JPH0355471Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a webbing retractor for retracting occupant restraining webbing used in a seat belt device for restraining an occupant in a vehicle emergency.

[Prior Art] A seat belt device is equipped with a webbing retractor for retracting webbing for restraining an occupant, and is designed to ensure the ability of the webbing to follow the occupant when the webbing is attached. It is common for there to be.

This webbing take-up device has various structures such as a so-called normal type, constant torque type, tension reducer type, and tension reliever type. One example is proposed in Utility Model Application Publication No. 51-66925.

By the way, when the webbing is put on or taken off in a cold region, the webbing may become loose while the webbing is being put on, or the webbing may not be wound up properly when the webbing is taken off. This is because at low temperatures, the frictional force between each part becomes larger than at room temperature, so the winding force required to wind up the webbing increases. Winding force that contributes to followability of
That is, as shown in the graph (graph illustrating changes in tension applied to the webbing attachment part), this is because the winding force that contributes to the ability of the webbing to follow the occupant is reduced.

From this, it is conceivable to set the webbing winding force applied to the webbing in advance to a strength suitable for cold regions.

However, if the webbing winding force is set to a strength suitable for cold regions, it is possible to prevent webbing failures when removing the webbing regardless of whether it is in cold or warm regions; Since the winding force that contributes to the ability of the webbing to follow the occupant increases as the webbing rises, there is a problem in that the occupant may feel pressure when wearing the webbing when moving from a cold region to a warm region.

[Problems to be solved by the invention] Taking the above facts into consideration, the present invention is capable of preventing webbing failure due to temperature changes, and is capable of obtaining an appropriate webbing wearing state regardless of temperature changes. It is an object of the present invention to provide a webbing retractor for a seat belt device that can be used as a webbing retractor for a seat belt device.

[Means for Solving the Problems] In the present invention, in a webbing retractor for a seat belt device in which a take-up shaft is rotated by a biasing means to wind up the webbing, a first bias to rotate the take-up shaft is provided. a second means for rotating the take-up shaft;
and the first urging means or the second urging means such that the rotational force of the winding shaft is weaker when the vehicle interior temperature is above a predetermined temperature than when it is below a predetermined temperature.
It is characterized by comprising a control means for preventing the urging force of either one of the urging means from being applied to the winding shaft.

[Function] In the present invention having the above configuration, the control means controls the first urging means or the second urging means so that when the vehicle interior temperature is normal temperature, the rotational force of the winding shaft is weaker than when the temperature is below a predetermined temperature. The biasing force of either one of the biasing means is prevented from being applied to the winding shaft. Therefore, when the vehicle interior temperature is room temperature, the take-up shaft can take up the webbing with a weak rotational force, and the occupant does not feel pressured by the webbing.

On the other hand, when the temperature inside the vehicle decreases, the frictional force and resistance force of each part of the winding device increases, but when the temperature inside the vehicle falls below a predetermined temperature, the first The control means that prevents either the urging force of the urging means or the second urging means from being applied to the winding shaft releases the blocking state, so that the winding shaft is heated to a temperature higher than a predetermined temperature. A stronger biasing force is applied compared to the case of , and it is possible to resist the increased frictional force and resistance force. Therefore, when the temperature inside the vehicle becomes low, the winding shaft is rotated against the increased frictional force and resistance force, so there is no problem in winding the webbing at low temperatures, and even at room temperature. You can wind up the webbing in the same way. Therefore, the occupant can wear the webbing appropriately regardless of temperature changes.

[Embodiment] FIGS. 1 to 4 show an embodiment of a webbing retractor for a seat belt device according to the present invention. FIG. 4 shows a seat belt device to which an embodiment of the present invention is applied.

As shown in FIG. 4, in this seatbelt device, the webbing retractor 10 is attached to the center pillar 1
The webbing 14 pulled out from the webbing retractor 10 passes sequentially through a slip joint 16 attached to the upper part of the center pillar 12 and an opening in a tongue plate 18. It is locked to an anchor plate 20 attached to the lower part of. The tongue plate 18 can be engaged with a buckle device 22 provided upright in the center of the vehicle.

