SEAT BELT REEL WITH TENSIONER DRIVE

Abstract

Tightener drive (30) with - a gas generator (31), - a drive wheel (34), - a feed pipe (32) connecting the gas generator (31) and the drive wheel (34) and having an outlet opening (A32) facing the drive wheel (34), and - at least one thrust element (33) which is located wholly or at least partially in the feed tube (32) before the gas generator (31) is triggered and is pushed through the outlet opening (A32) towards the drive wheel (34) after the gas generator (31) is ignited, wherein - a stop element (35) is arranged in the feed tube (32) between the thrust body (33) and the gas generator (31), - a stop device (37) is present which allows the thrust body (33) to pass, but stops the stop element (35), - the stop device (37) is located outside the feed tube (32) - viewed in the direction of movement (B) of the thrust body (33) - behind the outlet opening (A32) of the feed tube (32) and - the distance between the outlet opening (A32) of the feed pipe (32) and the stop device (37) is dimensioned such that a section of the stop element (35) and / or - if present - a sealing element (36) arranged between the gas generator (31) and the stop element (35) and driving the stop element (35) remains inside the feed pipe (32) when the stop element (35) collides with the stop device (37) and is stopped by it, characterized in that the stop device (37) has at least two sections, namely - a deflection section (371) that forms a ramp towards the drive wheel (34) and deflects the direction of movement (B) of the thrust body (33) or at least the direction of movement (B) of a section of the thrust body (33) when passing the stop device (37) towards the drive wheel (34), and - a barrier section (372) which is arranged at an angle to the deflection section (371) and forms a buffer for the stop element (35).

Description

[0001] The invention relates to tensioner drives and to belt retractors equipped with tensioner drives.

[0002] Among other things, the invention relates to a tensioner drive which comprises at least: a gas generator, a drive wheel, a feed pipe which connects the gas generator and the drive wheel and has an outlet opening facing the drive wheel, and at least one thrust body which is located entirely or at least partially in the feed pipe before the gas generator is triggered and is pushed through the outlet opening in the direction of the drive wheel after the gas generator is ignited.

[0003] A tensioner drive is known, for example, from German patent DE 10 2014 224 490 B3. In the previously known tensioner drive, a deformable thrust rod is located in a multiply bent feed tube before the gas generator is triggered. After the gas generator is ignited, it is pushed out of the feed tube toward the drive wheel. As it passes through the feed tube, the thrust rod is bent plastically and / or elastically several times.

[0004] Another tensioner drive is described in the international patent application WO 2018 / 170 050 A1.

[0005] A tensioner drive with the features according to the preamble of patent claim 1 is known from the German laid-open specification DE 10 2010 034 622 A1.

[0006] The invention is based on the object of proposing a construction for a tensioner drive of the type described which is particularly easy to manufacture mechanically and which prevents the escape of hot drive gas from the gas generator at the end of the tensioning process.

[0007] This object is achieved according to the invention by a tensioner drive having the features according to claim 1. Advantageous embodiments of the tensioner drive according to the invention are specified in subclaims.

[0008] A key advantage of the tensioner drive according to the invention is that, at the end of the tensioning process, the hot gas from the gas generator is reliably held inside the supply pipe, thus preventing gas leakage. This is achieved by the stop device, which is itself located outside the supply pipe—as seen in the direction of movement of the thrust body—and thus behind the outlet opening of the supply pipe, and stops the stop element behind the outlet opening. The outlet opening is to be understood as the point on the supply pipe at which the supply pipe loses its gas-tightness and the gas from the gas generator would leave the supply pipe if the supply pipe did not remain closed with the assistance of the stop element.

[0009] A further significant advantage of the tensioner drive according to the invention is that the arrangement of the stop device outside the gas-carrying supply pipe enables particularly simple assembly of the parts; because the sealing effect of the supply pipe is not achieved by technical measures inside the supply pipe, but by measures outside the supply pipe.

[0010] The stop device is preferably arranged between the outlet opening of the feed pipe and the drive wheel and stops the stop element before it reaches the drive wheel.

[0011] With a view to simple assembly, it is considered advantageous if the stop device is simply placed as a separate part on a wall section which - seen in the direction of movement of the thrust body and stop element - is located behind the outlet opening of the feed pipe and is thus easily accessible.

