CN215322445U

CN215322445U - Safety belt retractor

Info

Publication number: CN215322445U
Application number: CN202121188472.6U
Authority: CN
Inventors: 赵伟; 林智涵; 黄永亮
Original assignee: Yanfeng Automotive Safety Systems Co Ltd
Current assignee: Yanfeng Automotive Safety Systems Co Ltd
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2021-12-28
Anticipated expiration: 2031-05-31

Abstract

The present invention relates to a seatbelt retractor, including: a U-shaped frame (1), a winding drum (3) rotatably supported in the frame for winding the woven belt (2); a force limiting member (4) which fails when a predetermined load threshold is exceeded; and a pretensioning device (10) having a drive wheel (6) which is coupled to the belt drum via a force-limiting member and which can be driven such that the belt drum rotates in a webbing retraction direction in order to pretension the webbing. The drive wheel is connected on a first side facing the winding reel in a rotationally fixed manner directly to the force-limiting member, and in addition to this rotationally fixed connection, the drive wheel is rotatably supported relative to the winding reel. Optionally, the belt retractor further comprises a lockable catch wheel (9) which is connected to the catch wheel in a rotationally fixed manner directly on a second side facing away from the belt drum. The safety belt retractor is compact in structure and has a stable force limiting function.

Description

Safety belt retractor

Technical Field

The utility model relates to the technical field of safety, in particular to a safety belt retractor. The belt retractor can be used in a vehicle, in particular in a motor vehicle, for example a passenger vehicle.

Background

In motor vehicles, safety belt devices are an important component of occupant restraint systems, and in particular in the event of a traffic accident, they can provide protection for the occupants from injury or minimize injury. With the development and progress of automotive technology, the requirements for the performance of the seatbelt device are continuously increasing.

The seat belt device may have a seat belt retractor which may be equipped with a vehicle-sensing device and a locking mechanism, which are known in the art in various forms. The vehicle-sensing device can sense safety-relevant states of the motor vehicle, such as vehicle acceleration and/or vehicle inclination, and activate the locking mechanism under predetermined conditions, so that the spool is locked in the webbing-pull-out direction. The seatbelt device may have a webbing sensing device, wherein an excessively fast withdrawal of webbing from the seatbelt retractor may result in the spool being locked in the webbing withdrawal direction. For related prior art, for example, see patent documents CN109177915A and CN 109159755A.

Furthermore, seat belt arrangements with a pretensioning function are known, which comprise a pretensioning device. The pretensioning device can pretension the safety belt in an emergency situation of the vehicle in order to better restrain the vehicle occupant. Pretensioning devices are likewise known in the prior art in various forms. For example, the pyrotechnic pretensioning device can comprise a ball gear and a gas generator, wherein, when the gas generator is ignited, a plurality of steel balls are ejected one after the other, engaging with the ball gear, so that the ball gear drives the tape drum to rotate in the tape retracting direction. Pretensioning devices are also known which have a serpentine-shaped flexible strip which can be pushed out and which engages with a toothed wheel and thereby drives the spool in rotation in the webbing take-up direction. Generally, the pretensioner is disposed on one side of a frame of the seatbelt retractor, and the vehicle-sensing device and the locking mechanism are disposed on the other side of the frame.

In some cases, the pretensioning device may provide excessive pretensioning force when activated. After activation of the pretensioning device, it is possible for the vehicle occupant to be over-restrained, wherein an excessive shoulder belt force spike of the webbing could cause injury to the vehicle occupant. For this purpose, a force limiter can be provided in the belt device, which can limit the load-bearing capacity of the belt retractor.

The inventor of the present invention has found in his research that, in the prior art known from practice, it may be necessary to first overcome the pretensioning force exerted by the pretensioning device on the spool before the force-limiting device is activated. In an emergency situation of the vehicle, the shoulder belt force has an uncertainty during the force limitation process immediately after the pretensioning process. The safety belt retractor according to the prior art is complex in structure, large in number of parts and high in size requirement on parts in the assembly aspect.

