JPH0452132Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a webbing tensioning device that brings the occupant restraining webbing into close contact with the occupant during a vehicle emergency.

[Problems to be solved by the prior art and the invention] Currently, when a vehicle is normally running, a mainspring spring with a small biasing force biases the webbing in the direction of winding it around the winding shaft, and in case of a vehicle emergency, a large biasing force is applied. A webbing tensioning device has been proposed that uses a mainspring spring to suddenly tension the webbing with a strong force to restrain the occupant.

This webbing tensioning device is equipped with an acceleration sensor to detect when the vehicle is in an emergency state. A pendulum or the like is usually applied to this acceleration sensor.

The pendulum is suspended in a normal driving state of the vehicle and is adapted to be tilted in an emergency state of the vehicle. This tilting of the pendulum rotates the sensor lever, which in turn connects the clutch and activates the webbing tensioning device.

Therefore, it is preferable that the rotation of the sensor lever exerts little resistance against the tilting of the pendulum, but conventionally, the rotation of the sensor lever has been designed to rotate around a pin fixed to the seat, so there is no friction. The force is relatively large and requires an increase in the pendulum mass.

The present invention takes the above-mentioned facts into account, and aims to provide a webbing tensioning device that allows smooth movement of the sensor lever and allows the occupant to be quickly restrained by the webbing in the event of a vehicle emergency.

[Means and effects for solving the problem] The webbing tensioning device according to the present invention biases the winding shaft on which the occupant restraint webbing is wound in the webbing winding direction with the urging force of a small elastic body, and A webbing tensioning device that transmits the biasing force of a large elastic body to a take-up shaft by operating a trigger means and a clutch means to forcibly rotate the take-up shaft in the webbing take-up direction in an emergency; A sensor lever that provides a driving force to the trigger means, a support member that supports the sensor lever, and a sensor lever that is disposed between the sensor lever and the support member, serves as a rotation axis of the sensor lever, and is rotatable relative to the sensor lever. and an elastic body that biases the sensor lever toward the shaft support roller. It is characterized by a small contact area.

Therefore, the contact area of the shaft support roller with the support member becomes smaller, and the frictional resistance is reduced. Therefore, the sensor lever rotates smoothly, and the urging force of the large elastic body can be quickly and reliably transmitted to the winding shaft in the event of a vehicle emergency.

[Embodiment] Figs. 1 to 4 show a webbing retractor 10 in which a webbing tensioning device according to the present invention is integrally incorporated.

A frame 12 of this webbing retractor 10 is fixed to the vehicle body with bolts 14, and a pair of leg plates 16 and 18 extend parallel to each other from both ends thereof.

Both ends of a winding shaft 20 are pivotally supported by the leg plates 16 and 18, and one end of an occupant restraining webbing 22 is locked to an intermediate portion of the winding shaft 20.

Here, when the webbing 22 is stored, the webbing 22 is wound around the winding shaft 20 in layers.

A tongue plate is attached to the other end of the webbing 22, and when this tongue plate engages with a buckle device (both not shown), the occupant is placed in the webbing state.

Incidentally, an inertia lock mechanism is attached to the outside of the leg plate 16, which can sense a vehicle emergency and instantly prevent the rotation of the take-up shaft 20 in the webbing pull-out direction.

A rectangular shaft portion 24 is formed at the end of the winding shaft 20 protruding from the leg plate 18. This rectangular shaft portion 24
is inserted into a rectangular hole 28 formed in the small diameter shaft 26, so that the small diameter shaft 26 rotates coaxially with the winding shaft 20.

A slit 30 is provided at the tip of this small diameter shaft 26, and a small mainspring spring 32 is inserted into this slit 30.
The inner end of is locked. The small mainspring spring 32 is housed in a small case 34, and its outer end is locked to the small case 34.

The small case 34 is fixed to the leg plate 18 via a large case 36 and a seat 38, which are interposed between the small case 34 and the leg plate 18.