[0012] The wall section preferably adjoins the supply pipe in one piece. The wall section on which the stop device is mounted is preferably channel-shaped, or at least partially channel-shaped, to facilitate easy installation of the stop device.

[0013] In an embodiment variant considered advantageous, it is provided that the stop element is not sealing with respect to the feed pipe itself and a sealing element is arranged in the feed pipe between the gas generator and the stop element and the distance between the outlet opening of the feed pipe and the stop device is smaller than the sum of the length - seen in the direction of movement - of the stop element, the length of the sealing element and - if present - the length of any intermediate elements located between the sealing element and the stop element.

[0014] If no intermediate elements are present, the distance between the outlet opening of the feed pipe and the stop device is preferably smaller than the sum of the length - seen in the direction of movement - of the stop element and the length of the sealing element in front of it.

[0015] In another embodiment variant considered advantageous, it is provided that the stop element is sealing with respect to the feed pipe itself and the distance between the outlet opening of the feed pipe and the stop device is smaller than the length - seen in the direction of movement - of the sealing stop element.

[0016] The angle of the barrier section is preferably in a range between 80° and 100° relative to the direction of movement of the stop element upon impact with the barrier section; in other words, the barrier section extends perpendicularly or at least approximately perpendicularly to the direction of movement.

[0017] The angle between the barrier section and the deflection section is preferably an acute angle, which is particularly preferably between 60° and 80°.

[0018] It is particularly advantageous if the barrier section—as seen in a plan view perpendicular to the direction of movement—forms an undercut, which creates a protruding abutting edge. Upon impact with the stop element, the abutting edge preferably results in a positive, interlocking connection between the stop element and the stop device.

[0019] The ramp preferably comprises a flat ramp surface which has an angle of inclination - relative to the direction of movement immediately before reaching the stop device - between 30° and 60°.

[0020] With a view to optimal steering of the thrust body into the drive wheel, it is considered advantageous if the ramp has a ramp surface curved towards the drive wheel.

[0021] The stop element preferably has a protruding nose portion and a radially outer and rearwardly offset ring portion.

[0022] When the stop element hits the stop device, the nose section preferably first hits the deflection section and is guided by it in the direction of the drive wheel, whereby the stop element is specifically aligned, before the ring section then hits the barrier section and is stopped by it.

[0023] With regard to the deflection of the nose section and the alignment of the stop element, it is considered advantageous if the protruding nose section is conical.

[0024] The ring section is preferably deformable and is at least slightly deformed by the barrier section when it hits it, preferably forming a positive connection that hooks the stop element and the stop device.

[0025] The thrust body is preferably a strand-shaped element which is plastically and / or elastically bent by the stop device after passing the outlet opening of the feed pipe.

[0026] With a view to a defined control of the thrust body after the ignition of the gas generator, it is considered advantageous if the thrust body already rests with a front section on the deflection section before the ignition of the gas generator.

[0027] The stop element may comprise two or more sections, each section having different material properties.

[0028] The invention also relates to a belt retractor equipped with a belt reel for winding and unwinding a safety belt and with a tensioner drive as described above. Regarding the advantages of the belt retractor and advantageous embodiments of the belt retractor according to the invention, reference is made to the above statements concerning the tensioner drive, which apply accordingly to the belt retractor.

[0029] The invention is explained in more detail below using exemplary embodiments; by way of example, Fig. 1 in a three-dimensional exploded view, components of an embodiment of a belt retractor according to the invention, which is equipped with an embodiment of a tensioner drive according to the invention, Fig. 2-5 a stop element, a sealing element and a stop device of the tensioner drive according to Fig. 1 in more detail.

[0030] For the sake of clarity, the same reference symbols are always used in the figures for identical or comparable components.

[0031] The Fig. 1 shows a three-dimensional exploded view of an embodiment of a belt retractor 10, which includes, among other things, a belt reel 20 and a tensioner drive 30.

[0032] The tensioner drive 30 can be seen in the Fig. 1 includes, among other things, a gas generator 31, a feed pipe 32, a strand-shaped thrust body in the form of a thrust body rod 33 made of a deformable material and a drive wheel 34.

