GURTAUFROLS

Description

[0001] The present invention relates to a belt retractor having the features of the preamble of claim 1.

[0002] Belt retractors consist of a load-bearing frame and a belt reel mounted rotatably within the frame, onto which a seat belt can be wound. In addition to supporting the belt reel, the frame also serves as a mounting point for attachment to a seat structure or vehicle structure. For this purpose, it is made of a suitably thick sheet steel bent into a U-shaped frame.

[0003] Vehicle seats with safety belt devices are known, for example, from their use as front seats in convertibles, where at least the belt retractors of the safety belt devices are attached to the backrests of the vehicle seats. In this case, due to the lack of a load-bearing B-pillar and for reasons of access to the rear seats or due to the distance from the rear vehicle structure, the belt retractors are preferably integrated into the backrests of the vehicle seats, which must therefore also be designed to absorb the tensile forces acting in the event of a restraint. The belt retractors themselves have all the basic components of a standard belt retractor and are only equipped with various additional modules specifically designed for installation in the backrest, such as a self-aligning inertial sensor or a sensor shutdown device.

[0004] The basic design of a vehicle seat comprises a seat structure consisting of several load-bearing structural components that serve to secure the vehicle seat to the vehicle structure. The seat structure is equipped with springs and padding to improve seating comfort and also serves to attach additional components such as various seat adjustment mechanisms, including the associated electric motors and other components such as heating devices, sensors, displays, headrests, and the like.

[0005] In modern vehicles with autonomous driving systems, there is an increasing demand for greater adjustability of vehicle seats into various orientations and positions. This allows the vehicle occupant to utilize the freedom gained by autonomous driving, for example, for more in-depth communication with other occupants, for extended and more intensive rest periods, or even for work, and to adjust the vehicle seat accordingly. This means that the seat belt device, and in particular the belt retractor, no longer needs to be attached to the vehicle structure as before, but instead to the vehicle seat, as was already the case with the front seats of convertibles, for example.

[0006] One problem, however, is that the belt retractor and its other components require a relatively large amount of space due to their external dimensions, which can make installation in the vehicle seat problematic. This is particularly due to the fact that the seat belt must have a certain minimum thickness to absorb the tensile forces with a given width of, for example, 46 mm and a certain minimum length of, for example, 2500 mm to restrain the occupant. This means that the belt wrap on the belt spool, when the seat belt is fully wound up, has a correspondingly large external diameter due to the volume of the seat belt that needs to be wound up. This large belt wrap is supported by a correspondingly large frame of the belt retractor and by other components such as, for example,a drive device of an irreversible belt tensioner, an electric motor of a reversible belt tensioner, a force limiting device, sensor devices or the like is further enlarged towards the outside, whereby the installation space requirement is increased again.

[0007] From the publication DE 10 2017 109 465 A1, a belt tensioner, referred to therein as a pretensioner, is known which has a belt shaft around which an end section of the seat belt is wound. The pretensioner further comprises a pyrotechnic tensioner drive with a piston guided in a cylinder, which is connected to the belt shaft via a traction wire. The traction wire is wound onto the belt shaft into a coil, inserted laterally into the cylinder, and connected in the cylinder in a tensile-resistant manner to a piston, which in turn delimits a pressure chamber to which a gas generator can supply compressed gas. The gas generator is fixed in one end of the cylinder, which end is curved at an angle of more than 180 degrees relative to a linear section of the cylinder and is arranged between the linear section and the belt shaft.

[0008] Against this background, the object of the invention is to provide a belt retractor with an irreversible belt tensioner, which can also be arranged in a limited installation space of a vehicle seat.

[0009] To achieve this object, a belt retractor having the features of claim 1 is proposed. Further preferred developments of the invention can be found in the subclaims, the figures, and the associated description.

[0010] According to the basic idea of ​​the invention, it is proposed according to claim 1 that the straight linear section extends parallel to the axis of rotation of the belt reel and the longitudinal axis of the assembly, and the tube has a free end which is oriented at an angle of 30 to 90 degrees, preferably perpendicular to the axis of rotation of the belt reel, wherein a gas generator is held in the free end.

