SAFETY BELT RETRACTOR AND SAFETY BELT DEVICE

Abstract

A safety belt retractor, comprising a frame (8) and a belt retracting cylinder (1), the retracting cylinder (1) being rotatably supported in the frame (8) and being composed to be used for winding a woven belt (2). The frame (8) comprises: a back plate (8h), which has a first side and a second side which are opposite to each other, and a first opening (20); a plurality of first supporting legs (8a,8b), extending from the first side of the back plate (8h); a first support plate (11), which is provided with a second opening (21) and is connected to free end regions of the first supporting legs (8a, 8b); a plurality of second supporting legs (8c, 8d, 8e, 8f), extending from the second side of the back plate (8h); and a second supporting plate (9), connected to the free end regions of the second supporting legs (8c, 8d, 8e, 8f). The first opening (20) and the second opening (21) receive the belt retracting cylinder (1). The safety belt retractor is simple in structure and easy to assembly. Also provided is a safety belt device comprising the safety belt retractor.

Claims

1.-9. (canceled)

10. A safety belt retractor comprising a frame and a belt reel, wherein the belt reel is rotatably supported in the frame and is configured for winding a webbing, wherein the frame comprises: a back plate having a first side and a second side opposite to each other and having a first opening; first support legs extending from the first side of the back plate; a first support plate having a second opening and connected to free end regions of the first support legs; second support legs extending from the second side of the back plate; and a second support plate connected to free end regions of the second support legs; wherein the first opening and the second opening are configured to receive the belt reel.

11. The safety belt retractor as recited in claim 10, wherein the safety belt retractor comprises a locking mechanism having a movable locking claw and a locking plate, wherein the locking plate is formed by the second support plate, wherein the second support plate has a third opening with an internal tooth system, wherein the locking claw, when engaged with the internal tooth system, causes that the belt reel is locked in a webbing pull-out direction.

12. The safety belt retractor as recited in claim 11, wherein the safety belt retractor comprises a sensing unit configured to cooperate with the locking mechanism, wherein the sensing unit is arranged at a side of the second support plate facing away from the back plate.

13. The safety belt retractor as recited in claim 11, wherein the safety belt retractor comprises a stop wheel, which is rotation-fixedly connected with the belt reel at an axial end of the belt reel facing the back plate and carries the movable locking claw of the locking mechanism, wherein the locking claw, when engaged with the internal tooth system, causes that stop wheel is locked in the webbing pull-out direction.

14. The safety belt retractor as recited in claim 10, wherein the safety belt retractor comprises a pretension device having a driving element and a driven element, wherein the driven element is configured to be directly or indirectly rotation-fixed with respect to the belt reel, wherein the pretension device, when activated, can directly or indirectly drive the belt reel in the webbing winding direction.

15. The safety belt retractor as recited in claim 13, wherein the safety belt retractor comprises a pretension device having a driving element and a driven element, wherein the driven element is rotation-fixedly arranged on the stop wheel between the back plate and the second support plate, wherein the pretension device, when activated, can drive the stop wheel in the webbing winding direction.

16. The safety belt retractor as recited in claim 13, wherein the safety belt retractor comprises a load limiting device, which rotation-fixedly connects the belt reel with the stop wheel, wherein the load limiting device can transmit a torque no more than a predetermined threshold value between the belt reel and the stop wheel.

17. The safety belt retractor as recited in claim 16, wherein the load limiting device is configured as a torsion bar, which is received in a chamber of the belt reel, and is plastically deformable when a predetermined torsion load is exceeded, in order to limit the torque transmittable between the belt reel and the stop wheel through the torsion bar; wherein the torsion bar has a first end adjacent to the first opening and a second end adjacent to the second opening, and is rotation-fixedly connected to the stop wheel at its first end, and is rotation-fixedly connected to the belt reel at its second end.

18. The safety belt retractor as recited in claim 10, wherein at least one of the first support legs and the second support legs are integrally formed with the back plate.

19. The safety belt retractor as recited in claim 10, wherein the first support legs each have a bent end region, wherein the bent end regions of the first support legs have at least three fixing portions for fixing the first support plate in total.

20. The safety belt retractor as recited in claim 19, wherein the end regions of the first support legs are bent inward.

21. The safety belt retractor as recited in claim 10, wherein the frame has two first support legs opposite to each other; wherein the two first support legs are symmetrical with each other about a longitudinal axis of the safety belt retractor, wherein the first support legs each have two fixing portions for fixing the first support plate.

22. The safety belt retractor as recited in claim 10, wherein the second support legs each have a bent end region, wherein the bent end regions of the second support legs have at least three fixing portions for fixing the second support plate in total.

23. The safety belt retractor as recited in claim 22, wherein the end regions of the second support legs are each bent inward.

24. The safety belt retractor as recited in claim 10, wherein the frame has four distributed second support legs, each of which has one fixing portion for fixing the second support plate; wherein the four second support legs are spaced apart from each other at a uniform angular interval with respect to a longitudinal axis of the safety belt retractor.