The webbing retractor 10 has a frame 24 fixed to the center pillar 12 by bolts (not shown), and the frame 24 is fixed to the center pillar 12 by bolts (not shown).
Leg plates 26, 2 provided parallel to each other on both sides of 5
Both ends of the winding shaft 28 are pivotally supported by the winding shaft 6A.

The webbing 14 is located in the middle of the winding shaft 28.
One end of is locked. As a result, the webbing 14 is wound up in layers by rotating the take-up shaft 28 (in the direction of arrow A in FIG. 1), and by pulling the webbing 14, the take-up shaft 28 is rotated (in the opposite direction to A in FIG. 1). By doing so, it is unwound from the winding shaft 28.

Ratchet wheels 30 and 32 are fixed to both ends of the winding shaft 28, and rotate together with the winding shaft 28. In addition, there are 2
8 to the frame 24, the ratchet wheels 30, 32 are arranged inside the leg plates 26, 26A, and then the winding shaft 28 is inserted from the outside of the leg plate 26 and is pivotally supported. There is. Corresponding to the ratchet wheels 30 and 32, a pendulum 3 is vertically installed.
A main pawl 34 driven by the winding shaft 6 is disposed below the winding shaft 28. The main pawl 34 spans fan-shaped holes 38, 40 formed in the leg plates 26, 26A, and rotates within the fan-shaped holes 38, 40 to engage and separate from the ratchet wheels 30, 32. ing. Therefore, in case of a vehicle emergency, the pendulum 3
6 swings, the main pawl 34 engages with the ratchet wheels 30 and 32, and the take-up rotation of the winding shaft 28 is stopped.

On the other hand, at the tip of the winding shaft 28 on the leg plate 26A side,
An inner end 42A of the mainspring spring 42 having a small biasing force is locked in the locking groove 28A. The outer end 42B of this mainspring spring 42 is locked in a groove 46 formed in the gear 44. The gear 44 is rotatably fitted into the winding shaft 28, and rotates together with the winding shaft 28 via the mainspring spring 42.

In this gear 44, an inner end 48A of a mainspring spring 48 is locked in a groove 47 formed on the side opposite to the mainspring spring 42. This mainspring 48
It has a larger biasing force than the spring spring 42,
Its outer end 48B is locked in a groove 52 formed in the spring cover 50. The spring cover 50 is fixed to the leg plate 26A with screws (not shown), and houses the mainspring springs 42, 48 and the gear 44 inside.

As a result, the winding shaft 28 is connected to the mainspring spring 42,
It is configured to be biased and rotated in the webbing winding direction (direction of arrow A in FIG. 1) by a biasing force of 48.

Further, a ratchet arm 54 is disposed below the winding shaft 28 in correspondence with the gear 44. The ratchet arm 54 is rotatably supported by a pin 56 disposed parallel to the winding shaft 28, and is adapted to engage and separate from the gear 44 when rotated. The pin 56 is attached to the leg plate 26A and this leg plate 26A.
The bearing plate 58 extends through the bearing plate 58 and is fixed thereto. A torsion coil spring 58 is attached to this pin 56 to create a biasing force between the pin 56 and the ratchet arm 54. This biasing force biases the ratchet arm 54 in the direction away from the gear 44, and normally the gear 4
It is arranged at a distance from 4.

A magnet 56 is disposed below the winding shaft 28 in correspondence with the ratchet arm 54.
This magnet 56 is attached to the frame 24 with screws (not shown). This magnet 5
6 is a buckle switch 5 as shown in FIG.
8 and a power supply 61 via an on/off type temperature detector 60 switch connected in series to the buckle switch 58.
The temperature sensor 60 is energized only when the switches of the temperature sensor 60 and the on-off temperature sensor 60 are respectively set to "closed".

When the magnet 56 is excited, the ratchet arm 54 is rotated by the magnetic force of the magnet 56 against the biasing force of the torsion coil spring 58, and the gear 4 is rotated.
4, thereby preventing the gear 44 from rotating. That is, when the buckle switch 58 and the switch of the on/off type temperature sensor 60 are each set to "closed", the ratchet arm 54 is engaged with the gear 44, so that the winding shaft 28 is moved only by the mainspring spring 42. Depending on the force, the webbing winding direction (arrow A in Figure 1)
direction). In this embodiment, the on-off temperature detector 60 is an on-off temperature regulator using a so-called bimetal.