[0011] It is further proposed that the belt retractor have at least one web arranged perpendicular to the rotational axis of the belt spool and serving to support the belt retractor and / or to accommodate additional components of the belt retractor. This web allows the belt retractor to be designed with a greater length without compromising the bearing. Furthermore, the web can also serve alternatively or additionally to accommodate or hold additional components.

[0012] It is further proposed that the belt retractor have a frame to which the webs are fixed, and that the tube is fixed between the webs and the frame. The webs, together with the frame, form the fixation of the tube, which is achieved by assembling the belt retractor.

[0013] It is further proposed that the bridge be formed by two or more housing shells. The proposed design of the bridge allows it to be made thicker, with the two housing shells then complementing each other to form the bridge.

[0014] For example, the pyrotechnic belt tensioner can have a drive wheel that can be driven by the drive device to rotate, and the drive wheel can be arranged in a receptacle formed between the two housing shells. The housing shells thus together form the receptacle for the drive wheel, so that the drive wheel and the space provided around it, e.g., for guiding the drive device during the drive movement, are covered to the outside. This can further simplify assembly by first inserting the drive wheel into the receptacle part of one housing shell, and then attaching the other housing shell to complete and secure the drive wheel.

[0015] Furthermore, the two housing shells can each have partial receptacles that complement each other to form a receptacle in which the drive device is guided at least in sections and / or in which the tube is held in sections. Thus, in the assembled position, the housing shells simultaneously form the holder for the tube and / or a guide for the drive device before and during the engagement movement with the drive wheel. If the housing shells together also form the receptacle for the drive wheel, the proposed solution is particularly advantageous, as the drive device is thereby guided in a fixed spatial relationship to the drive wheel.

[0016] It is further proposed that the pipe be curved in a curved section transitioning into the receptacle, and that the receptacle be shaped tangentially to the curvature of the curved section in a transition section. The pipe is held with the curved section in the transition section or is arranged thereon in such a way that the curved section directly adjoins the transition section. The pipe and the receptacle essentially transition from the curved section into the transition section. Since the transition section is shaped tangentially to the curved section, the transition section essentially forms an extension of the curved section of the pipe, without the curvature for guiding the drive device changing abruptly.

[0017] It is further proposed that the drive device be formed by a plurality of loosely adjacent mass bodies, and that a collecting container be provided in which the mass bodies are received after activation of the belt tensioner. The collecting container serves to store the mass bodies after they have passed through the drive wheel and thus prevents a subsequent function of the belt retractor from being disrupted by freely and uncontrollably moving mass bodies.

[0018] The collecting container can preferably be arranged on the web, so that the web is also used to hold the collecting container. The collecting container can also be formed integrally in the form of a hollow space on the web or on one of the housing shells. If the web simultaneously forms the receptacle for the drive wheel and the guide for the drive device, the proposed further development is particularly advantageous because the mass bodies are thereby discharged into the collecting containers in a fixed spatial arrangement after passing through the drive wheel. The housing shells or the web thus form a complete guide path for the mass bodies, starting from the feed from the pipe, via the passage through the drive wheel, to the discharge into the collecting container.

[0019] The proposed solutions allow the gas generator to be aligned and mounted perpendicular to the belt reel's rotation axis. This eliminates sharp edges within or on the seat structure, and the belt pretensioner's positioning allows for sufficient clearance from the vehicle occupant, allowing for sufficiently thick seat padding between the pretensioner and the occupant.

[0020] The invention will be explained below using preferred embodiments with reference to the attached figures. Fig. 1 shows a belt retractor according to the invention in individual parts, in a side view and a sectional view; and Fig. 2 shows the belt retractor from the Figure 1in assembled state in two different oblique views; and Fig. 3 shows a web composed of two housing parts with a receptacle for a drive wheel in different views; and Fig. 4 shows a belt retractor according to the invention according to a further embodiment. Fig. 5 shows a belt retractor according to the invention with a tube according to a further embodiment in the assembled state; and Fig. 6 shows the belt retractor of the Fig. 5 in disassembled state with its individual parts.

