Method for mounting actuator assembly and airbag module comprising actuator assembly mounted thereon

Abstract

The invention relates to an airbag module (16) of a vehicle safety system and to a method of mounting an actuator assembly (10) for releasing a traction device (12) on a module housing (14) of the airbag module (16), comprising the steps of: a) connecting the traction device (12) to the actuator assembly (10) and fixing the traction device (12) together with the actuator assembly (10) to a mounting element (18), such that the pulling device (12), the actuator assembly (10) and the mounting element (18) form a pre-mounted unit (20); b) arranging the pre-installed unit (20) inside the module housing (14) and fastening the pre-installed unit (20) to the module housing (14) by means of an installation element (18).

Description

Technical Field

[0001] The present invention relates to an airbag module of a vehicle safety system comprising a module housing and an actuator assembly mounted on the module housing, and to a method of mounting the actuator assembly for releasing a pulling device on the module housing of the airbag module. Background Art

[0002] In engineering, for example in vehicle safety engineering, explosive bolts are used as actuator components. Typically they are very strong metal parts that are fastened via threads and are able to absorb very large forces. The release energy required for said explosive bolts is correspondingly high, so that they can, for example, expose housing holes, displace components (sometimes against compressive forces) or cut themselves off.

[0003] In modern vehicle safety systems, in particular in airbag modules, efforts are being made to adapt the safety systems more and more individually to the different parameters of a crash situation. In this respect, a known and advantageous option is to use a pulling device, such as a tether, which, by releasing it, opens or closes the discharge opening. The pulling device can also be used to alternatively or additionally influence the airbag geometry and / or release additional airbag volume.

[0004] For active release of the tether, a so-called tether release unit "TAU" is required. The TAU is usually subjected to shear stresses by relatively low transverse force loads. Conventional explosive bolts are usually oversized and too expensive for this application.

[0005] Therefore, in the prior art, actuator assemblies for active tether release have been proposed which have a plastic housing and can be manufactured at low cost.

[0006] It is further known to provide a restraint device in an airbag module comprising such an actuator assembly, which restricts the free mobility of the fragments detached after actuation of the actuator assembly. In this way, undesired contact with a vehicle occupant or damage to the airbag module by the detached fragments is largely excluded.

[0007] For example, DE 10 2008 028 921 A1 shows an airbag module comprising an actuator assembly for releasing a tether, wherein the actuator assembly is mounted in a stable generator housing of the airbag module and breaks into a fixed fastening part and at least one separated fragment when it is actuated. In order to limit the free mobility of the separated fragment, a restraining device, in particular a receiving cage for the separated fragment formed by the generator housing, is provided.

[0008] However, it has proven that fastening the tensioning device in the form of a TAU to the actuator assembly and in particular mounting the TAU on the airbag module requires complex structural changes (eg on the gas generator) and / or is very time-consuming and therefore expensive for the fitter. Summary of the invention

[0009] The object of the present invention is therefore to provide an airbag module comprising an actuator assembly for releasing a pulling device, which actuator assembly is low-cost, compact and easy to manufacture and meets all existing safety requirements for pyrotechnic actuators with movable parts or fragments and can moreover be easily mounted on an airbag module of a vehicle safety system.

[0010] According to the present invention, this object is achieved by a method for mounting an actuator assembly for releasing a pulling device on a module housing of an airbag module, comprising the following steps:

[0011] a) connecting the pulling device to the actuator assembly and fixing it together with the actuator assembly to the mounting element, so that the pulling device, the actuator assembly and the mounting element constitute a pre-mounted unit;

[0012] b) The pre-mounted unit is arranged inside the module housing and fastened to the module housing by means of mounting elements.

[0013] In the described mounting method, the module housing of the airbag module is not required for fixing the tensioning device to the actuator assembly, so that pre-assembly in method step a) can be performed quickly and easily. Incidentally, since the pre-assembly unit is not arranged and fixed outside the module housing (as is usually the case) but inside the module housing, the tensioning device does not need to be passed through a slit or perforation in the module housing in order to be fixed to the actuator assembly. This also contributes to a particularly quick and easy mounting of the actuator assembly on the module housing of the airbag module.

[0014] According to a method variant, the pulling device is already fastened to the airbag of the airbag module before step a). In this way, the pulling device, which is usually provided in the form of a tether, can already be easily fastened to the airbag during manufacture of the airbag, in particular sewn or glued to the airbag wall.

[0015] Preferably, the pulling device forms a ring into which the actuator assembly is inserted in step a) in order to connect the pulling device to the actuator assembly. For this purpose, the actuator assembly, in particular the bursting part of the actuator assembly, comprises, for example, a groove-shaped predetermined breaking point in which the pulling device engages.

