Tensioner assembly for a belt tensioner and method of manufacturing a tensioner assembly

Abstract

The application presents a tensioner assembly (10) for a belt tensioner, comprising a tensioner tube (12) and a micro gas generator (14) arranged at least partially in the tensioner tube (12), the micro gas generator having a holder (16), an ignition unit (18) and an explosion charge container (20) filled with an explosion charge (22), wherein the tensioner tube (12) has a support (30) against which the micro gas generator (14) rests, wherein the tensioner tube (12) has a radially inwardly crimped section (32) by which the micro gas generator (14) is held in the tensioner tube (12), and wherein the micro gas generator (14) is girdled, wherein the crimped section (32) of the tensioner tube (12) is arranged in the girdled region of the micro gas generator (14). Furthermore, a method for producing a tensioner assembly is presented.

Description

Technical Field

[0001] The present invention relates to a tensioner assembly with a tensioner and a method for manufacturing the tensioner assembly. Background Technology

[0002] A belt tensioner is known in which a miniature gas generator installed in a tensioning tube is activated when needed to generate pressurized gas. Here, the pressurized gas is transmitted within the tensioning tube and, for example, drives a turbine connected to a shaft of a belt retractor to tighten the slack portion of the belt.

[0003] For the tensioner to function optimally, the miniature gas generator must be assembled into the tensioning tube with a fully pressure-sealed fit. For this purpose, the miniature gas generator is typically welded to the tensioning tube. However, such tensioner assemblies are costly to manufacture. Summary of the Invention

[0004] The object of this invention is to provide a tensioner assembly optimized in terms of overpressure stability and manufacturing cost.

[0005] According to the invention, this object is achieved by a tensioner assembly for use with a tensioner, the tensioner assembly comprising a tensioning tube and a miniature gas generator at least partially disposed in the tensioning tube, the miniature gas generator having a retainer, an ignition unit, and a deflagration packing container filled with deflagration packing, wherein the tensioning tube has a support portion against which the miniature gas generator abuts, and wherein the tensioning tube has a radially inwardly rolled section by which the miniature gas generator is retained in the tensioning tube, and wherein the miniature gas generator is waisted, wherein the rolled section of the tensioning tube is disposed in the waisted region of the miniature gas generator.

[0006] This type of tensioner assembly offers the advantage that the miniature gas generator is reliably and sufficiently pressure-sealed within the tensioning tube. Furthermore, the tensioner assembly can be manufactured simply and cost-effectively. Additionally, the tensioning tube can function as a load-bearing component when the miniature gas generator is activated. Here, with the miniature gas generator activated, the effective diameter of the pressure inside the tube decreases, which in turn has a beneficial effect on overpressure stability.

[0007] Because the rolled section of the tension tube is arranged within the waist-shaped area of ​​the miniature gas generator, the miniature gas generator is shape-fitted and fixed to the tension tube and cannot be released from it without being damaged. The rolled section of the tension tube is, for example, arranged between the ignition unit and the retainer.

[0008] Another advantage is that the retainer can be made of plastic because no high temperatures are generated when the tension tube is formed, as might be the case during welding.

[0009] The support portion against which the miniature gas generator rests (especially due to the narrowing of the pipe diameter) is spaced apart from the free end of the tensioning tube. In particular, the end of the miniature gas generator located on the end side within the tensioning tube can rest against this support portion.

[0010] Preferably, one end of the tensioning tube is radially inwardly rolled. In principle, the region of the tensioning tube spaced apart from the end can also be shaped inward, for example, as a radially inwardly extending, particularly annular, stamped portion. However, it is technically simpler to implement the rolled section on the end of the tensioning tube.

[0011] The waist section is formed, for example, by a conical segment of the ignition unit. The rolled edge segment of the tension tube can be flush with the conical segment. This achieves a good seal between the miniature gas generator and the tension tube, eliminating the need for complex geometry at the connection point.