As a result, the small mainspring spring 32 is contracted in accordance with the amount by which the webbing 22 that has been wound up in layers around the winding shaft 20 is pulled out, and the winding force is increased. Here, the winding force of the small mainspring spring 32 is weak, and when the occupant wears the webbing 22, the pressure feeling of the webbing 22 on the occupant is extremely small.

A large mainspring spring 40 is housed in the large case 36. The inner end of this large mainspring spring 40 is locked to the cylindrical portion 44 of the actuating ring 42, and the outer end is locked to the large case 36.

A circular hole 46 is provided in the axial center of the actuating ring 42, which is supported by the small diameter shaft 26 and is rotatable relative to the small diameter shaft 26.

Further, the outer circumference of the large diameter portion of the actuation ring 42 is formed smaller than the inner circumference diameter of the large case 36, and a recess 45 is further provided in a part of this outer circumference. Furthermore, an attachment 47 is provided in the gap between the outer circumferential arc-shaped portion excluding the recessed portion 45 and the inner circumference of the large case 36.
is interposed therebetween, and the operating ring 42 is pivotally supported by the large case 36 via this attachment 47.

This attachment 47 is made of resin, has a substantially U-shape along the large-diameter outer periphery of the actuation ring 42, and is fixed to the inner periphery of the large case 36.

This reduces the frictional force generated when the actuating ring 42 rotates, allowing the actuating ring 42 to rotate smoothly.

Here, the large mainspring spring 40 has a larger biasing force than the small mainspring spring 32, and is normally held in a wound state. Here, when the vehicle falls into an emergency state, the trigger means 52 is driven by the operation of the sensor section 50, the state of holding the biasing force of the large mainspring spring 40 is released, and the webbing 22 is moved along with the small mainspring spring 32 to the winding shaft. A biasing force is applied to the winding shaft 20 in the winding direction of the winding shaft 20.

The sensor section 50 includes a pendulum 56 and a sensor lever 58.
The pendulum 56 is an acceleration sensor that operates a sensor lever 58 in case of a vehicle emergency.

As shown in FIGS. 5 and 6, a notch 60 is provided at one end of the sensor lever 58. As shown in FIGS. The notch portion 60 has slopes on both sides of the deepest groove portion having a circular arc shape with a large curvature.

Further, near the other end of the sensor lever 58, an interlocking pin 62 extending in the horizontal direction is attached.

The notch portions 60, 60 have a shaft supporting roller 6.
A part of the outer periphery of the rollers 4 and 64 is accommodated therein, and the sensor lever 58 is rotatable around the supporting rollers 64 and 64.

The shaft support rollers 64, 64 have a main body 64A.
A rotating shaft 64B is formed to protrude from both ends of the rotary shaft 64B.

Further, the other outer peripheries of the supporting rollers 64, 64 are formed in the cutout portions 66A, 66B of the guide member 66 provided at the lower part of the seat 38.
They are accommodated in cutouts 68, 68 having the same shape as those of 0 and 60.

Further, an engagement pin 70 is attached to the outer peripheral surface of the leg plate 66B of the guide member 66, and a tension coil spring 72 is attached between the engagement pin 70 and the interlocking pin 62.

This tension coil spring 72 biases the sensor lever 58 toward the pivot roller 64,
8 is pivoted to a pivot roller 64.

As a result, the sensor lever 58 is moved to the shaft support roller 6.
4, 64, the pivot roller 6
4 and 64 are also designed to rotate relative to each other.

Here, only the outer periphery of the main body 64A of the shaft supporting rollers 64, 64 accommodated in the notches 68, 68 comes into contact with the guide member 66 and the sensor lever 58, thereby providing shaft support. The friction force when the rollers 64, 64 rotate relative to the sensor lever 58 is reduced. Furthermore, the rotating shaft 64
Both end portions of B are in contact with the guide member 66 and the side portions of the sensor lever 58, respectively, to prevent axial movement of the rotating shaft 64B.

In this case, the end surface area of the rotating shaft 64B is small;
Guide member 66 when the shaft support rollers 64, 64 rotate
And the frictional resistance with the sensor lever 58 is relatively small.