[0016] According to another method variant, in step a), the pulling means is firstly guided through an opening in the mounting element and subsequently connected to the actuator assembly. The pulling means is in particular a tether, a rope, a cord or the like.

[0017] In step a), the actuator assembly is preferably locked with the mounting element to form a pre-mounted unit. By locking, the pulling device can be fastened to the actuator assembly very quickly, while forming a pre-mounted unit, wherein the correct position of the pulling device can be easily checked and no laborious checking is required at a later stage of the mounting method.

[0018] Particularly preferably, the pre-mounted unit is locked with the module housing in step b). This locking connection allows the pre-mounted unit to be mounted very quickly and also ensures a particularly secure fastening to the module housing. Since the module housing and the pre-mounted unit, in particular the mounting elements of the pre-mounted unit, are usually made of synthetic material, suitable locking elements can be constructed in a simple and cost-effective manner with little manufacturing effort.

[0019] According to a further method variant, the mounting element comprises a mounting flange, and the module housing comprises a guide element for the mounting flange, which mounting flange is inserted into the guide element in step b) until the pre-mounted unit reaches the final mounting position. The final mounting position is defined, for example, by a stop formed at the guide element or at the module housing. Such a sliding seat contributes to particularly reliable and permanent anchoring of the pre-mounted unit to the module housing, and only forces acting opposite to the insertion direction can remove the pre-mounted unit from its final mounting position.

[0020] In this method variant, the mounting element can be locked together with the module housing in the final mounting position. In this way, even if a force acting against the insertion direction is applied, it can be easily ensured that the pre-mounted unit will not detach from the module housing.

[0021] According to another method variant, the actuator assembly comprises an electrical ignition unit, wherein, according to step b), the electrical connector is passed from the outside of the module housing through a recess of the module housing and connected to the ignition unit. In this way, the electrical connection of the actuator assembly can be quickly and easily achieved after the actuator assembly has been installed in the airbag module. Incidentally, the prefabricated airbag module can be safely transported and can be easily connected to the electrical vehicle system only after installation in the vehicle.

[0022] Incidentally, the invention also includes an airbag module of a vehicle safety system, comprising: an airbag for restraining a vehicle occupant; a gas generator for filling the airbag with a generator gas; a module housing for receiving a folded airbag and / or a gas generator; and an actuator assembly for releasing a tether, the actuator assembly being mounted on the module housing in particular according to the aforementioned method by means of a mounting element, wherein the actuator assembly comprises a bursting part, which is connected to a pulling device and, after actuation of the actuator assembly, breaks and forms at least one scattered fragment, wherein the mounting element forms a restraint cage for at least one scattered fragment. Although the actuator assembly is arranged in the module housing, the restraint cage formed by the mounting element ensures in a simple manner that the free mobility of the fragments separated after actuation of the actuator assembly is limited. In this way, damage to the airbag equally arranged in the module housing by the separated fragments is largely excluded.

[0023] According to a preferred embodiment, the module housing is pot-shaped or trough-shaped, and the mounting element is arranged inside the module housing.

[0024] Furthermore, the actuator assembly is preferably a pyrotechnic actuator assembly comprising an electrical ignition unit.

[0025] Finally, the module housing can include a recess for the electrical connector, wherein the electrical ignition unit abuts on the recess. In this way, the actuator assembly can be easily electrically connected via the plug connector. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features and advantages of the present invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings, in which:

[0027] Figure 1 A detailed view of an airbag module according to the invention in the region of a tensioning device pre-mounted on an airbag is shown;

[0028] Figure 2 Shown according to Figure 1 A detailed view of an airbag module, wherein additional mounting elements are provided;

[0029] Figure 3 Shown according to Figure 2 A detailed view of an airbag module, wherein an actuator assembly connected to a pulling device is additionally provided;

[0030] Figure 4 Shown according to Figure 3 A detailed view of an airbag module, wherein the tensioning device, the actuator assembly and the mounting element form a pre-mounted unit;

[0031] Figure 5Shown according to Figure 4 Detailed view of the pre-installed unit;

[0032] Figure 6 The airbag module according to the present invention is shown in FIG. Figure 5 Detailed view of the pre-assembled unit at the beginning of installation into the module housing;

[0033] Figure 7 Shown according to Figure 6 The airbag module is installed according to Figure 5 Detailed view during the pre-installation unit;

[0034] Figure 8 Shown according to Figure 6 The airbag module is installed according to Figure 5 A detailed view of the pre-installed unit; and

[0035] Fig. 9 Shown according to Figure 8 Another detailed view of the airbag module. DETAILED DESCRIPTION

[0036] Figures 1 to 8 The installation of an actuator assembly 10 for releasing a pull device 12 on a module housing 14 of an airbag module 16 for a vehicle safety system is shown.