[0012] The ignition unit is preferably connected to the retainer. According to one embodiment, the miniature gas generator can be pre-assembled as a component. This simplifies the manufacturing process. Alternatively, the deflagration filler container and the ignition unit, along with the retainer, can exist as separate components or assemblies before being assembled into the tensioning tube. According to another embodiment, the connection between the ignition unit and the retainer can be established during the crimping of the tensioning tube. This achieves the advantage of reliably connecting the retainer to the tensioner assembly, requiring only fewer manufacturing steps.

[0013] According to one embodiment, the ignition unit and the retainer are connected by a sleeve, the sleeve abutting against a conical section of the ignition unit.

[0014] Here, the ignition unit and / or the retaining member can be connected to the sleeve by force fit, form fit, or by means of adhesive connection. For example, the sleeve is clamped onto the conical section of the ignition unit.

[0015] The sleeve is preferably formed into a deflagration packing container. This allows for a smaller number of required components, thus enabling cost-effective manufacturing of the tensioner assembly.

[0016] According to a preferred embodiment, the sleeve has a radially inwardly oriented, circumferential stamped portion that forms a support for the ignition unit. This makes assembling, and especially positioning, the ignition unit within the sleeve particularly simple. The ignition unit can be easily pushed into the sleeve until it contacts the stamped portion.

[0017] To improve the seal between the sleeve and the ignition unit, an O-ring can be placed against the stamped portion on the inside of the sleeve. The O-ring is particularly positioned between the stamped portion and the ignition unit.

[0018] In an alternative embodiment, a retaining element may be provided on the retainer to connect the ignition unit to the retainer. The retaining element is, for example, a locking element that engages with the ignition unit, particularly around a widened section of the ignition unit, and thereby shape-fits the ignition unit to the retainer. In this embodiment, the sleeve can be omitted.

[0019] Furthermore, according to the present invention, this objective is achieved by a method for manufacturing a tensioner assembly with a tensioner, the tensioner assembly comprising a tensioning tube and a micro gas generator, wherein the micro gas generator has a retainer, an ignition unit, and a deflagration packing container filled with deflagration packing, the method comprising the following steps:

[0020] a) Connect the ignition unit to the retaining member.

[0021] b) Push the deflagration packing container, the ignition unit, and the retaining member into the tensioning tube.

[0022] c) Shape the tension tube so that the micro gas generator is securely held in the tension tube.

[0023] This method enables a pressure-sealed connection between the micro gas generator and the tensioning tube, where the manufacturing of the tensioner assembly is simple and cost-effective.

[0024] To further simplify the manufacturing process, especially to reduce the number of required process steps, steps a) and c) can be performed simultaneously, wherein the ignition unit is connected to the retainer by forming the tension tube. Attached Figure Description

[0025] Further advantages and features of the invention will become apparent from the following description and the following drawings, with reference to these drawings. In the drawings:

[0026] - Figure 1 A first embodiment of the tensioner assembly according to the present invention is shown, and

[0027] - Figures 2 to 5 Another embodiment of the tensioner assembly according to the invention is shown. Detailed Implementation

[0028] Figure 1A cross-sectional view is shown of a tensioner assembly 10 with a tensioner. The tensioner assembly 10 includes a tension tube 12 that guides gas upon triggering and a miniature gas generator 14 at least partially mounted within the tension tube 12. The miniature gas generator 14 has a retainer 16, an ignition unit 18, and a deflagration packing container 20 filled with deflagration packing 22, which generates pressurized gas upon triggering. In the illustrated embodiment, the deflagration packing container 20 is a sleeve 24 (particularly made of metal). A pin-shaped electrical contact 17 is provided on the retainer 16.

[0029] The sleeve 24 has a radially inwardly oriented, circumferential (especially annular) stamped portion 26. The stamped portion 26 forms a support for the ignition unit 18 and is therefore used to position the ignition unit 18 within the sleeve 24. For better sealing, an O-ring 28 abuts against the stamped portion 26 on the inside of the sleeve 24, particularly between the stamped portion 26 and the ignition unit 18.