As shown in FIG. 2, when the sensor lever 58 is at the lowest position and placed on the pendulum 56 when viewed from the axial direction of the shaft support roller 64, the engagement pin 7
0 and the interlocking pin 62.
2 is disposed below the axis of the supporting roller 64 (in the direction of the pendulum 56), so that the sensor lever 58 is biased clockwise in FIG. 2 and comes into contact with the pendulum 56. has been done.

Here, due to the swinging of the pendulum 56, the sensor lever 5
8 is pressed upward, the axis of the tension coil spring 72 reaches above the axis of the pivot roller 64, and as a result, the tension coil spring 72 conversely supports the sensor lever 58. The rollers 64 are biased counterclockwise in FIG. 2 centering on the rollers 64, 64.

When the sensor lever 58 is rotated in the counterclockwise direction, this rotational force is transmitted to the trigger means 52 disposed above the sensor lever 58.

The trigger means 52 includes a cam 74 and a rotating pawl 76.
It is equipped with

The cam 74 is approximately fan-shaped when viewed from the front in FIG. 80, and is designed to rotate around this pivot pin 80.

In this case, the cam 74 and the sensor lever 58 are
Under normal conditions, it is preferable to provide a slight gap.

Therefore, when the sensor lever 58 rotates, it comes into contact with the lower surface of the cam 74, and this cam 74 moves in conjunction with the sensor lever 58 to move the second shaft around the pivot pin 80.
It is designed to rotate clockwise in the figure.

Further, an approximately L-shaped elongated hole 82 is provided on the end surface of the cam 74 and continues near both ends of the arc, into which an interlocking pin 84 provided at one end of the rotating pole 76 is inserted. ing.

A circular hole 86 is provided at the other end of this rotating pole 76.
is provided and is inserted and pivotally supported by a pivot pin 88 attached to the seat 38.

Here, when the vehicle is in a normal running state, the interlocking pin 84 of the rotating pole 76 is arranged at one end 82A of the elongated hole 82 of the cam 74. When the cam 74 rotates clockwise in FIG. 2, the interlocking pin 84 reaches a bent part in the middle of the elongated hole 82, and after passing through this bent part, it reaches the other end 82B of the elongated hole 82. It's getting old.

Therefore, in this state, the rotating pole 76 is rotated clockwise in FIG. 2 about the pivot pin 88.

The rotary pole 76 is provided with a cutout step from the longitudinally intermediate portion to the distal end, and serves as a stopper 90. This stopper 90 is designed to prevent rotation of the actuating ring 42 in the normal state of the vehicle.

That is, a recess 45 provided in a large diameter portion of the outer periphery of the actuating ring 42 is fitted with the stopper 90, and rotation of the actuating ring 42 is prevented despite the biasing force of the mainspring spring 40.

Note that the friction plate 92 is connected to the circular groove 102.
When storing it in the friction plate 92
What is necessary is to detour the convex portion 104 while elastically deforming a part of the outer periphery of the convex portion 104 .

Here, when the rotating pole 76 rotates downward in accordance with the rotation of the cam 74, the stopper 90
The rotation prevention of the actuating ring 42 by the actuating ring 42 is released and the actuating ring 42 is allowed to rotate.

This rotation of the operating ring 42 causes the clutch means 54 to actuate and prevent the rotation of the operating ring 42 from moving towards the small diameter shaft 2.
6.

The clutch means 54 includes a friction plate 92, a lever 94 and a gear wheel 96.

The friction plate 92 is formed in the shape of a thin disk, and has a circular hole 98 in the shaft center, and the friction plate 92 is formed between the winding shaft 20 and the small diameter shaft 26.
It is coaxially supported.

Moreover, on the outer periphery of the friction plate 92,
Three arms 100 are integrally protruded at equal intervals and are bent toward the seat 38.

These arms 100 are formed by making approximately L-shaped cuts from the outer periphery of the friction plate 92.

