JPH09109831A - Seat belt retractor - Google Patents

Abstract

(57) An object of the present invention is to easily process an energy absorbing means, to increase a belt feeding amount, and to easily set an absorbable energy to be large. A bobbin 12 is fitted into a rotating shaft 11, and an energy absorbing means 15 is fixed to an outer peripheral surface of the bobbin 12. The energy absorbing means 15 is formed by bending a metal plate material such as aluminum. The energy absorbing means 15 includes a fixing portion 20 for fixing the bobbin 12 and a plurality of winding portions 22 arranged at predetermined intervals for winding the belt 21. And the fixed part 2
It is composed of a connecting portion 23 that connects 0 and the winding portion 22. In this seat belt retractor 1, since the energy absorbing means 15 is formed by bending a metal plate material, the processing is easy, and the height H of the connecting portion 23 is not limited in processing. By increasing the height, the energy that can be absorbed can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat belt retractor used in automobiles and the like, and more specifically,
The present invention relates to a seat belt retractor that locks a bobbin around which a seat belt is wound in an emergency and has a deformable energy absorbing means on the outer peripheral surface of the bobbin.

[0002]

2. Description of the Related Art An automobile is equipped with a seat belt device for protecting an occupant in a collision. In this seat belt device, the withdrawal of the belt is stopped in order to prevent the occupant from jumping forward in the event of a collision, so the kinetic energy of the occupant acts on the belt, and the reaction is exerted on the occupant himself. Therefore, the shock applied to the occupant can be reduced by efficiently absorbing this kinetic energy. Conventional seat belt devices that absorb kinetic energy of occupants include, for example, (1) Japanese Patent Application Laid-Open No. 55-38189 and (2) Japanese Utility Model Laid-Open No. 64-144.
Japanese Patent Laid-Open No. 54-54, (3) Japanese Patent Laid-Open No. 7-101310, and the like have been proposed.

The above-mentioned "safety belt fixing device" (1)
As shown in FIG. 8, the end portion of the safety belt 110 (renumbered) is fixed to the spindle 111 by the fixing loop 112. The spindle 111 is covered with a sleeve 114 of expandable plastic material. The safety belt 110 is wound around the sleeve 114. When the vehicle collides, the withdrawal of the safety belt 110 is stopped by the locking of the spindle 111. Then, a large tension is applied to the safety belt 110 whose pulling is stopped by the kinetic energy toward the front of the occupant, the sleeve 114 is compressed by this tension and is plastically deformed to the small diameter side, and the safety belt 110 is slightly pulled out. As a result, a part of the kinetic energy of the occupant is absorbed. The material and shape of the sleeve 114 can be changed as appropriate.

Further, in the "webbing retractor" of the above (2), a rib 121 which is plastically or elastically deformable is provided around the bobbin 120 as shown in FIG.
A webbing (belt) 122 is wound on the outer side of 1. The rotation of the bobbin 120 is locked when the automobile collides, and the rib 121 is deformed to the smaller diameter side to absorb the kinetic energy of the occupant. Rib 121
The shape of can be changed appropriately.

Further, in the above-mentioned "seat belt retractor" (3), as shown in FIG. 10, a take-up wheel 131 is fitted on the outer peripheral position of the webbing take-up shaft 130. As shown in the perspective view of FIG. 11, the take-up wheel 131 is formed of a plate material into a substantially cylindrical shape, and a flange 132 having a substantially cylindrical shape is formed by burring at appropriate intervals.
Are provided toward the inside of the winding wheel. The webbing W is wound around the outer peripheral surface of the winding wheel 131. When the vehicle collides, the webbing take-up shaft 130 is locked to stop the feeding of the webbing W,
Further, the flange 132 extending in the radial direction of the bobbin is crushed toward the small diameter side by the tension applied to the webbing W and is plastically deformed to absorb a part of the kinetic energy of the occupant. The shape of the flange 132 shown here can be changed, and the flange 132 can be formed by drawing instead of burring.

[0006]

However, the above-mentioned (1)
In (2) and (2), since the shapes of the sleeve 114 and the rib 121 are complicated and formed of resin, there is a problem that the processing is difficult and the energy that can be absorbed at the time of deformation becomes small.

In the above (3), the energy that can be absorbed is determined by the height of the flange 132, but since the flange 132 is formed by burring or drawing, the height of the flange 132 can be made so large. Therefore, there is a problem that the energy that can be absorbed cannot be increased. In addition, it is difficult to improve the processing accuracy with this type of processing method, and it is difficult to stabilize the energy absorption rate. Then, this invention solves the said subject and an object of this invention is to provide the seatbelt winding device which can be processed easily and can increase the energy which can be absorbed.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to lock a bobbin around which a seat belt is wound in an emergency, and to keep the winding diameter surface of the belt on the smaller diameter side with a belt tension of a predetermined value or more. In a seat belt retractor in which energy absorbing means for absorbing energy applied by plastic deformation is provided on the outer peripheral surface of the bobbin, the energy absorbing means is provided on the outer peripheral surface of the bobbin by bending a metal plate material. A fixing part for fixing, a winding part for winding the seat belt, and a connecting part that connects the fixing part and the winding part and is buckled and deformed by the belt tension of the predetermined value or more. This can be solved by a seat belt retractor characterized by being provided.