25. The safety belt retractor as recited in claim 10, wherein the first opening and the second opening are configured as rotation bearings for the belt reel.

26. The safety belt retractor as recited in claim 10, wherein the second opening is configured as an axial stop for the belt reel.

27. The safety belt retractor as recited in claim 22, wherein the second support plate is configured as an axial stop for the stop wheel.

28. A safety belt device having a webbing, wherein the safety belt device further comprises the safety belt retractor as recited in claim 10, wherein the webbing is wound on the belt reel of the safety belt retractor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Now, the invention will be described in more detail with reference to the attached drawings. The schematic drawings are briefly described as below:

[0051] FIG. 1 is a longitudinal sectional view of a safety belt retractor according to an embodiment of the invention; and

[0052] FIG. 2 is an exploded view of a portion of the safety belt retractor of FIG. 1.

EMBODIMENTS

[0053] Now, an embodiment of a safety belt retractor according to the invention is described with reference to FIGS. 1 and 2. It can be understood, the invention is not limited to the specific embodiment shown in the drawings. The safety belt retractor together with a webbing 2 schematically shown in FIG. 1, as an overall system, may be referred to as a safety belt device.

[0054] The shown safety belt retractor comprises a belt reel 1 and a frame 8, in which the belt reel 1 is rotatably supported and is configured for winding the webbing 2. The safety belt retractor further comprises a sensing unit 10, a locking mechanism 4 and a pretension device 7, which are known in the prior art, as mentioned above. Here, the sensing unit 10, the locking mechanism 4, the pretension device 7 and a load limiting device 3 are all optional, and any one or more of these structural units may be spared according to the actual requirements. The sensing unit 10 may be a sensing unit for sensing an acceleration and/or a tilt angle of a vehicle and/or a pull-out acceleration of the webbing. The sensing unit 10 may also comprise a plurality of sub-units capable of sensing at least one of the just-mentioned parameters respectively. When the sensing unit 10 senses the emergency of the vehicle, for example, the vehicle is about to collide, the locking mechanism 4 may be activated by the sensing unit 10.

[0055] It is common in the prior art that the sensing unit and the locking mechanism are arranged at a side of the frame, while the pretension device is arranged at the other side of the frame. On the contrary, in this embodiment of the present invention, the sensing unit 10, the locking mechanism 4 and the pretension device 7 are all arranged at the same side of the frame 8. More specifically, the sensing unit 10 is arranged at the side of a second support plate 9 facing away from a back plate 8h, and at least a driven element such as a ball gear 6 of the pretension device 7 is arranged between the back plate 8h and the second support plate 9 which will be explained later.

[0056] As shown in FIG. 2, the frame 8 comprises: the back plate 8h having a first side and a second side opposite to each other and having a first opening 20; two first support legs 8a, 8b extending from the first side of the back plate and opposite to each other; a first support plate 11 having a second opening 21 and connected to free end regions of the first support legs; four second support legs 8c, 8d, 8e, 8f extending from the second side of the back plate; and the second support plate 9 connected to free end regions of the second support legs. The first opening 20 and the second opening 21 receive the belt reel 1. The first support legs 8a, 8b may be integrally formed with the back plate 8h. The second support legs 8c, 8d, 8e, 8f may also be integrally formed with the back plate 8h.

[0057] In FIG. 2, the two first support legs 8a, 8b are symmetrical with each other about a longitudinal axis of the safety belt retractor, and each have an end region bent inward, wherein the bent end region of each first support leg has two fixing portions for fixing the first support plate 11. The first support plate 11 may be connected to the first support legs, for example, by bolts.

[0058] As can be seen from FIG. 2, the frame 8 has four distributed second support legs 8c, 8d, 8e, 8f, each of which has an end region bent inward and has one fixing portion for fixing the second support plate 9 in the bent end region. The four second support legs 8c, 8d, 8e, 8f may be spaced apart from each other at a uniform angular interval with respect to the longitudinal axis of the safety belt retractor. The second support plate 9 may be connected to the free bent end regions of the second support legs 8c, 8d, 8e, 8f, for example, by bolts.

[0059] Here, the optional locking mechanism 4 is advantageously integrated in the safety belt retractor. The locking mechanism 4 may comprise a locking plate and a movable locking claw (not shown), wherein the locking plate is formed by the second support plate 9. For this purpose, the second support plate 9 may have a third opening 19, which may have an internal tooth system. The locking claw, when engaged with the internal tooth system, causes that the safety belt retractor is locked in the webbing pull-out direction.

[0060] The safety belt retractor may comprise a stop wheel 5, which is rotation-fixedly connected to the belt reel 1 at an axial end of the belt reel 1 facing the back plate 8h. The locking claw (not shown) of the locking mechanism 4 may be received in the stop wheel 5, more specifically, may be received in a recess (not shown) of the stop wheel 5.