[0021] In the Figure 11 shows a belt retractor 1 according to the invention in individual parts and in an assembled state. The belt retractor 1 comprises, as its basic component, a profile rail 7 which is U-shaped in cross-section and has a base surface 10 and two opposing, parallel, wall-shaped legs 8 and 9 which protrude from the base surface 10. The profile rail 7 has an opening 28 in the base surface 10 and in the upper leg 8 in the illustration, through which opening a safety belt 12, which can be seen in the left-hand illustration, is led out to the outside. A cavity 21 is formed between the legs 8, 9 and the base surface 10 of the profile rail 7, in which the components of the belt retractor 1 are arranged and which is closed by an insert part 6.The components of the belt retractor include a belt spool 14, a force limiting device 25, an irreversible belt tensioner 24, several webs 15, 16, 17, 18, 19 and 20 and various additional parts, such as additional sensors, control units and electrical lines, which are not shown for a better illustration of the invention. Furthermore, a reversible belt tensioner or a belt presenter can also be provided. The webs 15, 16, 17, 18, 19 and 20 are supported between the legs 8, 9, the base surface 10 and, when the cavity 21 is closed, on the insert part 6 and form the bearing and holder for the belt retractor 1 or, in particular, for the belt spool 14 and the other rotating parts.

[0022] The external dimensions of the belt reel 14 with the seat belt 12 wound onto it to its maximum tension, as well as the external dimensions of the force limiting device 25 and the pyrotechnic belt tensioner 24, are selected in the cross-sectional area perpendicular to the rotational axis of the belt reel 14 such that they are not larger than the external dimensions of the belt winding on the belt reel 14 with the seat belt 12 wound to its maximum tension. Furthermore, the external dimensions are not larger than the dimensions of the cavity 21 perpendicular to the longitudinal extension of the profile rail 7, so that the belt retractor 1 with the assemblies can be arranged in the cavity 21 of the profile rail 7.

[0023] The webs 15, 16, 17, 18, 19 and 20 are designed in the form of wall sections oriented perpendicular to the longitudinal extent of the profile rail 7, which extend from one of the legs 8 or 9 to the other leg 8 or 9 of the profile rail 7 and are connected to them. Furthermore, the webs 15, 16, 17, 18, 19 and 20 can extend to the base surface 10 of the profile rail 7 and thus fill the entire cross-sectional area of ​​the profile rail 7. The webs 15, 16, 17, 18, 19 and 20 each have one or more openings or projections in which the belt retractor 1 or parts thereof, such as the belt spool 14, are mounted, fastened and / or guided through. Furthermore, for example, one of the webs 15, 16, 17, 18, 19 and 20 can also have a toothing or another type of blocking design in which the belt reel 14 or other parts of the belt retractor can be blocked.In addition, the webs 15, 16, 17, 18, 19, and 20 can also have additional cavities for accommodating other components of the belt retractor, such as pyrotechnic propellants for the pyrotechnic belt tensioner 24, electronic components such as sensors, electronic control units, or memory units. If the webs 15, 16, 17, 18, 19, and 20 extend from one of the legs 8 or 9 to the other leg 8 or 9, the webs 15, 16, 17, 18, 19, and 20 can also be used to stiffen the profile rail 7, which in turn is advantageous for the load bearing and dimensional stability of the profile rail 7 when the occupant is restrained. The components of the belt retractor 1 are deliberately arranged coaxially and one behind the other, so that the assemblies do not increase the external dimensions of the belt retractor radially outwards, and the belt retractor 1 can also be arranged in the narrow, elongated cavity 21 of the profile rail 7.