According to this structure, the connecting portion which is buckled and deformed by the belt tension of the energy absorbing means which is equal to or more than the predetermined value is accurately and stably formed by bending the metal plate material. Therefore, it becomes extremely easy to increase the height of the connecting portion and increase the absorbed energy.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a seat belt retractor according to the present invention will be described below with reference to the drawings. FIG. 1 shows a first seat belt retractor according to the present invention.
FIG. 2 is a cross-sectional view of a main part of the embodiment, FIG. 2 is a cross-sectional view of the main part for explaining the operation at the time of collision of the first embodiment, FIG. 3 is a cross-sectional view of the main part of the second embodiment, and FIG. 5 is a sectional view of the main part of FIG.
Is a cross-sectional view of the essential parts of the fourth embodiment, FIG. 6 is a cross-sectional view of the essential parts of the fifth embodiment, and FIG. 7 is a cross-sectional view of the essential parts of the sixth embodiment.

Although the seat belt retractor 1 of the present invention is not shown in its entirety, as is well known, it is provided with a frame fixed to a vehicle body of an automobile or the like, and a winding mechanism attached to this frame. A rotary shaft 11 and a bobbin 12, which will be described later, are provided as part of the mechanism. Then, as shown in FIG. 1 which is a cross section of the main part of the belt winding portion of the seat belt retractor 1, a cylindrical bobbin 12 is fitted on a rectangular rotary shaft 11, for example. The rotating shaft 11 is
Normally, it can rotate, but in the event of a vehicle collision, the rotation is stopped by emergency locking means (not shown). A plurality of protrusions 13 are provided on the outer peripheral surface of the bobbin 12.

Further, on the outer peripheral surface of the bobbin 12, there is fitted an energy absorbing means 15 which is plastically deformed toward the small diameter side by the belt tension when the automobile collides. In the first embodiment, the energy absorbing means 15 is divided into two (each divided into right and left) by 180 degrees. The energy absorbing means 15 is formed by bending a metal plate material having a predetermined strength such as aluminum. The bending cross-sectional shape has a wavy basic shape, and the bending width is a structure extending over the entire width of the metal plate material. And this energy absorbing means 1
5 is a fixing portion 20 fixed to the bobbin 12, and a belt 21.
A plurality of winding parts 22 arranged at predetermined intervals for winding
And the connecting portion 23 that extends in the bobbin radial direction at a predetermined height H (bobbin radial direction height) that connects the fixed portion 20 and the winding portion 22 and buckles and deforms with a belt tension of a predetermined value or more. It is configured.

A plurality of holes 30 are provided in the fixing portion 20, and the protrusions 13 of the bobbin 12 are inserted into the holes 30 and fixed. The method of fixing the protrusion 13 can be arbitrarily selected such as welding, caulking, and screwing. The rotary shaft 11 and the bobbin 12 are provided with slits 25 and 26, and the ends of the belt 21 are inserted therein. A wide portion 27 is provided at the end of the slit 26 of the bobbin 12, and a pin 28 is provided at the center thereof. And
The end of the belt 21 is wrapped around the pin 28 and folded back, and the folded back portion is fixed to the body of the belt 21 to prevent it from coming off.

In this seat belt retractor 1,
Normally, the belt 21 can be pulled out, but in the event of a vehicle collision, the emergency lock means is activated to stop the rotation of the rotary shaft 11. Then, the unwinding of the belt 21 wound around the bobbin 12 attached to the rotating shaft 11 is stopped, the kinetic energy toward the front of the occupant is applied to the belt 21, and the tension of the belt 21 becomes a predetermined value or more.

When the tension of the belt 21 exceeds a predetermined value,
As shown in FIG. 2, the winding portion 22 of the energy absorbing means 15
Due to the pressing force F acting on the central direction,
Buckles and deforms. In this case, since the pressing force F acts in the central direction, the pressing force F is received by the winding portion 22, and the connecting portion 2
3 is buckled and deformed without simply falling, the winding portion 22 moves to the center side over the entire circumference, and the diameter of the winding portion 22 decreases. As a result, the belt 21 is pulled out by a predetermined length. That is, in this case, the kinetic energy toward the front of the occupant is converted into the tension of the belt 21, and the connecting portion 23 of the energy absorbing means 15 is buckled and deformed by this tension, so that a part of the kinetic energy of the occupant is absorbed. To be done. Therefore, the reaction applied from the belt 21 to the occupant is reduced, and the shock due to the collision can be reduced. The energy that can be absorbed during the buckling deformation of the connecting portion 23 changes depending on the height H of the connecting portion 23. That is, the connecting portion 23
The higher the height H, the larger the energy that can be absorbed.

