JPS5881052A - Webbing wind-up apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a webbing retractor used in a seat belt device for protecting occupants in vehicle emergencies, and in particular, the present invention relates to a webbing retractor that is designed to reduce the retracting force after the webbing is attached. The webbing take-up device is designed to wind one end of the webbing for occupant restraint onto the take-up shaft using the biasing force of an elastic body, and the biasing force of the elastic body brings the webbing into close contact with the occupant and also releases the webbing from the occupant. After that, the webbing is wound up on the winding device and scattered inside the car, giving a feeling of pressure to the occupants, causing fatigue and causing problems that lead to a decrease in the webbing attachment rate.

Conventionally, a webbing retractor has been proposed that automatically reduces the webbing tension after the occupant puts on the webbing.In this webbing retractor, a pair of elastic bodies are arranged in series to allow the occupant to attach the webbing. After that, the pair of elastic body connecting parts are fixed and only the biasing force of one of the elastic bodies is applied to the webbing, but the control is complicated and the amount of winding force reduction is immeasurable. there were.

The present invention has been made in consideration of the above facts, and an object of the present invention is to provide a webbing take-up device that can reliably obtain the desired webbing tension reduction state a despite using a single elastic body.

In the webbing retractor according to the present invention, after the occupant wears the webbing, the control device or the return device moves the elastic body by a predetermined amount in the direction of loosening, thereby reducing the feeling of pressure exerted on the occupant.

After the webbing is released, the return device moves the elastic body by the same amount in the direction of increasing the biasing force and winds up the webbing.

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

In the webbing retractor 10 shown in FIGS. 1 to 3, a frame 12 is fixed to a vehicle body 16 by a mounting port 14. As shown in FIG.

A pair of leg plates 18 and 20 extend parallel to each other from both sides of the frame 12, and the vicinity of both ends of the winding shaft 22 are pivotally supported. One end of an occupant restraining webbing 24 is attached to the take-up shaft 22, and a tongue plate 26 shown in FIG. 4 is attached to the other end of the webbing 24.

The occupant can attach the intermediate portion of the webbing 24 by engaging the buckle device a2B attached to the tongue plate 26f to the vehicle body. In addition, the buckle is shown in Figure 3! The tongue plate engagement structure of No. 128 is not shown.

The winding shaft 22 has a base 30 fixed to the outside of the leg plate 20.
The mainspring spring 36 is pivotally supported on the leg plate 20 via a cylindrical portion 32 protruding from the inner end thereof, and the inner end of the mainspring spring 36 is locked to a small diameter portion 34 connected to the end of the winding shaft 22. . This mainspring spring 36 is housed in a spring case 38, and its outer end is locked to the inner periphery of the spring case 38.

The small diameter portion 40 of the spring case 38J is loosely fitted onto the small diameter portion 34 of the winding shaft 22, and is rotatable around the small diameter portion 34 of the winding shaft 22. Further, the small diameter portion 40 is prevented from moving in the axial direction by a screw '42 soldered to the small diameter portion 34 of the winding shaft.

Furthermore, a sheet 44 is interposed between the mainspring spring 36 and the base 30 to reduce the frictional resistance of the mainspring spring.

The spring case 38 has a gear 46 on its outer periphery, and this gear 46 is connected to the cover 4 erected from around the base 30.
It is approaching the inner peripheral surface of 8.

The female part I of the gear 46 corresponds to the solenoid 52 through a notch 50 formed in the bar 48. This solenoid 52 is fixed to the leg plate 18.20)/ZL54
The pin 56 passes through the notch 50 and can come into contact with and separate from the gear 46.

In a normal state, the pin 56 engages with the gear 46 by the biasing force of an elastic body built into the solenoid 52, and has the role of a brake to stop the rotation of the gear 46.

The solenoid 52 is connected to a microcomputer 58 as a control device shown in FIG.
This configuration allows the spring case 38 to rotate while being separated from each other.

Therefore, the spring case 38 supports the reaction force of the biasing force of the mainspring spring 36 with the pin 56 meshing with the gear 46,
Winding shaft 22 winding direction (direction to the arrow in Figure 2)
It is designed to exert the force of

A solenoid 52 is connected to the winding shaft 22 on the outside of the leg plate 20.
A binion 6o is arranged on the opposite side. This pinion 6o meshes with the gear 46 through a notch 62 formed in the cover 48. Also, this binion 60 is the leg plate 2o
Output shaft 66 of motor 64 as a return device fixed to
It is fixed to and receives the rotational force of the motor 64.