[0037] In the installation method shown in the figure, according to Figures 1 to 4 The pulling device 12 is first connected to the actuator assembly 10 and fixed to the mounting element 18 together with the actuator assembly 10, so that the pulling device 12, the actuator assembly 10 and the mounting element 18 constitute a Figure 5 Pre-installed unit 20.

[0038] In the subsequent method steps, according to Figures 6 to 8 The pre-mounted unit 20 is arranged inside the module housing 14 and is fastened to the module housing 14 by means of mounting elements 18 .

[0039] In addition to the general installation procedure described, advantageous details of the illustrated method variant will be discussed below.

[0040] according to Figure 1 The tensioning device 12 is already fastened to the schematically indicated airbag 22 of the airbag module 16 at the beginning of the installation method. The tensioning device 12 is in particular in the form of a tether, a rope or a cord and can already be connected, in particular sewn or glued, to the airbag wall in this way during the manufacture of the airbag 22.

[0041] As from Figure 2As is apparent in the drawing, the pulling device 12 is first passed through the opening 24 in the mounting element 18 and is subsequently connected to the actuator assembly 10. In the exemplary embodiment, the opposite ends of the pulling device 12 are fastened to the airbag 22 so that the pulling device 12 forms a loop 26, and the actuator assembly 10 is connected according to the embodiment of the present invention. Figure 3 Inserted into the loop 26 in order to connect the pulling device 12 to the actuator assembly 10 .

[0042] The actuator assembly 10 is in particular a pyrotechnic actuator assembly, which comprises an electric ignition unit 28 and an assembly housing 30, preferably made of synthetic material. The assembly housing 30 receives the electric ignition unit 28 and defines a combustion chamber filled with pyrotechnic material in its interior. The actuator assembly 10, in particular its assembly housing 30, comprises a bursting part 32 connected to the pulling device 12 in the region of the combustion chamber and will break and form at least one scattered fragment after actuation of the actuator assembly 10.

[0043] The mounting element 18 (together with the module housing 14 , in particular the bottom of the module housing 14 ) forms a containment cage 35 for at least one loose fragment, in order to prevent the adjacent airbag 22 from being damaged by the detached fragment.

[0044] according to Figure 3 , the bursting part 32 of the actuator assembly 10 comprises a groove-shaped predetermined breaking point, in which the pulling device 12 engages. When the actuator assembly 10 is actuated, the pyrotechnic material present in the combustion chamber is ignited by the electric ignition unit 28 and generates a sufficiently high internal pressure, so that the actuator assembly 10, in particular its assembly housing 30, ruptures at the groove-shaped predetermined breaking point, so that the pulling device 12 stored there will be released.

[0045] according to Figure 3 After the pulling device 12 is connected to the actuator assembly 10, according to Figure 4 The actuator assembly 10 is locked with the mounting element 18 to form a pre-mounted unit 20. For this purpose, a flexible locking element 33 is provided at the assembly housing 30 of the actuator assembly 10, which is adapted to be locked with a corresponding locking portion of the mounting element 18.

[0046] In this manner, the actuator assembly 10 may be quickly and easily clipped into the mounting element 18, thereby securing the pulling device 12 to the actuator assembly 10 and securing the actuator assembly 10 to the mounting element 18 at a desired mounting location in a secure and captive manner.

[0047] Figure 5 The pre-assembly unit 20 shown in FIG. 1 can thus be quickly and easily mounted on the module housing 14 , wherein the pre-assembly unit 20 is in particular locked with the module housing 14 according to the method variant.

[0048] according to Figure 5 , the mounting element 18 has opposing mounting flanges 34 for fastening the pre-mounted unit 20 in the module housing 14. In addition, according to Figure 6 The module housing 14 comprises a guide element 36 for mounting the flange 34, wherein according to Figure 7 The mounting flange 34 is inserted into the guide element 36 until the pre-mounted unit 20 reaches the position according to Figure 8 The final installation position is defined, for example, by a stopper formed at the guide element 36 or at the module housing 14 .

[0049] In the illustrated variant of the mounting method, the mounting element 18 is locked with the module housing 14 according to Figure 8 To this end, a corresponding locking portion 40 (see FIG. 1 ) is formed at the mounting element 18 and can engage with the module housing 14. Fig. 9 ) interacting elastic locking elements 38.

[0050] By inserting the mounting flange 34 into the guide element 36, the pre-mounted unit 20 and the module housing 14 can be easily and permanently and reliably connected. The locking in the final mounting position prevents the pre-mounted unit 20 from being moved against the guide element 36. Figure 7 42 shown in the insertion direction 42 and disengagement from the module housing 14. Thus, this quick and easy installation ensures reliable fixation of the pre-mounted unit 20 in its final installation position even in the event of, for example, high loads (e.g., when actuating the actuator assembly).

