Impact energy absorber with integrated engine exhaust noise muffler
Multifunction noise suppression and crash structures are disclosed. In one aspect of the disclosure, the multifunction structure includes a body, inlet and outlet pipes, and a plurality of walls within the body that bound resonator cells and that are configured to suppress exhaust noise passing through the resonator cells from the inlet to the outlet pipes. The structure may be positioned between crash rails at the rear of the vehicle and between the engine and bumper. The walls may be generally aligned with, or near, the predicted impact direction and they may crumple in a controlled manner during an impact. In various embodiments the structure is 3D printed to enable construction of a wide diversity of geometric topologies and to minimize mass.
1. A multifunction apparatus for a vehicle, comprising:
a muffler including a body having a plurality of walls that bound an array of resonator cells, the resonator cells arranged between inlet and outlet pipes to suppress exhaust noise;
wherein the walls are configured to controllably deform during an impact event,
wherein the walls include a posterior wall located at the bottom of the muffler, and the resonator cells are concentrated more densely the further their distance from the posterior wall,
wherein a length of at least one of the walls is aligned within an angle of 0° to 45° (degrees) from a direction parallel to a predicted direction of the impact event,
wherein the body comprises lateral sides with a longitudinal axis between the lateral sides, and
wherein an outlet pipe opening is on an upper portion of the muffler and between the lateral sides.
2. The apparatus of claim 1 , wherein the muffler comprises Inconel or titanium.
3. The apparatus of claim 1 , wherein the muffler comprises a material configured to controllably deform at a temperature of at least 800 degrees Celsius.
4. The apparatus of claim 1 , wherein the muffler is 3D printed.
5. The apparatus of claim 4 , wherein the muffler comprises a plurality of powder holes to enable removal of loose powder from within hollow portions of the body after the muffler is 3D printed.
6. The apparatus of claim 4 , further comprising a co-printed radiation shield surrounding an outer surface of the body and separated from the outer surface by an air gap.
7. The apparatus of claim 6 , wherein the radiation shield comprises walls shaped to conform to the body and configured to reduce an outflow of thermal radiation due to exhaust gasses in the muffler.
8. The apparatus of claim 7 , wherein the radiation shield is double-walled.
9. The apparatus of claim 1 , being configured to be positioned in a rear impact path of the vehicle.
10. The apparatus of claim 1 , wherein a lateral axis of the body is configured to be oriented between two crash rails and adjacent a rear vehicle bumper.
11. The apparatus of claim 10 , wherein a longitudinal axis of the body is further configured to be positioned between the engine and the rear vehicle bumper.
12. The apparatus of claim 1 , further comprising a suspension structure coupled to the body and configured to suspend the muffler between two crash rails near a rear bumper of the vehicle.
13. The apparatus of claim 12 , wherein the suspension structure is further configured to isolate the muffler from a chassis of the vehicle.
14. The apparatus of claim 1 , wherein at least some of the walls are configured to align with a directional axis of a rear impact event to enable the controlled deformation to increase energy absorption.
15. The apparatus of claim 1 , wherein regions of the body having non-perpendicular directional components to a direction of the impact event are configured to controllably deform during the impact event.
16. The apparatus of claim 15 , wherein the regions of the body include the posterior wall and side vertical walls.
17. The apparatus of claim 1 , wherein portions of at least one of the inlet pipe or the outlet pipe are configured to absorb energy by deforming during the impact event.
18. The apparatus of claim 1 , wherein the walls and the resonator cells are oriented and sized to achieve precise (i) energy absorption during the impact event and (ii) vehicle noise suppression.
19. The apparatus of claim 1 , further comprising:
a suspension rod; and
a suspension base separate from a chassis of the vehicle.
20. A multifunction noise suppression and energy absorption structure for a vehicle, comprising:
a muffler including a body, an inlet pipe, an outlet pipe, a posterior wall, and a plurality of internal walls within the body that bound an array of resonator cells;
wherein the internal walls are configured to absorb energy by deforming during an impact,
wherein the resonator cells are concentrated more densely the further their distance from the posterior wall,
wherein a length of at least one of the walls is aligned within an angle of 0° to 45° (degrees) from a direction parallel to a predicted direction of the impact event,
wherein the body comprises lateral sides with a longitudinal axis between the lateral sides, and
wherein an outlet pipe opening is on an upper portion of the muffler and between the lateral sides.
21. The structure of claim 20 , wherein the resonator cells are positioned between the inlet and outlet pipes to enable exhaust gasses to flow therebetween.
22. The structure of claim 20 , wherein the body is configured to be longitudinally positioned between crash rails of the vehicle to reduce energy absorbed by the crash rails during the impact.
23. The structure of claim 20 , wherein the body comprises a plurality of outer walls that are arranged to define external surfaces.
24. The structure of claim 23 , wherein one or more of the outer walls are configured to controllably deform during the impact.
25. The structure of claim 23 , wherein at least portions of the inlet and outlet pipes are configured to controllably deform during the impact.
26. The structure of claim 23 , further comprising a suspension structure coupled to the body and configured to allow suspension of the muffler between the rear bumper and the engine in a plane of a rear impact,
wherein the engine is located between a passenger cabin of the vehicle and the rear bumper.
27. The structure of claim 20 , wherein the muffler comprises a material configured to absorb energy during an impact while being at a temperature of at least 1000° (degrees) Celsius.
28. The structure of claim 20 , wherein the muffler is 3D printed.
29. The structure of claim 28 , wherein the muffler comprises a plurality of powder holes configured to enable removal of loose powder after the muffler is 3D printed.
30. The structure of claim 28 , further comprising a radiation shield co-printed over an outer surface of the body to form an air gap between the radiation shield and an outer surface of the body.
31. The structure of claim 20 , wherein at least some of the internal walls are configured to be aligned with a statistically predicted direction of the impact.
32. A dual function muffler, comprising:
a housing;
an inlet pipe;
an outlet pipe;
a posterior surface; and
a plurality of internal walls defining resonator cells, the internal walls being configured to deform during an impact event,
wherein the resonator cells are concentrated more densely the further their distance from the posterior surface,
wherein a length of at least one of the walls is aligned within an angle of 0° to 45° (degrees) from a direction parallel to a predicted direction of the impact event,
wherein the body comprises lateral sides with a longitudinal axis between the lateral sides, and
wherein an outlet pipe opening is on an upper portion of the muffler and between the lateral sides.
33. The muffler of claim 32 , wherein a lateral axis of the housing is configured to be positioned between rear crash rails to enable the muffler to reduce energy absorbed by the crash rails and to protect a vehicle occupant cabin during an impact event.
34. The muffler of claim 32 , wherein:
the internal walls are disposed in a horizontal direction of the housing and along a vertical direction of the housing to form the at least a portion of the resonator cells; and
wherein the resonator cells are concentrated more densely the further their distance from the posterior surface further comprises:
the horizontally-arranged internal walls are progressively spaced closer together when moving from the posterior surface of the housing toward an upper surface of the housing such that a denser concentration of walls, and smaller resonator cells, are present near the upper surface.
35. The muffler of claim 34 , wherein the upper surface of the housing is configured to be aligned more closely with a direction of the impact event than is the posterior surface.
36. The muffler of claim 34 , wherein one or more of the inlet pipe, the outlet pipe, and the housing are configured to controllably deform during the impact event.