A circular groove 102 for accommodating the friction plate 92 is provided at the abutting portion of the seat 38 with the friction plate 92, and serves as one side abutting surface of the friction plate 92. Further, three convex portions 104 extending in the axial direction of the circular groove 102 are formed on the peripheral edge of the circular groove 102 to correspond to the arm 100, and the friction plate 9
It is designed to abut near the outer periphery of the other side of 2.

When the friction plate 92 is brought into contact with this circular groove 102, by arranging the arm 100 between this convex part 104 and the bottom surface of the circular groove 102, and by setting the wall thickness of the convex part 104, Convex portion 10
4 and the bottom surface of the circular groove 102 is set to a predetermined value, so that the frictional force when the friction plate 92 rotates can be kept constant.

On the end face of the friction plate 92, there is a groove 3 that is inclined with respect to the radial direction of the friction plate 92.
One end of the lever 94 is provided with an interlocking pin 108 which is connected to the elongated hole 106.
06 (the part farthest from the circular hole 98) is inserted.

The other end of this lever 94 is shaped like an arc, and a pivot pin 110 is attached to the center of this arc.

This pivot pin 110 is pivotally supported by the operating ring 42, and rotates together with the operating ring 42 when the rotation of the operating ring 42 is released.

Due to this movement of the pivot pin 110, the interlocking pin 1
08 moves toward the inner end along the elongated hole 106, so that the tip of the lever 94 fits into a corrugated portion 112 formed on the outer periphery of the gear wheel 96. .

The gear wheel 96 is coaxially attached to the small diameter shaft 26, so that when the corrugated portion 112 of the gear wheel 96 and the lever 94 are fitted, the biasing force of the large mainspring spring 40 is transmitted to the small diameter shaft 26. It's becoming like that.

The operation of this embodiment will be explained below.

When wearing the occupant webbing 22, the occupant pulls out the webbing 22 wound in layers around the winding shaft 20 of the winding device 10 and puts it on.

In this case, only the biasing force of the small mainspring spring 32 is acting on the webbing 22, so the webbing 22 is in light contact with the occupant. Therefore, the occupant can smoothly change the driving position without feeling pressured.

Here, when the vehicle falls into an emergency state, the pendulum 56, which is an acceleration sensor, vibrates, and the pendulum 56 rotates the sensor lever 58 counterclockwise in FIGS. 2 and 6 around the pivot rollers 64, 64. let

Since the shaft support rollers 64, 64 are supported in the axial direction by the small-diameter rotating shaft 64B, the shaft support rollers 64, 64 are
4 and 64 are prevented from moving along their axes, and the area of contact between the guide member 66 and the side portion of the sensor lever 58 is reduced, so that the frictional resistance during rotation is improved.

Further, the shaft support roller 6
4 and 64 are also designed to rotate relative to each other, so
The rotational friction force of the sensor lever 58 is reduced, and the response of the vehicle in an emergency situation is improved.

The sensor lever 58 is normally biased by a tension coil spring 72 that rotates clockwise in FIGS. When moved by a certain amount, the tension coil spring 72 reverses its biasing direction and sharply pushes the sensor lever 58 upward.

The movement of the sensor lever 58 causes the cam 74 to rotate clockwise in FIG. 2 around the pivot pin 80.

This rotation of the cam 74 causes the pivot pin 80 of the rotary pole 76 to move from one end of the elongated hole 82 (FIG. 2 82A) to the other end (FIG. 2 82B). Along with this movement, the rotating pawl 76 rotates clockwise in FIG.
is rotated by the biasing force of the large mainspring spring 40.

Here, an attachment 47 is interposed between the outer periphery of the operating ring 42 and the inner periphery of the large case 36, and the operating ring 42 is pivotally supported by the attachment 47, so that the frictional force is reduced. The actuation ring 42 rotates smoothly. Furthermore, since the outer circumference of the actuating ring 42 has a smaller diameter than when the outer circumference of the actuating ring 42 directly contacts the inner circumference of the large case 36, the friction rotational torque is smaller.