[0024] In the assembled position, the profile rail 7, together with the insert part 6, forms a frame with an elongated hollow space 21 that is square in cross-section. Since the belt spool 14 with the safety belt 12 wound thereon and the other assemblies are circular in cross-section, an elongated free space with an approximately triangular cross-section is provided in the corners between the belt winding of the belt spool 14, the assemblies and the profile rail 7 and the insert part 6, which free space is used here to arrange a tube 32 of the pyrotechnic irreversible belt tensioner 24. The tube 32 serves to guide a drive device, such as a chain of loosely adjacent mass bodies, or an elastic drive train, which is accelerated when the pyrotechnic belt tensioner 24 is activated and is thereby brought into driving connection with a drive wheel 35.The drive wheel 35 is connected to the belt spool 14 in a rotationally fixed manner via a toothing or a polygonal profile, so that the belt spool 14 is driven by the drive movement via the drive wheel 35 to rotate in the winding direction of the seat belt 12, and the seat belt 12 is tightened. The tube 32 has a linear section 33 and a curved section 34 and is aligned and arranged such that it is arranged with the linear section 33 parallel to the axis of rotation of the belt spool 14 and the longitudinal axis of the force limiting device 25. Furthermore, the linear section 33 is dimensioned so long that, starting from the free end held on the left web 15, it extends laterally of the belt spool 14 and laterally of the force limiting device 25, thereby filling a triangular free space between the belt reel and the lower leg 8 (in the illustration) and the insert part 6.The curved section 34 is shaped such that the drive device is deflected from the linear movement in the linear section 33 in the direction of a circumferential movement in the drive wheel 35.

[0025] In the representations of the Figure 2the belt retractor 1 can be seen without the profile rail 7, only with the insert part 6 and the assemblies. The additional profile rail 7 and the insert part 6 together form a frame for the belt retractor 1, which covers the assemblies of the belt retractor 1 on the outside and forms the holder for the webs 15, 16, 17, 18, 19 and 20. Furthermore, the tube 32 with the linear section 33 is secured against lateral slipping in three recesses 36, 37 and 38 of the webs 18, 17 and 15 and is then covered on the outside by the frame, which is formed by the additional profile rail 7. The tube 32 is thus fixed with the linear section 33 between the webs 18, 17 and 15 and the lower leg 8 of the profile rail 7.

[0026] In the Figure 3The web 19 can be seen in an enlarged view. The web 19 is formed by two housing shells 2 and 3, each with a cover plate 4 and 5, whereby the cover plate 5 is only Figure 1can be seen. The housing shells 2 and 3 each have a circular partial receptacle 27 and 28 with a quarter-circular radius in cross-section, which in the assembled form of the housing shells 2 and 3 complement each other to form a receptacle 26 for the drive wheel 35 with a circumferential guide for the drive device that is semicircular in cross-section. Furthermore, the housing shells 2 and 3 each have a further partial receptacle 22 and 23, which in the assembled form of the housing shells 2 and 3 form a guide channel for the drive device. The partial receptacles 22 and 23 each comprise a curved transition section 31 on the inlet side, which is shaped such that the pipe 32 merges tangentially with its free end therein or is held tangentially therein.The transition sections 31 extend from the planes of the housing shells 2 and 3 toward the pipe 32 and together form a curved inlet channel with a curvature corresponding to the curvature of the adjacent pipe 32. Further, the partial receptacles 22 and 23 are shaped such that, in the assembled form, they form a guide channel directed tangentially toward the outer circumference of the drive wheel 35 and, on the outlet side, form a guide channel leading tangentially away from the drive wheel 35.

[0027] Furthermore, the cover plate 4, which is on the left in the illustration, has a cavity that forms a collecting container 29 for receiving the drive device, e.g., the loose mass body after passing through the drive wheel 35. The web 19 thus forms, through the assembled housing shells 2 and 3 with the cover plate 4, the receptacle 26 for the drive wheel 35 and also completely guides and receives the drive device from the outlet from the tube 32 to its discharge into the collecting container in a fixed spatial relationship to the drive wheel 35.

[0028] The housing shells 2 and 3 are realized as solid block-like walls with a complex shape by the partial receptacles 22, 23, 27 and 28 and can be realized, for example, in the form of a plastic injection-molded part, while the cover plates 4 and 5 are each formed by a metal stamping.

[0029] At the representation of the Figure 1Furthermore, a further holding plate 21 is provided on the right-hand cover plate 5, which is also supported on the profile rail 7 and the cover part 6 and serves, among other things, to hold a vehicle-sensitive sensor.

[0030] The linear section 33 of the tube 32 is dimensioned and arranged to be long enough to extend parallel to the axis of rotation of the belt reel 14 across the entire longitudinal side of the belt reel 14 and parallel to the axis of rotation or longitudinal axis of the force-limiting device 25 across the entire length of the force-limiting device 25. The length is preferably 7 to 15 cm and enables a very high linear acceleration of the drive device in the initial phase of activation of the irreversible belt tensioner 25 before the drive device engages the drive wheel 35.

