Tensioning device for a seat belt component

Description

[0001] The present invention relates to a tensioning device for a safety belt component, comprising a gas generator for generating a compressed gas, a piston which can be driven by the compressed gas, a pull cable which is connected to the piston and which can be connected to the safety belt component which is to be set in a tensioning movement, and a tensioning tube for receiving and guiding the piston.

[0002] Such a tensioning device is known, for example, from DE 10 2015 111 083 B4, in which the piston is guided in a tensioning tube. The tensioning tube is connected to a deflection block manufactured using a die-casting process, which forms a cable deflection for the traction cable as well as a receptacle for the gas generator and a pressure chamber into which the compressed gas generated by the gas generator flows. The deflection block, connected to the front of the tensioning tube, requires a relatively expensive component that also requires a relatively large amount of space.

[0003] The object of the present invention is therefore to at least partially eliminate the problems described with reference to the prior art and to provide a tensioning device and a method for producing a tensioning device, with which the production of a tensioning device is simplified and / or more cost-effective, wherein the tensioning device requires less space. A tensioning device having the features of the preamble of claim 1 is known from US 2014 / 0265288 A1.

[0004] This object is achieved by a tensioning device and a method having the features of the respective independent claim. Advantageous developments of the tensioning device and the method are specified in the dependent claims and in the description, with individual features of the advantageous developments being combinable with one another in a technically expedient manner.

[0005] The object is achieved in particular by a tensioning device with the features mentioned at the outset, in which the gas generator is arranged in the tensioning tube, the tensioning tube has a recess in its casing between the gas generator and the piston and a cable deflection is provided with which the traction cable is guided out of the tensioning tube through the recess.

[0006] The basic idea of ​​the invention is that the gas generator itself is located in the tensioner tube, and that the cable deflection begins in the tensioner tube itself, so that the traction cable is routed through the casing of the tensioner tube. This eliminates the need for a complex deflection block, which also saves space.

[0007] The gas generator is therefore arranged entirely within the tensioning tube, particularly with its section that emits the pressurized gas when triggered. In particular, the gas generator is arranged such that only its (electrical) connections are accessible from outside the tensioning tube. The gas generator is arranged, in particular, at one end of the tensioning tube, with the connections of the gas generator being accessible from the front side of the tensioning tube. In particular, it can be provided that the tensioning tube has a reduced diameter at the end receiving the gas generator, so that the gas generator is positively secured against removal on this side of the tensioning tube.

[0008] In the event of triggering, the piston is accelerated by the gas generated by the gas generator in the direction of the end of the tensioner tube opposite the gas generator, whereby the piston pulls the pull cable through the recess, for which purpose the recess is arranged in the casing of the tensioner tube between the gas generator and the piston.

[0009] To prevent the traction cable from directly contacting the tensioner tube in the area of ​​the recess in the event of a triggering event, at least one additional component is provided as a cable deflection device, which guides the traction cable to / through the recess in the tensioner tube, at least during the tensioning movement. The cable deflection device is designed in particular such that the traction cable is deflected from the essentially axially parallel orientation within the tensioner tube to an oblique (in particular orthogonal) orientation outside the tensioner tube. The traction cable therefore runs outside the tensioner tube at an angle to the tensioner tube.

[0010] In particular, it is provided that the recess in the tensioning tube is arranged in a rectilinear section of the tensioning tube, so that the traction cable runs outside the tensioning tube at an angle to this rectilinear section. In this context, it is preferred that the tensioning tube be rectilinear / linear over its entire extension, i.e., without any curvature along its longitudinal extension.

[0011] The cable deflection device is particularly constructed in two or more parts and comprises a guide part inserted into the tensioning tube and a fixing part extending from outside the tensioning tube through the recess. The guide part is thus designed, particularly with regard to its outer diameter and circumferential configuration, such that it can be inserted into the tensioning tube from one end of the tensioning tube during assembly of the tensioning device. The fixing part, on the other hand, is designed and matched to the recess in the tensioning tube such that a portion of it can be inserted into the recess from outside the tensioning tube, with a substantial portion of the fixing part preferably being formed outside the tensioning tube.

[0012] In a preferred embodiment, the guide part has a recess into which the fixing part engages with a projection. In this case, a shape of at least one section of the projection corresponds to a complementary shape of at least one section of the recess, so that the guide part and the fixing part can be precisely aligned with one another during assembly. In this case, the recess in the guide part is formed in a region of the guide part which, in the assembled state, faces the recess in the tensioner tube, while the projection is designed in particular such that, in the assembled state, it is arranged within the tensioner tube and, in particular, engages behind a section of the tensioner tube adjacent to the recess in the tensioner tube.