[0030] The tensioning tube 12 has a support portion 30, against which the miniature gas generator 14 is attached. The support portion 30 is formed by a narrowing section in the pipe diameter, wherein the diameter of the tensioning tube 12 at the narrowing section is smaller than the diameter of the miniature gas generator 14.

[0031] In order to secure the miniature gas generator 14 within the tension tube 12, the tension tube 12 has a radially inwardly rolled section 32, particularly in the region where the miniature gas generator 14 is waisted. In particular, the tension tube 12 has a radially inwardly rolled edge at one end.

[0032] The waisted region of the miniature gas generator 14 is located at the transition from the ignition unit 18 to the retainer 16. The ignition unit 18 has a tapered section 34 that narrows radially inward toward the retainer 16 and thus forms the waisted region.

[0033] In the illustrated embodiment, the retainer 16 is segmentally attached to the ignition unit 18, particularly to the tapered segment 34 of the ignition unit 18. For this purpose, the retainer 16 has at least a segmentally surrounding flange 36 that widens in the longitudinal direction of the tension tube 12 at the same angle as the tapered segment 34.

[0034] The retainer 16 and the ignition unit 18 are connected to each other through both the sleeve 24 and the rolled section 32 of the tension tube 12.

[0035] During the manufacture of the tensioner assembly 10, for example, the deflagration filler container 20, the ignition unit 18, and the retainer 16 are pushed into the tension tube 12. The tension tube 12 is then shaped at its end such that a rolled section 32 is formed, which abuts against the tapered section 34 of the ignition unit 18; and the micro gas generator 14 is securely held in the tension tube 12.

[0036] The sleeve 24 can also be formed simultaneously during the formation of the tension tube 12. However, alternatively, the sleeve 24 can be formed before the tension tube 12 is formed, and in particular, the micro gas generator is then pushed into the tension tube, thereby forming the micro gas generator 14 into a pre-assembled, easy-to-operate assembly.

[0037] Figure 2 A cross-sectional view illustrates another embodiment of the tensioner assembly 10 according to the present invention.

[0038] For the same structures with the same functions known from the above embodiments, the same reference numerals are used below and reference is made to the preceding description, wherein the differences between the corresponding embodiments will be discussed below to avoid repetition.

[0039] Unlike Figure 1 The embodiments shown are based on Figure 2 In this embodiment, the sleeve 24 is extended and extends beyond the ignition unit 18 to the end of the retainer 16, that is, the sleeve 24 ends flush with the retainer 16. Here, the retainer 16 may be fixed in the sleeve 24 by force fit, form fit, or by means of adhesive and connected to the ignition unit 18 in this way.

[0040] Figure 3 A cross-sectional view illustrates another embodiment of the tensioner assembly 10 according to the present invention.

[0041] Unlike Figure 2 In the embodiment shown, the sleeve 24 is open at both ends. Thus, the sleeve 24 can be pre-manufactured with an internal contour for accommodating the ignition unit 18 and the retainer 16.

[0042] In order to create a basis Figure 3 The miniature gas generator 14 pushes the ignition unit 18 and O-ring 28 from the front into the sleeve 24, particularly through the end of the sleeve 24 that is positioned in the tension tube 12 after assembly. The sleeve 24 is then formed from the outside, holding the ignition unit 18 in place and sealing the miniature gas generator 14 by means of the O-ring 28. The sleeve is then filled with deflagration packing 22.

[0043] At the end of sleeve 24 that is oriented away from retainer 16, particularly at the end of micro gas generator 14 that is disposed in tension tube 12, sleeve 24 is sealed by rupture bottom 38. In the event of a triggering condition, this rupture bottom can rupture and pressurized gas can flow through tension tube 12.

[0044] Figure 4 A cross-sectional view illustrates another embodiment of the tensioner assembly 10 according to the present invention.