[0061] The pretension device 7 may comprise a ball gear 6 rotation-fixedly fitted on the stop wheel 5, and a steel ball shooting device. The steel ball shooting device, when activated, may shoot a plurality of steel balls to drive the ball gear 6 in the webbing winding direction, wherein the ball gear can drive the stop wheel 5 and in turn drive the belt reel 1 to rotate in the webbing winding direction. As a result, a pretension function of the safety belt retractor can be realized on requirements.

[0062] In the sense of the invention, it is not inevitably necessary that the entire pretension device 7 is completely positioned in a space between the back plate 8h and the second support plate 9. It can be understood that at least a portion of the entire pretension device 7 is positioned in the space between the back plate 8h and the second support plate 9. In particular, the driven element such as the ball gear 6 of the pretension device 7, which is rotation-fixedly connected with the stop wheel 5, may be completely positioned in the space between the back plate 8h and the second support plate 9. In particular, the driving element of the pretension device 7, such as a snakelike element of the steel ball shooting device, may be only partially positioned in the space between the back plate and the second support plate, or even may be positioned completely outside this space.

[0063] It's particularly advantageous, the optional load limiting device 3 is integrated in the safety belt retractor. The load limiting device 3 rotation-fixedly connects the belt reel 1 with the stop wheel 5, and can transmit a torque no more than a predetermined threshold value between the belt reel 1 and the stop wheel 5. As shown in FIG. 1, the load limiting device 3 may be configured as a torsion bar, which is received in a chamber of the belt reel 1, and which is plastically deformable when a predetermined torsion load is exceeded, in order to limit the torque transmittable between the belt reel 1 and the stop wheel 5 through the torsion bar. The torsion bar has a first end 3b adjacent to the first opening 20 and a second end 3a adjacent to the second opening 21, and is rotation-fixedly connected to the stop wheel 5 at its first end 3b and is rotation-fixedly connected to the belt reel 1 at its second end 3a.

[0064] If the optional load limiting device 3 as shown in FIG. 1 is spared, the belt reel 1 and the stop wheel 5, as two separate components, may also be replaced with one integral belt reel, wherein a portion of the integral belt reel may have the function of the stop wheel 5.

[0065] It is also possible that the pretension device 7 and the sensing unit 10 as shown in FIG. 1 exchange their positions. If the optional pretension device 7 shown in FIG. 1 is spared, the optional sensing unit 10 may also be arranged between the back plate 8h and the second support plate 9.

[0066] The safety belt retractor as shown in FIGS. 1 and 2 may operate as below:

[0067] When an emergency occurs to a vehicle equipped with the safety belt retractor as described above, for example, in case of an imminent collision or rollover of the vehicle, the sensing unit 10 may sense the emergency of the vehicle, and cause the locking claw of the locking mechanism 4 to move away from its rest position until the locking claw engages with the internal tooth system of the second support plate 9. The engagement of the locking claw with the internal tooth system causes that the stop wheel 5 is stopped in the webbing pull-out direction, and thus the belt reel 1 is locked in the webbing pull-out direction. In this way, the belt reel 1 and the stop wheel 5 can only rotate in the webbing winding direction, and can't rotate in the webbing pull-out direction.

[0068] In addition, the pretension device 7 is activated, for example, a gas generator of a pyrotechnic pretension device is ignited, wherein the generated gas shoots the plurality of steel balls contained in a snakelike tube. The steel balls successively drive the ball gear 6 in the webbing winding direction, and thus the ball gear 6 drives the stop wheel 5 and in turn drives the belt reel 1 to rotate in the webbing winding direction. The steel ball shooting device may comprise a winding snakelike tube, which is provided with a gas generator at its one end and accommodates the plurality of steel balls, and which aims at the ball gear 6 at its other end. The steel balls shot out of the snakelike tube may impact the teeth of the ball gear and mesh into ball sockets between the teeth of the ball gear. In FIG. 1, only a circular cross section of the snakelike tube is schematically shown.

[0069] If the torque to be transmitted between the stop wheel 5 and the belt reel 1 through the load limiting device 3 that is configured as a torsion bar exceeds a predetermined threshold value, the torsion bar can be plastically deformed, thereby limiting the maximal load of the safety belt retractor and thus limiting the peak value of the shoulder webbing force of the webbing 2, and hence preventing the vehicle occupant from being injured due to the excessive peak value of the shoulder webbing force.

[0070] It's particularly advantageous, the first opening 20 and the second opening 21 may be configured as rotation bearings for the belt reel 1. It's also advantageous, the second opening 21 may be configured as an axial stop for the belt reel 1. Moreover, it's advantageous, the locking plate 9 may be configured as an axial stop for the stop wheel 5. It's appropriate, the two axial ends of the safety belt retractor may be additionally provided with a respective end cover for covering some components of the safety belt retractor.

[0071] Finally, it should be pointed out, the above-mentioned specific embodiments are only for understanding the invention, and don't limit the protection scope of the invention. For those skilled in the art, modifications can be made on the basis of the specific embodiments, and such amendments don't depart from the protection scope of the invention.