SUMMERY OF THE UTILITY MODEL

The object of the utility model is to provide a belt retractor with a force-limiting function and a pretensioning function, which can be of compact construction, the pretensioning function at least substantially not affecting the force-limiting function.

The object is achieved by a seatbelt retractor, comprising:

a U-shaped frame;

a winding drum rotatably supported in the frame for winding a webbing;

a force limiting member configured to fail when a predetermined load threshold is exceeded; and

a pretensioning device having a drive wheel coupled to the belt drum via a force-limiting member, the drive wheel being drivable such that the belt drum coupled to the drive wheel is rotated in a webbing take-up direction in order to pretension the webbing;

wherein the drive wheel is connected in a rotationally fixed manner directly to the force-limiting member on a first side facing the tape reel, the drive wheel being rotatably supported relative to the tape reel in addition to a rotationally fixed coupling between the drive wheel and the tape reel via the force-limiting member.

In some embodiments, the belt retractor can further comprise a lockable stop member, in particular a stop wheel, which is directly connected in a rotationally fixed manner to the stop member on a second side facing away from the belt drum.

In this context, the expression "rotationally fixed" may mean that the two parts being connected cannot, or substantially cannot, rotate relative to each other. The two parts being connected may be slightly rotatable relative to each other or may be rotatable relative to each other with a predetermined backlash, either due to unintentional play (e.g. due to manufacturing tolerances), or due to intentional play (e.g. due to intentionally designed backlash), or due to the elasticity of the various components of the overall connection system. For example, when two components are welded or glued together, or interference fit or integrally formed, they can rotate together so that they can be considered to be non-rotatably connected.

In some embodiments, the seatbelt retractor may include a frame in which the spool is rotatably supported.

The belt retractor can be used in general for vehicles, for example for aircraft, ships, amusement rides or land vehicles, in particular for motor vehicles such as cars.

In some embodiments, the force limiting member may be a force limiting rod.

In some embodiments, the force-limiting lever can be connected with one end thereof in a rotationally fixed manner directly to the winding reel and with the other end thereof in a rotationally fixed manner directly to the drive wheel.

In some embodiments, the force limit lever may plastically deform when a predetermined torsional load threshold is exceeded.

In some embodiments, the force limit lever may shear when a predetermined torsional load threshold is exceeded. For example, the force limiting lever may have a weak portion.

In some embodiments, the torque-proof connection of the force-limiting lever to the belt reel and/or the drive wheel can be broken when a predetermined torsional load threshold is exceeded.

In some embodiments, the drive wheel may be a gear or a friction wheel.

In some embodiments, the drive wheel may have a central aperture that may receive a force limiting member and a stop member.

In some embodiments, the central bore may be configured as a stepped bore, and the central bore may have a first bore section with a larger diameter and a second bore section with a smaller diameter and a step between the first bore section and the second bore section.

In some embodiments, the stop member may have a first shaft section with a larger diameter and a second shaft section with a smaller diameter, and a first collar shoulder on an end of the first shaft section facing away from the second shaft section and a second collar shoulder between the first shaft section and the second shaft section.

In some embodiments, the first shaft section of the stop member may be received in a first bore section, the second shaft section of the stop member may be received in a second bore section, the first shoulder may abut the drive wheel, the second shoulder may abut a step of the central bore, and the second bore section may also receive a force limiting member.

In some embodiments, the stop member can be connected with the drive wheel in a form-fitting manner.

In some embodiments, the stop member can be connected in the first and second shaft portion by means of a segmented spline in a rotationally fixed manner directly to the drive wheel in the first and second bore portion of the central bore, and/or the force limiting member can be connected by means of a spline in a rotationally fixed manner directly to the drive wheel in the second bore portion of the central bore.

