protrusion of the fixed clamp cam 22 is formed.
24a and 24b further retract the seat belt 3 (FIG. 16).

When the wire 16 is almost completely retracted and the rotational torque acting on the pulley 15 and the ratchet wheel 21 disappears, the reversely directed torque acts on the ratchet wheel 21 while pulling up slightly outward due to the tension of the seat belt 3. (Figure 17). Then the internal ratchet 28 located almost at the top
The external tooth ratchet 27T closest to T is engaged.

As a result, the turning moment M acts on the ratchet wheel 21 with the first engagement point as a fulcrum (FIG. 18). Then, as shown in FIG. 19, the external tooth ratchet 27 in the range E on the front side in the normal rotation direction from the above-described point.
Engage with the internal ratchets 28, respectively, and prevent the reverse rotation of the winding device 10.

<Effects of the Invention> As described above, according to the present invention, the inertial weight of the movable member (movable clamp cam) can be minimized, so that the driving force for overcoming the inertia moment and starting the winding device is relatively large. The required response can be obtained without increasing the size of the driving device.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram around a seat belt to which the present invention is applied. FIG. 2 is a front view showing the seat belt retractor partially cut away, FIG. 3 is a right side view thereof, and FIG. 4 is a left side view thereof. FIG. 5 is a side view showing an embodiment of the deceleration sensor, partially cut away, and FIG. 6 is a front view of the same. 7 and 8 are transparent perspective views showing only the main parts. 9 to 12 are explanatory diagrams showing the operation state of the deceleration sensor. FIG. 13 is a partial sectional view taken along line XIII-XIII in FIG. 14 to 16 are explanatory views showing a winding process of the seat belt, and FIGS. 17 to 19 are explanatory views showing an operating process of the reverse rotation preventing device. DESCRIPTION OF SYMBOLS 1 ... Center pillar, 2 ... Seat belt winding device 3 ... Seat belt, 4 ... Thru ring 5 ... Seat, 6 ... End 7 ... Tang plate, 8 ... Buckle 9 ... ELR device , 10… Entrainment device 11… Drive device 12… Deceleration sensor 13… Casing, 14… Bearing 15… Pulley 16… Wire 17… Cylinder 18… Piston 19… Medicine, 20 opening 21 ratchet wheel 22 fixed clamp cam 23 movable clamp cam 24a / 24b / 24c ridge 25 gap 26a / 26b clamp groove 27 external ratchet 28 ... Internal ratchet 29 ... Projection, 30 ... Resin cover 32 ... Sensor body 32a / 32b ... End face, 33a / 33b ... Pendulum 34 ... Guide hole, 34a / 34b ... Support shaft 35 ... Spring receiver, 36 ... Striking pin 36a ... Point, 36b ... Plunger 36c ... Engaging part, 37 ... First coil sleeve 38: Second coil spring, 39: Trigger arm 39a: Open end, 39b: U-shaped end 40: Support shaft, 41: Guide groove 42a / 42b: Through hole, 43: Lock Part 44: Projecting piece, 45a / 45b ... Protrusion 46a / 46b ... Bias spring 47a / 47b ... Guide cap

Claims (1)

(57) [Claims] 1. A retractor device capable of freely extending and retracting a seat belt in normal times and restricting the extension of the seat belt in a predetermined deceleration state, and a collision detecting that a predetermined deceleration is applied. Detecting means, driving means activated by the collision detecting means, a rotating member which is rotated by a driving force given by the driving means, one end of which abuts on the seat belt when the rotating member rotates, and the seat at that time A movable member pivotally supported by the rotating member so as to be tilted by the reaction force of the belt; and a fixed member which clamps the seat belt by clamping the seat belt between the movable member and the other end of the movable member at the time of tilt. Upon detection, the movable portion clamps a portion of the seat belt extended from the retractor device, and clamps a portion of the seat belt ahead of the clamped portion to the movable member. A retractor that is wound around and retracted to the retractor device side, the retractor device and the retractor are provided adjacent to each other along the seat belt, and the drive device and the collision detection device Wherein the movable member has a plurality of ridges projecting radially from the tilting center thereof. apparatus.