[0033] Between the gas generator 31 and the thrust rod 33, a stop element 35 and a sealing element 36 are located in the feed tube 32. The stop element 35 cooperates with a stop device 37 which, viewed in the direction of movement B of the thrust rod 33, is arranged behind the outlet opening A32 of the feed tube 32 and allows the thrust rod 33 to pass, but stops the stop element 35.

[0034] The stop device 37 rests on a wall section 38, which, viewed in the direction of movement B of the thrust rod 33, is located behind the outlet opening A32 of the supply pipe and is integrally connected to the supply pipe, forming a pipe-supporting wall arrangement. The outlet opening A32 is to be understood as the point on the supply pipe 32 at which the supply pipe loses its gas-tightness and the gas from the gas generator 31 would leave the supply pipe 32 if the supply pipe were not closed by the sealing element 36 or the stop element 35.

[0035] The distance between the outlet opening A32 of the feed tube 32 and the stop device 37 located on the wall section 38 is dimensioned such that a section of the stop element 35 and the sealing element 36 arranged between the gas generator 31 and the stop element 35 and driving the stop element 35 remain within the feed tube 32 when the stop element 35 strikes the stop device 37 and is stopped by it.

[0036] The drive wheel 34 can be directly connected to the belt reel 20 or alternatively can be coupled to the belt reel via a coupling 40.

[0037] If, in the event of an accident or a dangerous situation, the tensioner drive 30 is triggered and the gas generator 31 is ignited, the gas of the gas generator 31 will press the sealing element 36 and the stop element 35 located behind it as well as the thrust rod 33 in the direction of the drive wheel 34, so that the drive wheel 34 is set in a rotational movement and drives the belt reel 20 in such a way that it has a Fig. 1 winds up the safety belt (not shown for reasons of clarity).

[0038] In order to be able to push the thrust rod 33 through the feed pipe 32 provided with bends 32a and 32b with the lowest possible driving force or driving energy, the thrust rod 33 is preferably made of a material that is particularly well deformed elastically and / or plastically, for example plastic. Fig. 1, the reference numeral 33a denotes the front end face of the thrust rod, which strikes the drive wheel 34 after the ignition of the gas generator 31.

[0039] In the final phase of the tensioning operation, as already mentioned, the gas from the gas generator 31 is to be held inside the feed pipe 32; this is achieved by the interaction of the stop element 35 and the stop device 37, which retain the sealing element 36 in the feed pipe 32 at the end of the tensioning process. In connection with the Fig. 2 to 5, preferred embodiments for the stop element 35 and the stop device 37 are explained in more detail below.

[0040] The Fig. 2 shows the sealing element 36, the stop element 35 and the thrust rod 33 immediately before the end of the tightening process.

[0041] The stop device 37, which rests on the wall section 38 behind the outlet opening A32 of the feed pipe 32, has a deflection section 371, which deflects the direction of movement B (see Fig. 3 and Fig. 4) the thrust rod 33 is deflected toward the drive wheel 34 upon passing the stop device 37. For this purpose, the deflection section 371 is designed as a ramp, which, viewed in the direction of movement B, comprises a front flat ramp surface 371a and a curved ramp surface 371b located behind it.

[0042] The stop device 37 further comprises a barrier section 372 which is arranged at an angle to the deflection section 371 and forms a buffer stop for the stop element 35.

[0043] In other words, the deflection section 371 of the stop device 37 is designed and dimensioned with a view to deflecting the thrust rod 33, whereas the barrier section 372 has no deflection function but merely serves to stop the stop element 35. Therefore, the barrier section 372 has no or no significant influence on the movement of the thrust rod 33.

[0044] In order to support the described deflection effect of the deflection section 371 and the buffer stop effect of the barrier section 372, the wall section 38 is preferably bent in the area between the outlet opening A32 of the feed pipe 32 and the stop device 37.

[0045] The Fig. 3 shows the Fig. 2 again in a different view. It can be seen that the barrier section 372 forms a stop surface P, which, in a plan view along the viewing direction B', which is perpendicular to the direction of movement B of the stop element 35 before impact with the barrier section 372, forms a type of undercut, thereby achieving a particularly reliable stopping effect and making it impossible for the stop element 35 to pass through the barrier section 372.