[0013] The guide part and the fixing part can each form a deflection for the traction cable, either individually or together, so that the traction cable is guided out of the tensioning tube in such a way that it cannot come into contact with the tensioning tube.

[0014] While it is in principle sufficient for the gas generator and the cable deflection to be mounted individually in / on the tensioning tube, it is preferred if the guide part of the cable deflection in particular has a receptacle in which the gas generator is arranged. In particular, the gas generator with its section that emits the compressed gas is arranged within the receptacle of the guide part. This means that the guide part can be used not only for deflecting the cable, the guide part and the fixing part can each form a deflection for the traction cable, individually or together, so that the traction cable is guided out of the tensioning tube in such a way that it cannot come into contact with the tensioning tube.

[0015] According to the invention, the guide part of the cable deflection device has a receptacle in which the gas generator is arranged. In particular, the gas generator, with its section that emits the compressed gas, is arranged within the receptacle of the guide part. This not only allows the guide part to be used for deflecting the cable, but also simultaneously provides a seal for the compressed gas, so that the compressed gas does not escape from the tensioner tube at unintended locations in the event of activation. Furthermore, this allows the gas generator to be pre-assembled in the guide part and the guide part and the gas generator to be arranged together in the tensioner tube during production.

[0016] It can also be provided that the guide part forms at least one compressed gas guide channel which extends along the extent of the tensioner tube to the piston-side end of the guide part. The compressed gas guide channels are in particular tubular (optionally curved) formed in the guide part and extend from an inlet facing the gas generator to an end of the guide part facing the piston. With the at least one compressed gas guide channel, the compressed gas escaping from the gas generator can therefore be guided in a targeted manner to the space between the guide part and the piston, without the pull cable in the area of ​​the guide part being exposed to the hot compressed gas.

[0017] In a preferred embodiment, the traction cable is first enclosed by a lip seal of the guide part, is then guided together through the projection of the fixing part and the deflection on the guide part to the recess and then further guided through the opening of the fixing part.

[0018] The section of the fixing part located outside the tensioner tube is held to the tensioner tube by means of a holder. The holder is particularly shaped such that it surrounds the outside of the tensioner tube and is attached to the fixing part at both ends. The holder can be attached to the fixing part using screws or rivets. It is also possible for the tensioning device to be attached to a motor vehicle in this area. The holder preferably has a U-shaped or keyhole-shaped cross-section.

[0019] To manufacture the tensioning device, a particularly straight tensioning tube is first prepared. The gas generator is then inserted into the tensioning tube. In this case, it can be provided that the gas generator is first pre-assembled in one element, particularly in the guide part of the cable deflection, and that the guide part and the gas generator are inserted together into the tensioning tube. The cable deflection is then fixed to the tensioning tube, for which purpose, in particular, the fixing part is inserted from the outside through the recess in the guide part. In addition, the fixing part can be secured in position on the tensioning tube by means of a holder.

[0020] The pull cable is then inserted into the tensioner tube and guided through the cable guide. The piston is then attached to the pull cable. However, the order of these steps is not important unless technically necessary.

[0021] The invention and the technical environment are explained below using the figures as examples. They show schematically Figure 1: a sectional view through a tensioning device, Figure 2: an exploded view of the tensioning device, Figure 3: a perspective view of a guide part of the tensioning device, Figure 4: a sectional view through the guide part, Figure 5: a perspective view of a fixing part of the tensioning device and Figure 6: a sectional view through the fixing part.

[0022] The Figures 1 and 2 The tensioning device shown comprises a tensioning tube 1 and a traction cable 8, at the end of which, arranged in the tensioning tube 1, a piston 4 is attached, which is fastened to the traction cable 8 by means of a fastening 6, wherein balls 5 enable low-friction guidance of the piston 4 in the tensioning tube 1. A recess 13 is formed in the casing of the tensioning tube 1.

[0023] The tensioning device also includes a cable deflection 14, by means of which the traction cable 8 is guided through the recess 13 in the tensioner tube 1. The cable deflection 14 includes a guide part 3, in whose receptacle 15, facing away from the piston 4, a gas generator 2 is arranged. The cable deflection 14 also includes a fixing part 9, which extends through the recess 13 in the tensioner tube 1 with a projection 19. The fixing part 9 is attached to the tensioner tube 1 by means of a holder 7 via a rivet 11 and a screw 12, with the holder 7 encompassing the outside of the tensioner tube 1.

[0024] As can be seen particularly from the overview of Figures 3 and 4 As can be seen, the guide part 3 has a receptacle 15 for the gas generator 2. In addition, the guide part 3 forms a plurality of compressed gas guide channels 17, which extend from the receptacle side to the end of the guide part 3 facing the piston 4.

[0025] The guide part 3 also forms a deflection 16 by means of which the traction cable 8 is fed to the recess 13 in the tensioner tube 1.