The buckle switch 58 is attached to the buckle device 22, and is opened and closed by engaging and disengaging the tongue plate 18 with the buckle device 22. When the tongue plate 18 is engaged with the buckle device 22, it is “closed”. state.

The on/off type temperature detector 60 is disposed inside the vehicle interior, and is configured to be switched on or off depending on changes in the temperature inside the vehicle interior. In this embodiment, the switch of the on-off type temperature sensor 60 is opened and closed at a temperature of -10
It is designed so that it can be switched at a temperature of -10°C.
It is designed to be in a "closed" state when the temperature is below -10°C, and to be in a "closed" state when the temperature is -10°C or higher.

Therefore, the winding shaft 28 has a temperature of -10
℃, the switch of the on-off type temperature sensor 60 is in the "closed" state, so regardless of whether the tongue plate 18 is disengaged from the buckle device 22 (opening/closing of the buckle switch 58), both mainspring springs 42 , 48 strongly urges and rotates in the webbing winding direction (direction of arrow A in FIG. 1). In addition, if the temperature inside the vehicle is -10℃ or higher,
Even when the switch of the on-off type temperature detector 60 is in the "closed" state, the winding shaft 28 is not connected to the tongue plate 18.
When the buckle device 22 and the buckle device 22 are in the disconnected state (the buckle switch 58 is in the “closed” state), the magnet 56 is not excited, so both mainspring springs 42,
48, the webbing is biased and rotated in the webbing winding direction.
However, when the tongue plate 18 and the buckle device 22 are in the engaged state (the buckle switch 58 is in the "closed" state), the magnet 56 is energized, the ratchet arm 54 engages with the gear 44, and the webbing is pulled out by the biasing force of the mainspring spring 42 alone. 14 is rotated with a weak bias in the winding direction.

Note that the winding force applied to the winding shaft 28 by both mainspring springs 42 and 48 at low temperatures (inside vehicle temperature -10
℃), the webbing 14 is set to a size that will not cause winding defects. Further, the winding force that only the mainspring spring 42 applies to the winding shaft 28 is set to a weak biasing force that does not cause the occupant to feel pressured by the webbing 14 at room temperature (cabin temperature -10° C. or higher). .

Next, the operation of this embodiment will be explained.

FIG. 4 shows a state in which the webbing 14 is worn by the occupant. In this state, the tongue plate 18 is engaged with the buckle device 22, and the webbing 14 is a lap webbing between the tongue plate 18 and the anchor plate 20.
A shoulder webbing is formed between the tongue plate 20 and the slip joint 16.
Further, by engaging the tongue plate 18 with the buckle device 22, the buckle switch 58 is in the "closed" state.

Here, the winding shaft 28 of the webbing winding device 10
When the temperature inside the vehicle becomes less than -10°C, the switch of the on-off type temperature detector 60 becomes "closed", and the ratchet arm 54 shifts to gear 4.
4 and is strongly biased and rotated in the webbing winding direction by the biasing forces of both mainspring springs 42 and 48. When the temperature inside the vehicle reaches -10° C. or higher, the on/off type temperature detector 60 enters the "closed" state, and is weakly biased and rotated in the webbing winding direction by the biasing force of the mainspring spring 42 alone.

That is, when the webbing is attached, the winding force that the winding shaft 28 applies to the webbing 14 depends on the temperature inside the vehicle, and the temperature inside the vehicle is -10°C.
In the above case, the value is smaller than in the case where the temperature is less than -10°C. However, as shown in the prior art, the winding force that contributes to the ability of the webbing 14 to follow the occupant, that is, the tension at the webbing attachment part, decreases at low temperatures compared to at room temperature, so it does not respond to temperature changes in the vehicle interior. This will be made uniform, and the occupant will be prevented from feeling pressured due to temperature changes, and the webbing 14 will be prevented from loosening.

When the occupant wants to release the webbing attachment state, he or she only has to remove the tongue plate 18 from the buckle device 22. When the tongue plate 18 is removed from the buckle device 22, the webbing 14 is wound up by the webbing take-up device 10 and stored along the center pillar 12.