[0046] The Fig. 4 shows in another representation the design of barrier section 372 and deflection section 371 in the stop device 37 according to the Fig. 1 to 3. It can be seen that the angle α between the flat ramp surface 371a of the deflection section 371 and the direction of movement B before reaching the stop device lies in a range between preferably 30 and 60 degrees, whereas the angle β between the stop surface P of the barrier section 372 and the direction of movement B is preferably above 90 degrees. An angle above 90° leads to the mentioned undercut and forms a protruding abutting edge K, which is pressed into the stop element 35 upon impact and leads to a positive connection or, as it were, a locking of the stop element 35 with the barrier section 372.

[0047] The described selection of angles α and β results in the angle y between the barrier section 372 and the deflection section 371 being an acute angle. To form the abutting edge K, this angle is preferably between 60° and 80°.

[0048] The Fig. 5 shows the Fig. 2 to 4 after completion of the tightening process. It can be seen that the stop element 35 has impacted the barrier section 372 and has thus been abruptly stopped. By stopping the stop element 35, the sealing element 36 is held inside the supply tube 32, i.e., in front of the outlet opening A32, thus preventing the gas from the gas generator 31 from escaping; because the supply tube 32 remains sealed by the sealing element 36.

[0049] The Fig. 3 and Fig. 5 further show a preferred embodiment of the stop element 35. The stop element 35 preferably has a protruding nose portion 351 and a radially outer ring portion 352 offset to the rear.

[0050] When the stop element 35 strikes the stop device 37, the nose section 351 initially strikes the deflection section 371 or the ramp formed by it, so that the stop element 35 is deflected toward the drive wheel 34. This deflection optimizes the positioning of the radially outer ring section 352 relative to the stop surface P and the abutment edge K of the barrier section 372, thus reliably ensuring the stopping of the stop element 35.

[0051] With regard to the aforementioned deflection effect of the nose portion 351, it is considered advantageous if it is conical. The pitch angle of the conical nose portion 371 is preferably adapted to the angle of the flat ramp surface 371a of the deflection portion 371, namely such that the conical nose portion 351 rests flatly on the deflection portion 371 at the time the ring portion 352 strikes the barrier portion 372.

[0052] In the embodiment according to the Fig. 1 to 5, a sealing element 36 and a stop element 35 are provided. Alternatively, it is possible to dispense with the sealing element 36 if the stop element 35 itself is sealing and remains within the feed pipe 32 with a sealing section when the front section of the stop element 35 abuts the stop device 37 or its barrier section 372.

[0053] Although the invention has been illustrated and described in detail by means of preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention. List of reference symbols 10 belt retractors 20 belt reels 30 tensioner drive 31 Gas generator 32 feed pipe 32a Curvature 32b Curvature 33 Shear bar 33a frontal surface 34 Drive wheel 35 Stop element 36 Sealing element 37 Stop device 38 wall section 40 Clutch 351 Nose section 352 ring section 371 deflection section 371a flat ramp surface 371b curved ramp surface 372 barrier section A32 Exit opening B Direction of movement B' Viewing direction K butt edge P stop surface R bending radius α angle β angle γ angle