Since the seat belt retractor 1 is formed by bending the metal plate material as described above, the processing is facilitated. Further, since the height H of the connecting portion 23 is not limited by the processing like the conventional burring processing, the connecting portion 2
The height H of 3 can be increased, and the seat belt withdrawal amount can be set as large as possible, so that the energy that can be absorbed can be increased.

Although the energy absorbing means 15 is divided into two in the above-described first embodiment, the energy absorbing means 35 may be integrated as in the second embodiment shown in FIG. This can reduce the number of parts to be mounted.

Further, as in the third embodiment shown in FIG.
It is also possible to provide a plurality of protrusions 37 on the outer peripheral surface of the bobbin 36 and dispose the protrusions 37 between the adjacent connecting portions 23 of the energy absorbing means 35. As a result, the fixing of the energy absorbing means 35 can be strengthened, and the connecting portion 23 can be prevented from falling down, so that higher energy absorption can be achieved.

As in the fourth embodiment shown in FIG. 5, the engaging groove 41 is provided on the outer peripheral surface of the bobbin 40, and a part of the energy absorbing means 42 on the inner peripheral side is raised to the inner side to engage the engaging piece 43. It is also possible to insert the locking piece 43 into the locking groove 41 for locking. This can prevent the energy absorbing means 42 from being displaced.

Further, as in the fifth embodiment shown in FIG.
A plurality of recessed grooves 46 are provided on the outer peripheral surface of the bobbin 45, and the fixing portions 48 at both ends of a large number (six) of substantially U-shaped energy absorbing means 47 are inserted into the recessed grooves 46 by press fitting or insert molding. The energy absorbing means 47 can be fixed. In this case, since the energy absorbing means 47 has a simple shape, the processing becomes easier.

Further, as in the sixth embodiment shown in FIG.
A plurality of substantially U-shaped through holes 51 and locking holes 52 are provided on the outer peripheral portion of the bobbin 50, and a first fixing portion 54 on the inner peripheral side of the corrugated energy absorbing means 53 and second fixing portions 55 on both ends are formed. It is also possible to fix the energy absorbing means 53 by press-fitting (press-fitting from one side surface of the bobbin) or insert molding into the through hole 51 and the locking hole 52, respectively. In the above embodiment, the rotating shaft 11 and the bobbin 1
Although the case where the components 2, 36, 40, 45 and 50 are provided separately has been described, it goes without saying that a configuration in which they are integrated may be employed.

[0022]

As described above, in the seat belt retractor of the present invention, the energy absorbing means includes the fixing portion for fixing to the outer peripheral surface of the bobbin by bending the metal plate, and the seat belt. Since a winding portion for winding and a connecting portion that connects the fixing portion and the winding portion and is buckled and deformed by a belt tension of a predetermined value or more are provided, the seat belt It is possible to easily process the connecting part that absorbs the energy related to the seat belt, and there is no restriction on the height of this connecting part to increase the degree of freedom in setting the seat belt. The energy that can be absorbed can be increased by increasing the height of the connecting portion.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part of a first embodiment of a seat belt retractor according to the present invention.

FIG. 2 is a cross-sectional view of essential parts showing the operation of the first embodiment of the seat belt retractor according to the present invention.

FIG. 3 is a cross-sectional view of essential parts of a second embodiment of a seat belt retractor according to the present invention.

FIG. 4 is a sectional view of an essential part of a third embodiment of the seat belt retractor according to the present invention.

FIG. 5 is a sectional view of an essential part of a seat belt retractor according to a fourth embodiment of the present invention.

FIG. 6 is a cross-sectional view of essential parts of a seat belt retractor according to a fifth embodiment of the present invention.

FIG. 7 is a cross-sectional view of essential parts of a sixth embodiment of a seat belt retractor according to the present invention.

FIG. 8 is a sectional view showing a first example of a seat belt retractor according to a conventional example.

FIG. 9 is a sectional view showing a second example of a seat belt retractor according to a conventional example.

FIG. 10 is a third example of a seat belt retractor according to a conventional example.
It is sectional drawing which shows an example.

11 is a perspective view showing a wheel of the seat belt retractor shown in FIG.

[Explanation of symbols]

 1 Seatbelt retractor 11 Rotating shaft 12, 36, 40, 45, 50 Bobbin 15, 35, 42, 47, 53 Energy absorbing means 20, 48 Fixing part 22 Winding part 53 First fixing part 55 Second fixing part

Claims (1)

[Claims] 1. A bobbin around which a seat belt is wound is locked in an emergency and absorbs energy applied by plastically deforming the winding diameter surface of the belt to a small diameter side with a belt tension of a predetermined value or more. In the seat belt retractor in which the energy absorbing means is provided on the outer peripheral surface of the bobbin, the energy absorbing means includes a fixing portion for fixing the outer peripheral surface of the bobbin by bending a metal plate, and a seat belt. A seat belt winding, comprising: a winding portion for winding, and a connecting portion that connects the fixing portion and the winding portion and is buckled and deformed by a belt tension of the predetermined value or more. Taker.