[0026] In addition, the overview of the Figures 3 to 6 It can be seen that the fixing part 9 has a projection 19 which, in the assembled state, engages in a recess 18 formed in the guide part 3.

[0027] When triggered, the gas generator 2 generates compressed gas, which is guided through the compressed gas guide channels 17 along the deflection 16, so that the hot compressed gas in the area of ​​the guide part 3 does not directly impact the pull cable 8. The guide part 3 is designed so that compressed gas can only escape from the guide part 3 along the compressed gas guide channels 17. The compressed gas escaping from the guide part 3 accelerates the piston 4 to the right in the figures, so that the pull cable 8 is pulled into the tensioner tube 1, whereby the cable deflection 14 prevents the pull cable 8 from coming into direct contact with the tensioner tube 1.

[0028] For simplified assembly, the gas generator 2 can first be inserted into the receptacle 15 of the guide part 3 and then pushed together with the guide part 3 into the tensioner tube 1. The guide part 3 is then fixed by means of the fixing part 9 by inserting the fixing part 9 with its projection 19 into the recess 18 of the guide part 3. The fixing part 9 is then secured to the tensioner tube 1 by means of the holder 7. In addition, the pull cable 8 is inserted through the cable deflection 14 into the tensioner tube 1, whereby the piston 4 can be fixed with the fastening 6 beforehand or afterwards. List of reference symbols

[0029] 1Tensioner tube 2Gas generator 3Guide part 4Piston 5Ball 6Fastener 7Holder 8Pull cable 9Fixing part 10Washers 11Rivet 12Screw 13Recess 14Cable deflection 15Receptacle 16Deflection 17Pressure gas guide channel 18Recess 19Protrusion

Claims

1. Tensioning device for a safety belt component, comprising - a gas generator (2) for generating a pressurized gas, - a piston (4) which can be driven by the pressurized gas, - a traction cable (8) which is connected to the piston (4) and can be connected to a safety belt component to be set into tensioning motion, and - a tensioner tube (1) for receiving and guiding the piston (4), wherein - the gas generator (2) is arranged in the tensioner tube (1), - the tensioner tube (1) has a cut-out (13) in the casing thereof between the gas generator (2) and the piston (4), and - a cable deflector (14) is provided, by means of which the traction cable (8) is guided out of the tensioning tube (1) through the cut-out (13), wherein the cable deflector (14) comprises a guide part (3) inserted into the tensioning tube (1) along the extension of the tensioning tube (1), characterized in that the guide part (3) has a receptacle (15) and wherein the gas generator (2) is arranged in the receptacle (15).

2. Tensioning device according to claim 1, wherein the guide part (3) has a deflection (16) for the traction cable (8), wherein the deflection (16) extends from the piston-side end of the guide part (3) to the cut-out (13) in the tensioner tube (1).

3. Tensioning device according to claim 1 or 2, wherein the guide part (3) forms at least one pressurized gas duct (17), wherein the pressurized gas duct (17) extends along the extension of the tensioner tube (1) to the piston-side end of the guide part (3).

4. Tensioning device according to any of the preceding claims, wherein the cable deflector (14) comprises a fixing part (9) which engages in the cut-out (13) of the tensioner tube (1) from outside the tensioner tube (1), wherein the traction cable (8) is guided through the fixing part (9).

5. Tensioning device according to claim 4, wherein the fixing part (9) is held on the tensioner tube (1) by a holder (7).

6. Tensioning device according to any of the preceding claims, wherein the cable deflector (14) is formed in two or more parts and has a guide part (3) which is inserted into the tensioner tube (1), and a fixing part (9) which engages through the cut-out (13) from the outside.

7. Tensioning device according to claim 6, wherein the guide part (3) has a recess (18) in which the fixing part (9) engages by means of a projection (19).

8. Tensioning device according to either claim 5 or claim 6, wherein the guide part (3) and the fixing part (9) form a deflection for the traction cable (8).

9. Tensioning device according to any of the preceding claims, wherein the cut-out (14) is arranged in a rectilinear portion of the tensioner tube (1).

10. Tensioning device according to any of the preceding claims, wherein the tensioner tube (1) is rectilinear over its entire extension.

11. Method for producing a tensioning device, comprising the following steps: a) providing a tensioner tube (1) which has a cut-out (13) in its casing, b) pre-assembling a gas generator (2) in a receptacle (15) of a guide part (3) of a cable deflector (14), c) inserting the guide part (3) of the cable deflector (14) with the preassembled gas generator (2) into the tensioner tube (1), d) fixing the cable deflector (14) to the tensioner tube (1), e) introducing a traction cable (8) into the tensioner tube (1), f) fastening a piston to the traction cable (8).