[0031] In addition to the described advantageous geometry and arrangement of the tube 32, the guidance and reception of the drive device and the drive wheel 35 in the web 19 constitutes an independent invention. In particular, the proposed guidance and reception of the drive device and the drive wheel 35 in the web 19 enables very precise guidance and alignment of the drive device to the drive wheel 35 due to the fixed spatial assignment. Furthermore, the guidance can be implemented particularly cost-effectively in that the web 19 is formed from two housing shells 2 and 3 with the partial receptacles 22, 23, 27 and 28 provided therein, for example as a plastic injection-molded part, which then, when assembled, form the receptacle 26 and the guide for the drive wheel 35 and the drive device.In the assembled position, the housing shells 2 and 3 guide the drive device to the drive wheel 35, both as it passes through the drive wheel 35 and as it is led from the drive wheel 35 into the collecting container 29. The web 19 with the two housing shells 2 and 3 therefore has a thickness that corresponds at least to the width of the drive device. Due to the necessary large width of the web 19, it also provides additional stiffening for the frame formed by the combination of the profile rail 7 and the insert part 6. The web 19 comprises all parts of the guide for the drive device, including the collecting container 29, and can be pre-assembled as an assembly and then inserted into the profile rail 7. The drive wheel 35 then only needs to be inserted into the receptacle 26, either in the position connected to the belt reel 14 or as an individual part.

[0032] The tube 32 has the gas generator 11 held therein at its left free end and is fixed with the free end to the left frontal web 15 of the belt retractor 1 against the direction of pull from the belt retractor 1, so that the tube 32 is supported on the inside of the web 15 when the gas generator 11 is activated, and the reaction forces are transmitted into the frame of the belt retractor 1.

[0033] In the Figure 4a further embodiment of the invention is shown. The belt retractor 1 here additionally has a reversible belt tensioner with an electric motor 36 and a gear 37, which can also be designed to implement further functions such as adjusting the retraction force exerted on the belt spool 14 for comfort purposes or to implement a winding aid for the seat belt into the parking position. The electric motor 36 and the gear 37 are arranged coaxially and in series with the belt spool 14, whereby a very slim and elongated design of the belt retractor 1 can be achieved, e.g. for arranging the belt retractor 1 in very narrow installation spaces in the vehicle structure or a vehicle seat. The tube 32 of the irreversible belt tensioner 25 is aligned here such that the linear section 33 extends parallel to the axis of rotation of the belt spool 14 and away from the belt spool 14.The linear section 33 is dimensioned in such a way that it extends laterally of the gear 37 and the electric motor 37, utilizing the free space available in the corner of the profile rail 7, and is thus as long as possible. This allows the drive mechanism guided in the tube 32 to be accelerated linearly and rectilinearly over the longest possible path before engaging the drive wheel 35 to transmit the drive movement.

[0034] What is common to both described embodiments is that the components of the belt retractor 1, such as the belt spool 14, force limiting device 25 and drive wheel 35, as well as in the second embodiment the gear 37 and the electric motor 36, are arranged coaxially to the axis of rotation of the belt spool 14 and in series with the belt spool 14, so that the belt retractor 1 is as long and narrow as possible. This advantageous elongated basic structure of the belt retractor 1 is now used to provide the tube 32 with the longest possible linear section 33, which is then arranged parallel to the axis of rotation of the belt spool 14 and to the side of the belt spool 14 and another component such as the force limiting device 25 or to the side of the gear 37 and the electric motor 37. In this case, a free installation space in one of the corners of the profile rail 7 is advantageously used to arrange the linear section 33 of the tube 32.