At this time, the winding shaft 28 of the webbing winding device 10
When the tongue plate 18 is removed from the buckle device 22, the buckle switch 58 is closed.
In this state, the webbing is strongly urged to rotate in the webbing winding direction by the urging force of both mainspring springs 42 and 48 regardless of the temperature in the vehicle interior.

That is, in this case, the winding force applied by the winding shaft 28 to the webbing 14 is the winding force of both mainspring springs 42 and 48 without being affected by the temperature inside the vehicle, so that the webbing 14 can be reliably wound. I can do it.

Next, when the occupant wears the webbing 14, he or she only has to pull out the webbing 14 from the webbing take-up device 10 and engage the tongue plate 18 with the buckle device 22, thereby creating the webbing wearing state shown in FIG. becomes.

In this embodiment, since the winding force applied to the winding shaft 28 is changed depending on the temperature conditions, the ability of the webbing 14 to follow the occupant is affected when the webbing is attached. The contributing winding force is equalized to the temperature conditions inside the vehicle,
This prevents the occupant from feeling pressured and from loosening the webbing 14. Thereby, it is possible to obtain an appropriate state of wearing the webbing regardless of temperature changes in the vehicle interior.

In addition, in this embodiment, the mainspring springs 42, 48
The winding force applied to the winding shaft 28 is set to a value that does not cause winding failure of the webbing 14 at low temperatures (vehicle interior temperature less than -10°C).
There is no possibility of winding failure of the webbing 14 in cold regions or the like as in the conventional case.

In this embodiment, the change in the winding force applied to the winding shaft 28 due to temperature conditions is caused by an on/off type temperature detector 60 using bimetal detecting the temperature inside the vehicle and opening/closing the switch. However, the present invention is not limited to this, and other detectors such as a limit switch that uses a shape memory alloy or the like and opens and closes in response to temperature changes may be used. Alternatively, a thermometer may be provided in place of the bimetal, shape memory alloy, or other member, and the detector may be controlled to open or close depending on the temperature indicated by the thermometer.

In addition, a member such as a bimetal or a shape memory alloy is provided so that the ratchet arm 54 can be directly rotated by deforming its shape due to temperature changes in the vehicle interior, so that the ratchet arm 54 is engaged with the gear 44 at room temperature, and the ratchet arm 54 is engaged with the gear 44 at a low temperature. It may also be provided so that it can be separated from the In this case, the buckle switch 58 is omitted. That is, in this case,
The winding shaft 28 is biased and rotated in the webbing winding direction by the biasing force of the mainspring spring 42 only at room temperature.
At low temperatures, the biasing force of the mainspring springs 42 and 48 biases and rotates in the webbing winding direction.

Further, other structures may be used, such as controlling the webbing retracting force in multiple stages or steplessly according to temperature changes in the vehicle interior.

[Effect of the invention] As explained above, the webbing retractor for a seat belt device according to the present invention is a webbing retractor for a seat belt device in which the retracting force is variable according to the conditions. Since the pulling force is changed depending on the temperature condition inside the vehicle, it has an excellent effect of preventing webbing failure due to an increase in frictional force when the temperature drops.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing an embodiment of the webbing retractor for a seat belt device according to the present invention;
The figure is a circuit diagram showing the electric circuit of the magnet shown in Fig. 1, Fig. 3 is a partial sectional view showing the assembled state of Fig. 1, and Fig. 4 is a seat belt device to which the embodiment of the present invention is applied. FIG. 5, which is a front view seen from the front of the vehicle showing a state in which the webbing is worn by an occupant, is a graph showing changes in the winding force that contributes to the followability of the webbing to the occupant with respect to temperature changes. 10... Webbing winding device, 14... Webbing, 60... On/off type temperature detector.

Claims (1)

[Claims for Utility Model Registration] A webbing take-up device for a seat belt device that winds webbing by rotating a take-up shaft by a biasing means, comprising: a first biasing means for rotating the take-up shaft; a second urging means for rotating the take-up shaft; and the first urging means so that the rotational force of the take-up shaft is weaker when the vehicle interior temperature is above a predetermined temperature than when it is below a predetermined temperature. A webbing retractor for a seat belt device, comprising: a control means for preventing the urging force of either one of the second urging means from being applied to the retracting shaft.