Alternatively or in addition to the form-locking connection, the stop member can be connected to the drive wheel in a force-locking and/or material-locking manner, and/or the force-limiting member can be connected to the drive wheel in a force-locking and/or material-locking manner.

In some embodiments, the stop member and force limiting member may abut or abut each other in the second bore section of the central bore.

In some embodiments, the drive wheel may have a hub on a first side facing the tape drum, and the tape drum may have a stepped bore, the hub being rotatably supported in a bore section of the stepped bore of the tape drum having a larger diameter.

In some embodiments, the seatbelt retractor may have a vehicle sensing device and/or a webbing sensing device that co-acts with the stop member.

In some embodiments, the drive wheel may be configured as a ball gear having teeth and ball sockets between the teeth, the pretensioning device comprising a gas generator and a set of drive steel balls which can be fired by gas generated by the gas generator when the gas generator is triggered and can thus come into engagement with the ball gear and drive the ball gear. The term "drive steel ball" is to be understood here in general as a rolling element having an inertial mass, for example a sphere, ellipsoid or roller made of stainless steel, aluminum or other metallic material or made of a composite material.

In some embodiments, a structural unit comprising a tape reel, a force limiting member, a drive wheel and a stop member is rotatably supported in the frame.

In some embodiments, the seatbelt retractor can comprise a locking plate with a toothed ring which interacts with a stop member in which a spring-pretensioned locking pawl, guided movably, can engage with the toothed ring against the spring force of a pretensioning spring, the locking plate being fixedly mountable to the frame.

In some embodiments, the belt retractor can comprise a vehicle-sensing device which interacts with the stop member on the side of the locking plate facing away from the belt drum in the axial direction.

In some embodiments, the seat belt retractor may include a support plate on an opposite side of the spool from the locking plate in the axial direction, the support plate may be fixedly mounted to the frame, the support plate may be for supporting a coil spring that pretensions the spool in a webbing-take-up direction such that the webbing is received on the spool without being worn by the occupant.

The above-mentioned features, the features to be mentioned below and the features shown in the drawings individually can be combined with one another as desired, provided that the combined features are not mutually inconsistent. All technically feasible combinations of features are the technical content contained in this document.

Drawings

An exemplary embodiment of a seatbelt retractor according to the present invention will be described below with reference to the accompanying drawings. Wherein:

fig. 1 is a longitudinal sectional view of a seatbelt retractor according to an embodiment of the present invention.

Fig. 2 is a partially enlarged longitudinal sectional view of a plurality of components of the seatbelt retractor of fig. 1 in an assembled state.

Detailed Description

Fig. 1 is a longitudinal sectional view of a seatbelt retractor according to an embodiment of the present invention, and fig. 2 is a partially enlarged longitudinal sectional view of parts of the seatbelt retractor of fig. 1 in an assembled state.

The seatbelt retractor may comprise a frame 1 configured for mounting in a vehicle. The belt retractor can be fastened to a vehicle body or a seat back, for example, by means of a frame 1. Typically, the frame 1 can be designed as a U-shaped frame comprising two legs, each of which can have an opening, and a floor plate connecting the two legs, in which legs the belt drum 3 of the belt retractor can be directly or indirectly rotatably supported.

The take-up spool 3 is used to wind the flexible webbing 2 of the seatbelt device. On one axial end side of the winding reel 3 (the right end side in fig. 1) a support plate 5 may be provided, which may be fixedly mounted to the frame 1. The support plate 5 may be used to support a coil spring that pretensions the spool 3 in the webbing take-up direction so that the webbing 2 is stored on the spool 3 without being worn by the occupant. The coil spring may be provided with an end cap 23 which may be fixed to the support plate 5 so as to cover the coil spring. The support plate 5 has an opening 12 so that the winding reel 3 can pass through the support plate 5.