[0035] In the Figure 5 and6 A further embodiment of the invention can be seen. The belt retractor 1 corresponds in its basic structure to that shown in the Figure 4 shown belt retractor 1, so that in this respect the Figure 4 The design of the Figure 5 and 6 differs from the design of the Figure 4in that the free end 13 of the tube 32, in which the gas generator 11 is held, is angled at an angle of approximately 30 to 90 degrees relative to the axis of rotation of the belt spool 14. Furthermore, the belt retractor 1 has two fastening projections 40 and 41 protruding perpendicular to the axis of rotation of the belt spool 14, via which the belt retractor 1 can be fastened to a vehicle seat (not shown). The belt retractor 1 is preferably fastened to the top of the vehicle seat via the fastening projections 40 and 41, so that the seat belt guided out of the belt retractor 1 is fed to the occupant over the shoulder. The free end 13 of the tube 32 is angled such that it extends radially outwards away from the belt retractor 1 between the fastening projections 40 and 41.The advantage of this solution is that any gas flow that may escape upon activation of the gas generator 11 is directed into the vehicle seat and does not exit laterally from the vehicle seat, and the occupants are protected from the gas flow.

Claims

1. Belt retractor (1) comprising - a belt reel (14), - a seat belt (12) that can be wound thereon to form a wound belt, and - a pyrotechnic belt tensioner (24) comprising a drive device which is guided in a tube (32) and can be driven to perform a drive movement, and - at least a first further assembly which is arranged coaxially with the rotational axis of the belt reel (14) and in series with the belt reel (14), and - the tube (32) has a straight linear portion (33) which is arranged on the side of the belt reel (14) and of the further assembly, the linear portion (33) being dimensioned in length such that it extends over the length of the belt reel (14) in the direction of the rotational axis of the belt reel (14) and over the length of the further assembly in the direction of the longitudinal axis, characterized in that - the straight linear portion (33) extends parallel to the rotational axis of the belt reel (14) and the longitudinal axis of the assembly and - the tube (32) has a free end (13) which is oriented at an angle of 30 to 90 degrees, preferably perpendicularly to the rotational axis of the belt reel (14), - a gas generator (11) being held in the free end (13).

2. Belt retractor (1) according to claim 1, characterized in that - the belt retractor (1) comprises at least one support partition (15, 16, 17, 18, 19, 20) which is arranged perpendicularly to the rotational axis of the belt reel (14) and is intended for mounting the belt retractor (1) and / or for receiving further components of the belt retractor (1).

3. Belt retractor according to claim 2, characterized in that - the belt retractor (1) comprises a frame formed by a profile rail (7), on which frame the support partitions (15, 16, 17, 18, 19, 20) are fixed, and - the tube (32) is fixed between the support partitions (15, 16, 17, 18, 19, 20) and the frame.

4. Belt retractor (1) according to either claim 2 or claim 3, characterized in that - at least one support partition (15, 16, 17, 18, 19, 20) is formed by two or more housing shells (2, 3).

5. Belt retractor (1) according to claim 4, characterized in that - the pyrotechnic belt tensioner (24) comprises a drive wheel (35) which can be driven by the drive device to perform a rotational movement, and - the drive wheel (35) is arranged in a receptacle (26) formed between the two housing shells (2, 3).

6. Belt retractor (1) according to either claim 4 or claim 5, characterized in that - the two housing shells (2, 3) each comprise partial receptacles (22, 23, 27, 28) which make up the receptacle (26) in which the drive device is guided at least in portions and / or in which the tube (32) is held in portions.

7. Belt retractor (1) according to claim 6, characterized in that - the tube (32) is curved in a curved portion (34) transitioning into the receptacle (26), and - the receptacle (26) is formed tangentially to the curvature of the curved portion (34) in a transition portion (31).

8. Belt retractor (1) according to any of the preceding claims, characterized in that - the drive device is formed by a plurality of loosely abutting mass bodies, and - a collecting vessel (29) is provided in which the mass bodies are received after activating the irreversible belt tensioner (24).

9. Belt retractor (1) according to claim 8 and according to any of claims 2 to 7, characterized in that - the collecting vessel (29) is arranged on the support partition (15, 16, 17, 18, 19, 20).

10. Belt retractor (1) according to any of claims 1 to 9, characterized in that - the belt retractor (1) comprises two angled fastening lugs (40, 41) which project radially with respect to the rotational axis of the belt reel (14), and - the free end (13) of the tube (32) extends radially outward between the fastening lugs (40, 41).