[0051] Fig. 9 Shown according to Figure 8 1 shows a perspective external view of the airbag module 16 in the region in which the actuator assembly 10 is mounted. It is apparent that the module housing 14 comprises a recess 44 for a schematically illustrated electrical connector 46 , wherein the electrical ignition unit 28 of the actuator assembly 10 abuts on the recess 44 .

[0052] After the actuator assembly 10 is installed in the module housing 14, the airbag module 16 can be completed as a supplier component and safely shipped. Only at a later stage, for example when the airbag module 16 is installed in a vehicle, the electrical connector 46 can be passed through the recess 44 from the outside of the module housing 14 and can be connected to the electrical ignition unit 28. Thus, the electrical connection of the actuator assembly 10 can be directly realized by a simple plug connection.

[0053] By the above installation of the actuator assembly 10 on the module housing 14, an airbag module 16 of a vehicle safety system is formed, the airbag module comprising: an airbag 22 for restraining a vehicle occupant; a gas generator 48 for filling the airbag 22 with a generator gas, such as Figure 6 ; a module housing 14 for receiving a folded airbag 22 and / or a gas generator 48; and an actuator assembly 10 for releasing the pulling device 12, which has been mounted on the module housing 14 by means of a mounting element 18 according to the aforementioned method. The actuator assembly 10 comprises a bursting portion 32, which is connected to the pulling device 12 and breaks after actuating the actuator assembly 10 and forms at least one scattered fragment, wherein the mounting element 18 forms a restraining cage 35 for at least one scattered fragment.

Claims

1. A method for mounting an actuator assembly (10) for releasing a pulling device (12) on a module housing (14) of an airbag module (16), comprising the following steps: a) connecting the pulling device (12) to the actuator assembly (10) and fixing it together with the actuator assembly (10) to a mounting element (18), so that the pulling device (12), the actuator assembly (10) and the mounting element (18) constitute a pre-mounted unit (20); b) Arranging the pre-mounted unit (20) inside the module housing (14) and fastening it to the module housing (14) by means of the mounting element (18).

2. The method according to claim 1, characterized in that: Prior to step a), the pulling device (12) is fastened to the airbag (22) of the airbag module (16).

3. The method according to claim 1 or 2, characterized in that: The pulling device (12) forms a loop (26) into which the actuator assembly (10) is inserted in step a) in order to connect the pulling device (12) to the actuator assembly (10).

4. The method according to any one of the preceding claims, characterized in that In step a), the pulling device (12) is first guided through an opening in the mounting element (18) and subsequently connected to the actuator assembly (10).

5. The method according to any one of the preceding claims, characterized in that In step a), the actuator assembly (10) is locked with the mounting element (18) so as to form the pre-mounted unit (20).

6. The method according to any one of the preceding claims, characterized in that In step b), the pre-installed unit (20) is locked with the module housing (14).

7. The method according to any one of the preceding claims, characterized in that The mounting element (18) comprises a mounting flange (34), and the module housing (14) comprises a guide element (36) for the mounting flange (34), wherein, in step b), the mounting flange (34) is inserted into the guide element (36) until the pre-mounted unit (20) reaches a final mounting position.

8. The method according to claim 7, characterized in that In the final installation position, the installation element (18) is locked with the module housing (14).

9. The method according to any one of the preceding claims, characterized in that The actuator assembly (10) includes an electric ignition unit (28), wherein after step b), an electrical connector (46) passes through a recess (44) of the module housing (14) from outside the module housing (14) and is connected to the electric ignition unit (28).

10. An airbag module of a vehicle safety system, comprising: an airbag (22) for restraining a vehicle occupant; a gas generator (48) for filling the airbag (22) with a generator gas; a module housing (14) for receiving the folded airbag (22) and / or the gas generator (48); and An actuator assembly (10) for releasing a pulling device (12), which is mounted on the module housing (14) by means of a mounting element (18), in particular according to the method of any of the preceding claims, wherein the actuator assembly (10) comprises a bursting portion (32) connected to the pulling device (12) and which will break and form at least one dispersed fragment after actuating the actuator assembly (10), and Therein, the mounting element (18) forms a containment cage (35) for the at least one loose fragment.

11. The airbag module according to claim 10, characterized in that: The module housing (14) is pot-shaped or trough-shaped, and the mounting element (18) is arranged inside the module housing (14).

12. The airbag module according to claim 10 or 11, characterized in that: The actuator assembly (10) is a pyrotechnic actuator assembly including an electrical ignition unit (28).

13. The airbag module according to claim 12, characterized in that: The module housing (14) comprises a recess (44) for an electrical connector (46), wherein the electrical ignition unit (28) abuts against the recess (44).

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