The seatbelt retractor may include a force limiting device, which may mainly include the force limiting member 4. The force-limiting member 4 can be a force-limiting rod, which can be connected with its one end 4b in a rotationally fixed, in particular directly rotationally fixed manner, to the winding reel 3 and with its other end 4a in a rotationally fixed manner to a drive wheel 6, which is described in more detail below. For example, the force limiting member 4 may be a torsion bar having splines at both ends thereof. The force limiting member 4 may be configured to fail when a predetermined load threshold is exceeded. For example, the force-limiting member 4 can be plastically deformed or alternatively sheared off when a predetermined torsional load threshold is exceeded, or alternatively the torque-proof connection of the force-limiting member 4 to the winding reel 3 can be broken when a predetermined torsional load threshold is exceeded.

The belt retractor can comprise a pretensioning device 10 having the drive wheel 6 already mentioned above, which is coupled to the belt drum 3 via the force-limiting member 4. In the embodiment shown, the drive wheel 6 is designed as a ball gear with teeth and ball sockets between the teeth. The pretensioning device 10 can comprise a gas generator 16 and a set of drive balls which can be fired by the gas generated by the gas generator 16 when the gas generator 16 is activated and can thus be brought into engagement with the drive wheel 6 and drive the drive wheel 6 under the guidance of the serpentine 17, so that the belt drum 3 coupled to the drive wheel 6 via the force limiting member 4 is rotated in the web retracting direction in order to pretension the webbing 2. The pretensioning device 10 can also have a ball reservoir 15, by means of which the balls and the flames and debris generated by the gas generator 16 can be prevented from escaping into the interior of the vehicle after activation of the pretensioning device 10.

The seatbelt retractor may include a detent wheel 9 that can be locked. The drive wheel 6 can be connected to the retaining wheel 9 in a rotationally fixed manner, in particular directly.

The drive wheel 6 may have a hub 6c on a first side facing the tape drum 3, the tape drum 3 may have a stepped bore 20, and the hub 6c may be rotatably supported in a bore section 20a of the stepped bore 20 of the tape drum 3 having a larger diameter. The drive wheel 6 thus partially overlaps the tape reel 3, viewed in the axial direction. In addition to the rotationally fixed coupling via the force limiter 4 between the drive wheel 6 and the winding reel 3, the drive wheel 6 is rotatably supported relative to the winding reel 3 by means of a hub 6c in a bore section 20a of the stepped bore 20 of the winding reel 3.

The drive wheel 6 may have a central hole 18 which may receive the force limiting member 4 and the detent wheel 9. The drive wheel 6 can have a first half 6a and a second half 6b in the axial direction, wherein the central bore 18 has a larger diameter in the first half 6a, i.e. the first bore section 18a, and a smaller diameter in the second half 6b, i.e. the second bore section 18 b. In the central hole 18, a step, for example, an annular step surface, is formed between the first half 6a and the second half 6 b.

The detent wheel 9 can have a first shaft section 19a with a larger diameter and a second shaft section 19b with a smaller diameter, as well as a first collar shoulder 21 on the end of the first shaft section 19a facing away from the second shaft section 19b and a second collar shoulder 22 between the first shaft section 19a and the second shaft section 19 b. The first shaft section 19a of the detent wheel 9 can be received in the first bore section 18 a. The second shaft section 19b of the detent wheel 9 can be received in the second bore section 18 b. The first annular shoulder 21 can abut against the drive wheel 6. The second shoulder 22 may abut a step of the central bore 18. The locking wheel 9 can be connected in a rotationally fixed manner in the first shaft section 19a and the second shaft section 19b by means of a segmented spline to the drive wheel 6 directly in the first bore section 18a and the second bore section 18b of the central bore 18. The force-limiting component 4 projects with its end 4a into the second bore section 18 b. In a second bore section 18b of the central bore 18 of the drive wheel 6, the detent wheel 9 and the force limiting member 4 can abut against one another with their end faces or can lie next to one another.