[0045] Unlike the embodiments described above, the deflagration packing 22 is filled in a separate, closed deflagration packing container 20.

[0046] Before assembling the ignition unit 18 onto the tension tube 12, the deflagration packing container 20 is inserted into the tension tube 12.

[0047] Here, the sleeve 24 is used only to connect the ignition unit 18 and the retainer 16. The profile of the sleeve 24 is adapted to the outer profiles of the ignition unit 18 and the retainer 16. The sleeve 24 surrounds the ignition unit 18 in such a way that the ignition unit is shaped to fit the sleeve 24. For this purpose, the end of the sleeve 24 surrounding the ignition unit 18 is radially inwardly shaped.

[0048] Sleeve 24 can be pre-manufactured largely according to its internal contour. After the ignition unit 18 is assembled into sleeve 24, the free end of sleeve 24 is shaped to secure the ignition unit 18.

[0049] Figure 5 A cross-sectional view illustrates another embodiment of the tensioner assembly 10 according to the present invention.

[0050] According to this embodiment, the retainer 16 has retaining elements 40 for interconnecting the ignition unit 18 and the retainer 16. The retaining elements 40 are in particular locking or clamping elements that at least partially engage around the ignition unit 18 and thereby form-fittingly secure the ignition unit 18 to the retainer 16. In this embodiment, the sleeve can be omitted.

[0051] The retainer 16 is, for example, a plastic injection molded part, wherein the retaining element 40 is integrally formed with the retainer 16.

Claims

1. A tensioner assembly (10) with a tensioner, the tensioner assembly comprising a tension tube (12) and a miniature gas generator (14) at least partially disposed in the tension tube (12), the miniature gas generator having a retainer (16), an ignition unit (18), and a deflagration packing container (20) filled with deflagration packing (22). The tensioning tube (12) has a support (30), and the micro gas generator (14) is attached to the support. The tension tube (12) has a radially inwardly rolled section (32) by means of which the micro gas generator (14) is held in the tension tube (12), and wherein The micro gas generator (14) is waisted, wherein the rolled section (32) of the tension tube (12) is arranged in the waisted region of the micro gas generator (14), and the waist is formed by the conical section (34) of the ignition unit (18).

2. The tensioner assembly (10) according to claim 1, characterized in that, The ignition unit (18) is connected to the retaining member (16).

3. The tensioner assembly (10) according to claim 2, characterized in that, The ignition unit (18) and the retainer (16) are connected by a sleeve (24), which abuts against the conical section of the ignition unit (18).

4. The tensioner assembly (10) according to claim 3, characterized in that, The ignition unit (18) and / or the retainer (16) are respectively connected to the sleeve (24) by force, form, or by means of adhesive connection.

5. The tensioner assembly (10) according to claim 3 or 4, characterized in that, The sleeve (24) forms the deflagration packing container (20).

6. The tensioner assembly (10) according to claim 3 or 4, characterized in that, The sleeve (24) has a radially inwardly oriented, circumferential stamped portion (26) that forms a support for the ignition unit (18).

7. The tensioner assembly (10) according to claim 6, characterized in that, On the inner side of the sleeve (24), the O-ring (28) abuts against the stamping part.

8. A method for manufacturing a tensioner assembly (10) with a tensioner according to claim 1, the tensioner assembly comprising a tensioning tube (12) and a micro gas generator (14), wherein the micro gas generator (14) has a retainer (16), an ignition unit (18), and a deflagration packing container (20), the deflagration packing container being filled with deflagration packing (22), the method comprising the steps of: a) Connect the ignition unit (18) to the retaining member (16), b) Push the deflagration packing container (20), the ignition unit (18), and the retaining member (16) into the tensioning tube (12). c) Shape the tension tube (12) such that the micro gas generator (14) is securely held in the tension tube (12).

9. The method according to claim 8, characterized in that, Steps a) and c) are performed simultaneously, wherein the ignition unit (18) is connected to the retainer (16) by forming the tension tube (12).

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