The motor 64 receives a signal from the microcomputer 58 and is energized after the occupant wears the webbing. The state of the passenger's webbing is determined by the buckle device i.
This is a configuration in which detection is performed by connecting a buckle switch 70 provided in 28 to a microcomputer 58. That is, the buckle switch 70 connects the movable contact 72 to the fixed contact 74 when the tongue plate 26 is pulled out, that is, when the occupant is not wearing the webbing, and when the occupant wears the webbing, that is, when the tongue plate is not attached. 26 is engaged with the buckle device 28, it comes into contact with either the movable contact 72 or the fixed contact 76, and informs the microcomputer 58 of the occupant's webbing valve device M-u and its mounting state, respectively.

The microcomputer 58 is connected to a rotation detection device 84 fixed to the outside of the leg plate 18, and this rotation detection device detects the rotation of the take-up shaft when the webbing is attached with the webbing fully wound. The position and the position of the winding shaft 22 when the webbing is attached are detected.

To be more specific, the rotation detection device 84 detects the winding shaft 22 and the rotation contact 8.
6 is attached, and around this rotating contact 86, a plurality of strips 88 are provided in parallel with the axis of the winding shaft and are electrically connected to each other. These strips 88 are arranged at equal intervals on the same radius from the axis of the winding shaft, and are arranged at contact points 90.9.
It corresponds to 2.

These contacts 90,92 have their bases connected to the rotor cover 9.
4 and is connected to the microcomputer 58, and the protrusion 96 provided at the tip is connected to the strip 8.
If the protrusion 96 is placed between the strips 88, a signal is sent to the microcomputer 58 indicating a conductive state, and if the protrusion 96 is placed between the strips 88, a cutoff state is sent to the microcomputer 58, and the central processing unit f( cpu) sBB adds the cutoff and conduction states and stores the winding shaft rotation speed in the storage device 58A.
It is designed to be stored in the memory.

When the memory device in the microcomputer 58 [58A and central processing bag [58B] receives a signal from the buckle switch 70 when the occupant wears the webbing, the number of revolutions of the winding shaft 22 from the fully wound state to the webbing mounted state is calculated. and transmits a signal to motor 64 to rotate spring case 38 toward the slack square at a predetermined rate. This ratio can be set as a constant ratio to the number of rotations of the winding shaft from the fully wound state to the webbing shelled state, or the number of revolutions in the loosening direction is increased in proportion to the number of revolutions of the winding shaft to apply to the webbing after loosening. The winding force can always be set to -★ regardless of the physique of the occupant.

After the spring case 38 rotates in the direction of loosening, the solenoid 52f operates to stop the rotation of the spring case 38''. The take-up force increases in accordance with the situation, but when the original driving position is returned, the take-up force is reduced again.In this case, the pulled-out webbing is not retracted securely and the occupant returns to the original driving position. To prevent the risk of the webbing being bent after returning to its original position and creating a gap between the webbing and the occupant, the microcomputer 58 calculates the rotation detection value [8].
It is also possible to send a signal to temporarily rotate the spring case 38 in the direction of increasing the biasing force by detecting the rotation of the webbing drawn out in step 4.

A ratchet wheel 98 is fixed to the winding shaft 22 as shown in FIG. 1, and corresponds to the bowl 100 which is pivotally supported on the leg plate 18. This bowl 100 has a pendulum 1,
02, and when the pendulum 102 tilts in the event of a vehicle emergency, it engages with the ratchet wheel 98 and stops the webbing pull-out of the winding shaft 22. The pendulum 102 is placed on a bracket 104 protruding from the leg plate 18.

The operation of this embodiment configured in this way will be explained. After getting on the vehicle, the occupant pulls out the webbing 24 from the winding device [110] and engages the tongue plate 26 with the buckle device a28, thereby putting the webbing in the webbing-attached state.

At this point, the winding force is F1 in FIG. 6, and the amount of webbing pulled out is D.

Upon receiving the signal from the buckle switch 70 of the buckle device 2all, the microcomputer 58 drives the motor 64f to rotate the spring case 38f by a predetermined amount in the loosening direction, so that the winding force is shown in FIG. The FR is the same as if only the straw R were wound up, and the feeling of pressure on the occupant is reduced.

As mentioned above, this stroke R can be a constant ratio to the drawer fID, or can be increased as the drawer ilD increases, and the winding force after loosening is always constant (for example, (Fll).

When the vehicle is in an emergency situation such as a collision, the pendulum 02 engages the bowl 100 with the ratchet wheel 98, so the webbing of the winding shaft 22 is attached and the direction rotation is stopped, and the occupant is securely restrained by the webbing 24. You can ensure safety.

When the passenger pulls out the tongue plate 26 from the buckle device 28 to release the webbing 24, the microcomputer 58 activates the solenoid 52 to close the pin 5.
6 is spaced apart from the tooth 46 to enable the spring case 38 to rotate. At the same time, the microcomputer 58 sends a signal to the motor 64 to rotate the spring case 38 in the direction of increasing the biasing force by the same amount as the stored movement amount in the loosening direction.
The webbing is wound up to its full length and the winding force is Fo.