The seatbelt retractor may include a lock plate 7. The latch plate 7 may be fixedly mounted to the frame 1. The locking plate 7 has an opening 11 so that the detent wheel 9 can pass through the locking plate 7. The locking plate 7 can fix the detent wheel 9 axially and can interact with the detent wheel 9. For example, the detent wheel 9 can have a slide in which a spring-biased detent pawl 8 is guided in a movable manner, and the detent plate 7 can have a ring gear 13. The locking pawl 8 is held out of engagement with the toothed ring 13 of the locking plate 7 by the spring force of the pretensioning spring and, against the spring force of the pretensioning spring, engages with the toothed ring 13 and thus locks the locking wheel 9. The structural unit comprising the spool 3, the force limiting member 4, the drive wheel 6 and the detent wheel 9 can be supported rotatably relative to the frame 1 directly or indirectly via the opening of the frame 1 and/or the opening 12 of the support plate 5 and/or the opening 11 of the blocking plate 7. For example, the winding reel 3 may be indirectly supported rotatably with respect to the frame 1 through the openings 11, 12.

On the side of the locking plate 7 facing away from the belt drum 3 in the axial direction, the belt retractor can comprise a vehicle-sensing device 14 which interacts with the detent wheel 9. The vehicle-sensing device 14 can sense safety-relevant states of the motor vehicle, such as vehicle acceleration and vehicle inclination, and can cause the locking of the detent wheel 9 if the vehicle acceleration or vehicle inclination exceeds a respective threshold value, and thus the spool 3 is locked in the webbing-pull-out direction, so that the webbing 2 cannot be further unwound or pulled out of the spool 3. The catch wheel 9 can also interact with a webbing sensor device, wherein an excessively rapid withdrawal of the webbing 2 from the belt retractor can lead to the catch wheel 9 being locked. The vehicle sensor device 14 can be provided with an end cap 24, which can be connected to the locking plate 7 in order to cover the vehicle sensor device 14.

In contrast to the seat belt retractors known from the prior art, in the embodiment of the seat belt retractor according to the utility model shown in the figures, the pretensioning device 10 does not act directly on the belt drum 3, wherein the ball gear is connected to the belt drum 3 only via the force-limiting lever. In an emergency situation of the vehicle, the pretensioning device has substantially no influence on the force limiting function during the force limiting process immediately after the pretensioning process. A substantially constant shoulder belt force can be generated on the webbing 2 when the force limiting means is active. In addition, the seat belt retractor is compact in structure, small in number of parts, and easy to manufacture and assemble.

It is noted that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be understood that the terms "comprises" and "comprising," and other similar terms, when used in this specification, specify the presence of stated operations, elements, and/or components, but do not preclude the presence or addition of one or more other operations, elements, components, and/or groups thereof. The term "and/or" as used herein includes all arbitrary combinations of one or more of the associated listed items. In the description of the drawings, like reference numerals refer to like elements throughout.

The thickness of elements in the figures may be exaggerated for clarity. It will be further understood that if an element is referred to as being "on," "coupled to" or "connected to" another element, it can be directly on, coupled or connected to the other element or intervening elements may be present. Conversely, if the expressions "directly on … …", "directly coupled with … …", and "directly connected with … …" are used herein, then there are no intervening elements present. Other words used to describe the relationship between elements, such as "between … …" and "directly between … …", "attached" and "directly attached", "adjacent" and "directly adjacent", etc., should be similarly interpreted.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element could be termed a second element without departing from the teachings of the present inventive concept.

Finally, it is pointed out that the above-described embodiments are only intended to be understood as an example of the utility model and do not limit the scope of protection of the utility model. It will be apparent to those skilled in the art that modifications may be made in the foregoing embodiments without departing from the scope of the utility model.