Claims

[1] Tensioner drive (30) with - a gas generator (31), - a drive wheel (34), - a supply pipe (32) connecting the gas generator (31) and the drive wheel (34) and having an outlet opening (A32) facing the drive wheel (34), and - at least one thrust body (33) which is located entirely or at least partially in the feed pipe (32) before the gas generator (31) is triggered and is pushed through the outlet opening (A32) in the direction of the drive wheel (34) after the gas generator (31) is ignited, wherein - a stop element (35) is arranged in the feed pipe (32) between the thrust body (33) and the gas generator (31), - a stop device (37) is provided which allows the thrust body (33) to pass but stops the stop element (35), - the stop device (37) is arranged outside the feed pipe (32) - seen in the direction of movement (B) of the thrust body (33) - behind the outlet opening (A32) of the feed pipe (32) and - the distance between the outlet opening (A32) of the supply tube (32) and the stop device (37) is dimensioned such that a section of the stop element (35) and / or - if present - a sealing element (36) arranged between the gas generator (31) and the stop element (35) and driving the stop element (35) remains within the supply tube (32) when the stop element (35) strikes the stop device (37) and is stopped by it, characterized by that the stop device (37) has at least two sections, namely - a deflection section (371) which forms a ramp in the direction of the drive wheel (34) and deflects the direction of movement (B) of the pushing body (33) or at least the direction of movement (B) of a section of the pushing body (33) when passing the stop device (37) in the direction of the drive wheel (34), and - a barrier section (372) which is arranged at an angle to the deflection section (371) and forms a buffer stop for the stop element (35). [2] Tensioner drive (30) according to claim 1, characterized by , that - a wall section (38), which is preferably at least partially groove-shaped, adjoins the feed pipe (32) in one piece and which - viewed in the direction of movement (B) of the thrust body (33) - is arranged behind the outlet opening (A32) of the feed pipe (32) and - the stop device (37) is arranged on the wall section (38) and in the direction of movement (B) in front of the drive wheel (34) and the stop element (35) stops before reaching the drive wheel (34). [3] Tensioner drive (30) according to one of the preceding claims, characterized by , that - the angle of the barrier section (372) relative to the direction of movement (B) of the stop element (35) when it hits the barrier section (372) is in a range between 80° and 100° and / or - the angle between the barrier section (372) and the deflection section (371) is less than 90°, i.e. an acute angle. [4] Tensioner drive (30) according to one of the preceding claims, characterized by that the ramp has a flat ramp surface (371a) which is inclined relative to the direction of movement (B) immediately before reaching the stop device (37) at an angle of inclination between 30° and 60°. [5] Tensioner drive (30) according to one of the preceding claims, characterized by that the ramp has a ramp surface (371b) curved in the direction of the drive wheel (34). [6] Tensioner drive (30) according to one of the preceding claims, characterized by that the stop element (35) has a projecting nose portion (351) and a radially outer and rearwardly offset ring portion (352). [7] Tensioner drive (30) claim 6, characterized by , that - when the stop element (35) hits the stop device (37), the nose section (351) first hits the deflection section (371) and is guided by it in the direction of the drive wheel (34) and - the ring section (352) then hits the barrier section (372) and is stopped by it. [8] Tensioner drive (30) according to one of the preceding claims 6 to 7, characterized by that the projecting nose portion (351) is conical. [9] Tensioner drive (30) according to one of the preceding claims, characterized by that the thrust body (33) is a strand-shaped element, in particular a thrust body rod, which is plastically and / or elastically bent by the stop device (37) after passing the outlet opening (A32) of the feed pipe (32). [10] Tensioner drive (30) according to one of the preceding claims, characterized by that a front section of the thrust body (33) already rests on the stop device (37), in particular its deflection section (371), before the ignition of the gas generator (31). [11] Tensioner drive (30) according to one of the preceding claims, characterized by , that - the stop element (35) is not sealing with respect to the supply pipe (32) itself and a sealing element (36) is arranged in the supply pipe (32) between the gas generator (31) and the stop element (35) and - the distance between the outlet opening (A32) of the feed pipe (32) and the stop device (37) is smaller than the sum of the length - seen in the direction of movement (B) - of the stop element (35), the length of the sealing element (36) and - if present - the length of any intermediate elements located between the sealing element (36) and the stop element (35). [12] Tensioner drive (30) according to one of the preceding claims, characterized by , that - the stop element (35) is not sealing against the supply pipe (32) itself and a sealing element (36) resting against the stop element (35) is arranged between the gas generator (31) and the stop element (35) and - the distance between the outlet opening (A32) of the feed pipe (32) and the stop device (37) is smaller than the sum of the length - seen in the direction of movement (B) - of the stop element (35) and the length of the sealing element (36) located in front of it. [13] Tensioner drive (30) according to one of the preceding claims 1 to 10, characterized by , that - the stop element (35) is self-sealing relative to the feed pipe (32) and - the distance between the outlet opening (A32) of the feed pipe (32) and the stop device (37) is smaller than the length - seen in the direction of movement (B) - of the sealing stop element (35).

Images