In order to quickly wind up the webbing after the occupant releases the webbing, the microcomputer 58 may send a signal to the motor 64 to temporarily increase the winding force of the winding shaft 22 by 4 from the winding force in the fully wound state. can.

Next, FIGS. 7 to 10 show a second embodiment of the present invention, which is another embodiment of the rotation detection device.

In this embodiment, the winding force 22 pinion 106 is fixed and meshes with a reduction gear 108 pivotally supported on the leg plate. The reduction gear 108 meshes with an internal gear *110 on the opposite side of the pinion 106, and this internal gear 110 is coaxially supported with the winding shaft 22. Therefore, the rotation of the °C winding shaft 22 is transmitted to the inner 1iifllO after being decelerated.

On the outer periphery of the internal gear 110, there is a U shown in FIG. 9.1o.
A letter-shaped rotating contact 112 is pasted.

This U-shaped rotating contact 112 is an electrically conductive thin film, and for example, a carbon sheet can be used.

This U-shaped rotating contact 112 is connected to the protrusion 96 of the contact 90.92.
The rotary contact 112 connects the contacts 90 and 92. As the winding shaft rotates, the length L of the contacts 90.92 and the electrically conducting rotating contact 112 changes, so that the rotational speed of the winding shaft 22 is detected and stored in the microcomputer's storage device. C: It has become.

According to this example, the direction of change in the resistance value differs depending on whether the winding shaft is rotated for winding or pulling out, so the direction of rotation of the winding shaft can be easily detected.

In addition to the embodiments described above, various detection devices for detecting the rotational speed of the winding shaft can be applied. Furthermore, the present invention is not limited to the structure for detecting the rotational speed of the winding shaft, but can also detect the winding shaft position e1t when the webbing is attached by detecting the webbing tension.

In addition, in the above embodiment, a solenoid is used to stop the rotation of the splash case under normal conditions, but the motor
(7) There is no need to use a solenoid as long as it has sufficient braking force to prevent rotation of the spring case when stopped. Note that instead of the rotation detecting device of the above embodiment, it is also possible to use a tension detecting device that detects the tension of the webbing pulled out from the take-up shaft.

As explained above, in the webbing retractor according to the present invention, after the occupant has attached the webbing, the control device operates the return device ll to move the elastic body by a predetermined amount in the loosening direction, so that the webbing retractor is a single elastic body. However, it has an excellent effect of being able to reliably obtain a desired winding force reduction state.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the webbing retractor according to the present invention, Fig. 2 is a right side view of Fig. 1, Fig. 3 is a left side view of Fig. 1, and Fig. 4 is a microcomputer wiring connection. A wiring diagram showing the state, FIG. 5 is an exploded perspective view showing the rotation detection device, FIG. 6 is a diagram showing the relationship between the pull-out stroke and webbing winding force, and FIG. 7 is according to the second embodiment of the present invention. A sectional view showing the rotation detection device, Fig. 8 is a sectional view taken along the line ■-■ in Fig. 7, and Fig. 9
The figure is a perspective view showing the internal gear wheel, and FIG. 10 is a developed view of the U-shaped rotating contact. 10... Webbing winding device, 22... Winding shaft, 2
4... Webbing, 28... Buckle device, 38...
... Splash case, 52... Solenoid, 58... Microcomputer, 64... Motor, 70... Buckle switch, 84... Rotation detection bag [1,112...
...U-shaped rotating contact. Agent Patent Attorney Atsushi Nakajima Figure 2 30 Figure 4 l7fS5t'? 1 Drawer stroke Fig. 7 Fig. 8

Claims (4)

[Claims] (1) A take-up shaft to which one end of the occupant restraint webbing is attached, an elastic body that biases the take-up shaft in the webbing take-up direction, and a mechanism that moves the elastic body in a loosening direction to loosen the webbing after the occupant has attached the webbing. A return device that reduces the acting winding force, and a return device (7) that controls the loosening t of the elastic body to a predetermined value that has been predetermined, and returns the webbing by an amount equal to the amount of loosening after uninstalling the webbing. and a control device for moving the elastic body in a direction of increasing the biasing force of the elastic body. (2) The webbing take-up device according to claim 1, wherein the return device moves the elastic body in the return direction by the driving force of a motor. (3) The webbing according to claim 1 or 2, wherein a mainspring spring housed in a spring case is used as the elastic body, and the spring case is rotated by a return device. Winding device. (4) The control device detects the number of rotations of the take-up shaft from a state in which the webbing is fully wound to a state in which the webbing is attached, and rotates the spring case in the loosening direction by a predetermined percentage of this number of rotations. The webbing take-up device according to item 3.