Tunable, healable vehicle impact devices

• US 20050104391A1
• Filed: 11/18/2003
• Published: 05/19/2005
• Est. Priority Date: 11/18/2003
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Kramarczyk, Mark A., Browne, Alan L., Johnson, Nancy L.
• Granted Patent: US 7,029,044 B2
• Time in Patent Office: Days
• US Class Current: 293/132
• CPC Class Codes: B60R 19/03 characterised by material, e.g. composite B60R19/18 takes precedence
• CPC Class Codes: B60R 19/26 comprising yieldable mounting means B60R19/38 takes precedence; springs, shock absorbers, or means for damping vibrations per se F16F
• CPC Class Codes: B60R 19/36 Combinations of yieldable mounting means of different types fluid shock absorbers with coaxial coil springs B60R19/32
• CPC Class Codes: B60R 19/40 in the direction of an obstacle before a collision , or extending during driving of the vehicle, i.e. to increase the energy absorption capacity of the bumper inflatable bumpers B60R19/20
• CPC Class Codes: F16F 2224/0258 Shape-memory metals, e.g. Ni-Ti alloys
• CPC Class Codes: F16F 7/125 Units with a telescopic-like action as one member moves into, or out of a second member F16F7/124, F16F7/127, F16F7/128 take precedence
• CPC Class Codes: F16F 7/128 characterised by the members, e.g. a flat strap, yielding through stretching, pulling apart

Abstract

An impact absorbing device for a vehicle uses a shape memory material that can be heated to repair deformation from a relatively low speed, low energy impact and its stroking force and energy absorption can be tuned by heating. The shape memory material is suitably used in a crash box having an inserted impact absorbing ram, the box being placed, for example, between a bumper and strong body member. The shape memory material is attached to the box and ram for absorbing energy as the ram is driven into the box. Heating means is provided to repair or tune the shape memory material.

Claims

1. A device for absorption of impact energy when fixed in use to a vehicle body component, said device comprising one or more deformable members of shape memory material aligned for deformation by an impact on said device.

2. The device recited in claim 1 in which said member or members are aligned between a vehicle bumper and a vehicle body rail.

3. The device recited in claim 1 comprising:

a crash box having an inlet end;

a ram having a first end partially inserted into the inlet end of the box and a second end, the ram being aligned when fixed in use to receive an impact on said vehicle body at the second end and to be driven by said impact further into said crash box; and

one or more of said deformable members, said deformable member(s) having two ends with one end being fixed to said box and the other end fixed to said ram for absorption of impact energy.

4. The device recited in claim 1 in which said deformable member is a shape memory metal alloy.

5. The device recited in claim 1 in which said deformable member is a shape memory metal alloy comprising titanium and nickel.

6. The device as recited in claim 3 in which said deformable member comprises a spring.

7. The device as recited in claim 3 in which said deformable member comprises a sheet.

8. The device as recited in claim 3 in which said deformable member comprises a roll of sheet material.

9. The device as recited in claim 3 in which said deformable member comprised a collapsible tube.

10. The device as recited in claim 3 in which said deformable member comprises a set of concentric tubes.

17. The device recited in claim 1 in which said deformable member is a shape memory polymer or a combination of a shape memory alloy and shape memory polymer.

11. A device for absorption of impact energy when fixed in use to a vehicle body component, said device comprising one or more deformable members of a shape memory metal alloy aligned for deformation by an impact on said device, said members being deformable from an initial shape under an impact of predetermined magnitude and thereafter restorable to their initial shape upon being heated to a predetermined temperature.

12. The device for absorption of impact energy as recited in claim 11 in which said one or more deformable members of a shape memory metal alloy are electrically conductive and restorable to their initial shape upon being heated by electrical resistance heating to a predetermined temperature.

13. The device for absorption of impact energy as recited in claim 11 in which said one or more deformable members comprise titanium and nickel.

14. A device for absorption of impact energy when fixed in use to a vehicle body component, said device comprising:

a crash box having an inlet end;

a ram having a first end partially inserted into the inlet end of the crash box and a second end, the ram being aligned when fixed in use to receive an impact on said vehicle body at the second end and to be driven by said impact further into said crash box;

one or more deformable members of shape memory material, said members being deformable from an initial shape under an impact of predetermined magnitude and thereafter restorable to their initial shape upon being heated to a predetermined temperature, said deformable member(s) having two ends with one end being fixed to said box and the other end fixed to said ram for absorption of impact energy; and

means for heating said one or more deformable members.

15. The device recited in claim 14 in which said deformable member is a shape memory metal alloy.

16. The device recited in claim 14 in which said deformable member is a shape memory metal alloy comprising titanium and nickel.

18. The device recited in claim 14 in which said deformable member is a shape memory polymer or a combination of a shape memory alloy and shape memory polymer.