Pyrotechnical Actuator Unit, Method of Manufacturing the Same, and Gas Bag Module With Such Actuator Unit

• US 20090167006A1
• Filed: 12/08/2006
• Published: 07/02/2009
• Est. Priority Date: 12/08/2005
• Status: Active Grant

• Current Assignee: TRW Airbag Systems GmbH (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Airbag Systems GmbH (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Schõnhuber, Georg, Nuiding, Hannes, Enzmann, Ernst
• Granted Patent: US 8,083,259 B2
• Time in Patent Office: Days
• US Class Current: 280/741
• CPC Class Codes: B60R 2021/23386 External tether means
• CPC Class Codes: B60R 21/233 comprising a plurality of individual compartments; comprising two or more bag-like members, one within the other B60R21/232 takes precedence
• CPC Class Codes: B60R 21/26 characterised by the inflation fluid source or means to control inflation fluid flow arrangement or mounting thereof to the vehicle B60R21/20; blasting cartridges for producing gas under pressure in general F42B3/04; initiators or igniters therefor F42B3/10
• CPC Class Codes: F42B 3/006 Explosive bolts; Explosive actuators explosive valves F16K13/06; explosive cutting B23D15/145; explosive switches H01H39/00; pyrotechnical actuators F15B15/19

Abstract

The invention relates to a pyrotechnical actuator unit (10) for actuating a vehicle safety system, including a pyrotechnical igniter (12) and an outer housing (14) made of a plastic material accommodating the pyrotechnical igniter (12), the outer housing (14) breaking by activation of the igniter (12). The outer housing (14) is made up of a first plastic part (18) and a second plastic part (20), the two plastic parts (18, 20) being permanently connected with each other.

The invention further concerns a gas bag module having such an actuator unit (10), and a method of manufacturing a pyrotechnical actuator unit (10), including a pyrotechnical igniter (12) and an outer housing (14) accommodating the pyrotechnical igniter (12), the outer housing (14) being made up of a first housing part (48) and a second housing part (50), the method including the following method steps: The first housing part (48) is first produced to have a recess for the pyrotechnical igniter (12), followed by insertion of the pyrotechnical igniter (12) into the recess. Finally, the second housing part (50) is injection-molded onto the pyrotechnical igniter (12) and onto a first end (34) of the first housing part (48), so that a receiving space (24) for the pyrotechnical igniter (12) is essentially closed.

Claims

1. A pyrotechnical actuator unit for actuating a vehicle safety system, comprising a pyrotechnical igniter (12) and an outer housing (14) made of a plastic material accommodating the pyrotechnical igniter (12), the outer housing (14) breaking by an activation of the igniter (12), wherein the outer housing (14) is made up of a first plastic part (18) and a second plastic part (20), the two plastic parts (18, 20) being permanently connected with each other.

2. The pyrotechnical actuator unit according to claim 1, wherein the outer housing (14) has a pressure chamber (16) formed therein which is defined by the igniter (12), on the one hand, and by the outer housing (14), on the other hand.

3. The pyrotechnical actuator unit according to claim 2, wherein the igniter (12) and the first plastic part (18) define the pressure chamber (16).

4. The pyrotechnical actuator unit according to claim 2, wherein the pressure chamber (16) is provided in the area of a predefined breaking point (30) of the outer housing (14).

5. The pyrotechnical actuator unit according to claim 1, wherein the first plastic part (18) and the second plastic part (20) form a receiving space (24) in the outer housing (14), the receiving space (24) being at least partly occupied by the pyrotechnical igniter (12).

6. The pyrotechnical actuator unit according to claim 2, wherein the pressure chamber (16) is the remaining portion of the receiving space (24) that is not occupied by the pyrotechnical igniter (12).

7. The pyrotechnical actuator unit according to claim 5, wherein the receiving space (24) is bordered by the first plastic part (18) and by the second plastic part (20).

8. The pyrotechnical actuator unit according to claim 1, wherein the first plastic part (18) is injection-molded onto the igniter (12).

9. The pyrotechnical actuator unit according to claim 1, wherein the first plastic part (18) is a prefabricated injection-molded part and the second plastic part (20) is injection-molded onto the first plastic part (18).

10. The pyrotechnical actuator unit according to claim 1, wherein the two plastic parts (18, 20) are welded to each other.

11. The pyrotechnical actuator unit according to claim 1, wherein the first plastic part (18) has a first end (34) permanently connected with the second plastic part (20) and a second end (36) opposite the first end (34), and has a detent portion (38) in the area of the second end (36) to attach the actuator unit (10).

12. The pyrotechnical actuator unit according to claim 11, wherein the first plastic part (18) includes an outer, lateral guide portion (52) which is closer to the second end (36) of the first plastic part (18) than the detent portion (38).

13. The pyrotechnical actuator unit according to claim 1, wherein the first plastic part (18) has a first end (34) permanently connected with the second plastic part (20) and a second end (36) opposite the first end (34), and has an anti-rotation means (54) in the area of the second end (36).

14. A gas bag module for a vehicle safety system, comprising a gas bag (46), a gas generator, a module housing, and a pyrotechnical actuator unit (10) according to claim 1, wherein a traction means (32) is provided which is fixed in place by the actuator unit (10) before an activation of the pyrotechnical igniter (12) and is released after an activation of the pyrotechnical igniter (12).

15. The gas bag module according to claim 14, wherein one end of the traction means (32) engages a predefined breaking point (30) of the outer housing (14) of the pyrotechnical actuator unit (10).

16. The gas bag module according to claim 14, wherein one end of the traction means (32) engages a portion (47) of the outer housing (14) of the pyrotechnical actuator unit (10) which after the activation of the pyrotechnical igniter (12) is separated from an attachment section (49) of the pyrotechnical actuator unit (10).

17. A method of manufacturing a pyrotechnical actuator unit (10) comprising a pyrotechnical igniter (12) and an outer housing (14) accommodating the pyrotechnical igniter (12), the outer housing (14) being made up of a first housing part (48) and a second housing part (50), wherein the following steps:

(a) the first housing part (48) is produced to have a recess for the pyrotechnical igniter (12);

(b) the pyrotechnical igniter (12) is inserted into the recess;

(c) the second housing part (50) is injection-molded onto the pyrotechnical igniter (12) and onto a first end (34) of the first housing part (48), so that a receiving space (24) for the pyrotechnical igniter (12) is essentially closed.

18. The method according to claim 17, wherein the first housing part (48) is produced as an injection-molded part in step (a).

19. The method according to claim 17, wherein in step (b) a press fit develops between the pyrotechnical igniter (12) and a wall (41) of the first housing part (48).

20. The method according to claim 17, wherein in step (b) the pyrotechnical igniter (12) is not fully inserted into the recess, so that the igniter (12) and the first housing part (48) form a pressure chamber (16).

21. The method according to claim 17, wherein during the fabrication of the first housing part (48) a stop for the pyrotechnical igniter (12) is formed in the recess.

22. The method according to claim 17, wherein in step (c) an interlocking connection develops between the pyrotechnical igniter (12) and the second housing part (50).

23. The method according to claim 17, wherein in step (a) the first end (34) of the first housing part (48) is fabricated so as to be profiled such that after the second housing part (50) is joined by injection-molding and is cured, the two housing parts (48, 50) form a non-detachable interlocking connection.