In accordance with the rotation of the actuation ring 42, the pivot pin 110 of the lever 94 moves, and as a result, the interlocking pin 108, which had been inserted into the outer end of the long hole 106 of the friction plate 92, moves into the long hole 106 of the friction plate 92. 106 , so that the tip of the lever 94 fits into the corrugated portion 112 of the gear wheel 96 .

In the friction plate 92, the arm 100 is disposed between the circular groove 102 and the convex portion 104 and is held by a moderate frictional force, so that when the interlocking pin 108 moves, this frictional force Not rotated.

When the movement of the interlocking pin 108 is completed and the interlocking pin 108 is fitted into the corrugated portion 112, the friction plate 92 receives the rotational force of the actuation ring 42 via the lever 94 and the elongated hole 106. The rotational force of this operating ring 42 is applied to the friction plate 92.
The actuation ring 42 is able to transmit rotational force to the corrugation 112 because it is much greater than the frictional force exerted on the corrugation 112 .

Since the corrugated portion 112 is pivotally attached to the small diameter shaft 26, the biasing force of the large mainspring spring 40 and the biasing force of the small mainspring spring 32 can be transmitted to the winding shaft, and as a result, a large tension is applied to the webbing 22. can be granted.

Also, at the same time as this webbing tension, the leg plate 16
An inertia lock mechanism 23 attached to the outside of the webbing operates to stop the rotation of the take-up shaft 20 in the webbing pulling direction, so that the occupant is tightly restrained.

In this embodiment, the attachment 47 is fixed to the inner circumference of the large case 36, but the attachment 47 is fixed to the inner circumference of the large case 36.
7 rotates relative to the actuation ring 42, similar effects can be obtained.

Further, in this embodiment, the main body 64A of the shaft support roller 64
A small-diameter rotating shaft 64B was formed protruding from the seventh
As shown in the figure, both end surfaces of the shaft support roller 64 are provided with spherical parts 122, and as shown in FIG.
By providing the chamfered portion 124, the same effect can be obtained even if this end portion has a small diameter.

Further, in this embodiment, both ends of the shaft support roller have a small diameter, but the small diameter portion may be formed only at the end that contacts the guide member.

[Effects of the invention] As explained above, the webbing tensioning device according to the invention includes a shaft support roller that is disposed between the sensor lever and the support member, serves as the rotation shaft of the sensor lever, and is rotatable relative to the sensor lever. The end portion of the shaft support roller has a smaller diameter than the middle portion of the shaft support roller, and the contact area with the support member is small, so that the sensor lever can move smoothly and quickly in the event of a vehicle emergency. This has an excellent effect in that the occupant can be restrained by the webbing.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the webbing tensioning device according to this embodiment, Fig. 2 is a sectional view taken along the line of Fig. 1, Fig. 3 is a sectional view taken along the line of Fig. 1, and Fig. 4 is an exploded perspective view of Fig. 1. 5 is a perspective view of the clutch portion, FIG. 6 is a perspective view taken along the line shown in FIG. 10... Webbing tension device, 20... Winding shaft, 22... Webbing, 32... Small mainspring spring, 38... Sheet, 40... Large mainspring spring,
50...Sensor section, 64...Spindle support roller, 64A
...Main body, 64B...Rotating shaft, 66...Guide section.

Claims (1)

[Scope of utility model registration request] The winding shaft on which the occupant restraint webbing is wound is urged in the webbing winding direction by the urging force of a small elastic body,
A webbing tensioning device that transmits the biasing force of a large elastic body to a take-up shaft by operating a trigger means and a clutch means to forcibly rotate the take-up shaft in a webbing take-up direction in the event of a vehicle emergency; a sensor lever that applies a driving force to the trigger means; a support member that supports the sensor lever; and a support member that is disposed between the sensor lever and the support member and serves as a rotation axis of the sensor lever and that rotates relative to the sensor lever. an elastic body that biases the sensor lever toward the shaft support roller, and an end portion of the shaft support roller has a smaller diameter than an intermediate portion of the shaft support roller, and A webbing tensioning device characterized by having a small contact area.