Claims

1. A seatbelt retractor, comprising:

a U-shaped frame (1);

a spool (3) rotatably supported in the frame for winding a webbing;

a force limiting member (4) configured to fail when a predetermined load threshold is exceeded; and

a pretensioning device (10) having a drive wheel (6) which is coupled to the belt drum via a force-limiting member and which can be driven such that the belt drum coupled to the drive wheel is rotated in a webbing take-up direction in order to pretension the webbing;

characterized in that the drive wheel (6) is connected in a rotationally fixed manner directly to the force-limiting member (4) on a first side facing the winding reel, said drive wheel being rotatably supported relative to the winding reel, with the exception of a rotationally fixed coupling between the drive wheel and the winding reel via the force-limiting member.

2. The seatbelt retractor according to claim 1, further comprising a lockable stop member, the drive wheel (6) being directly torque-proof connected with the stop member on a second side facing away from the belt drum.

3. The seatbelt retractor according to claim 2, wherein the stop member is a stop wheel (9).

4. The seatbelt retractor according to one of claims 1 to 3, characterized in that the force limiting member (4) is a force limiting rod which is connected with its one end (4b) directly to the belt drum (3) in a rotationally fixed manner and with its other end (4a) directly to the drive wheel (6) in a rotationally fixed manner.

5. The seatbelt retractor according to claim 2 or 3, wherein the drive wheel (6) has a central hole (18) which receives a force limiting member and a stop member.

6. The seatbelt retractor according to claim 5, wherein the central bore (18) is configured as a stepped bore having a first bore section (18a) with a larger diameter and a second bore section (18b) with a smaller diameter and a step between the first and second bore sections;

the stop member has a first shaft section (19a) with a larger diameter and a second shaft section (19b) with a smaller diameter, and a first collar shoulder (21) on the end of the first shaft section facing away from the second shaft section and a second collar shoulder (22) between the first shaft section and the second shaft section;

wherein the first shaft section of the stop member is received in a first bore section, the second shaft section of the stop member is received in a second bore section, the first shoulder abuts the drive wheel, the second shoulder abuts the step of the central bore, and the second bore section also receives a force limiting member.

7. The seatbelt retractor according to claim 6, wherein the stop member is connected in the first and second shaft section by means of a segmented spline in a rotationally fixed manner directly to the drive wheel (6) in the first and second bore section of the central bore, and the force limiting member (4) is connected in a rotationally fixed manner by means of a spline directly to the drive wheel in the second bore section of the central bore.

8. The seatbelt retractor according to claim 6, wherein the stop member and the force limiting member (4) abut against each other or are in close proximity to each other in the second bore section of the central bore.

9. The seatbelt retractor according to any one of claims 1 to 3, wherein the drive wheel (6) has a hub portion (6c) on a first side facing the belt drum, the belt drum (3) having a stepped bore (20), the hub portion being rotatably supported in a bore section (20a) of the stepped bore of the belt drum having a larger diameter.

10. The belt retractor according to one of claims 1 to 3, characterised in that the drive wheel (6) is designed as a ball gear with teeth and ball sockets between the teeth, the pretensioning device (10) comprising a gas generator (16) and a set of drive steel balls which can be fired by the gas generated by the gas generator when the gas generator is triggered and can thus come into engagement with the ball gear and drive the ball gear.

11. The seatbelt retractor according to claim 2 or 3, wherein a structural unit including a spool, a force limiting member, a driving wheel and a stopper member is rotatably supported in the frame.

12. The seatbelt retractor according to claim 2 or 3, characterized in that the seatbelt retractor comprises a locking plate (7) with a toothed ring (13) which interacts with a stop member in which a spring-pretensioned locking pawl (8) guided movably can engage with the toothed ring against the spring force of a pretensioning spring, which locking plate is fixedly mounted to the frame.

13. The seatbelt retractor according to claim 2 or 3, characterized in that the seatbelt retractor has a vehicle sensing device (14) and/or a webbing sensing device which co-acts with a stop member.