J-groove for crack suppression

Patent metadata

Field	Value
Publication number	US-10753266-B2
Application number	US-201815981194-A
Country	US
Kind code	B2
Filing date	May 16, 2018
Priority date	May 16, 2018
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

An exhaust manifold for an internal combustion engine includes a first exhaust port, a second exhaust port, and a septum that separates the first exhaust port and the second exhaust port. The septum has a surface with a J-groove to relieve stresses by looping a tip of a crack initiated by the J-groove back into a stress field of the J-groove.

First claim

What is claimed is:

1. An exhaust manifold for an internal combustion engine, the exhaust manifold comprising:
a first exhaust port;
a second exhaust port; and
a septum that separates the first exhaust port and the second exhaust port, the septum having a surface with a J-groove, the J-groove having a linear portion that extends along the surface of the septum, the linear portion having a proximal end and a distal end, and a curved portion that extends from the distal end of the linear portion over the surface of the septum to a distal tip to relieve stresses by looping a tip of a crack initiated by the J-groove back into a stress field of the J-groove.

2. The exhaust manifold of claim 1 wherein the curvature of the curved portion prevents the crack from continuing out the J-groove.

3. The exhaust manifold of claim 1 wherein the length of J-groove determines the amount of stress relief provided by the J-groove.

4. The exhaust manifold of claim 1 wherein the relieved stresses provided by the J-groove prevents the initiation of cracks in other portions of the exhaust manifold.

5. The exhaust manifold of claim 1 wherein the J-groove relieves stresses by about 25%.

6. The exhaust manifold of claim 1 wherein a maximum stress at a distal tip of the J-groove is about 175 MPa.

7. The exhaust manifold of claim 1 wherein the J-groove has a V-shaped notch cross-sectional shape.

8. The exhaust manifold of claim 7 wherein the V-shaped notch is configured to initiate a crack at the bottom of the notch.

9. The exhaust manifold of claim 8 wherein the crack initiates at the proximal end of the linear portion, the crack propagating from the proximal end of the linear portion to the distal tip of the curved portion and terminating at the distal tip.

10. A mechanical component comprising:
a J-groove including:
a linear portion that extends along the surface of a septum, the linear portion having a proximal end and a distal end; and
a curved portion that extends from the distal end of the linear portion over the surface of the septum to a distal tip,
wherein the J-groove relieves stresses in the mechanical component
by looping a tip of a crack initiated by the J-groove back into a stress field of the J-groove.

11. The mechanical component of claim 10 wherein the curvature of the curved portion prevents the crack from continuing out the J-groove.

12. The mechanical component of claim 10 wherein the length of J-groove determines the amount of stress relief provided by the J-groove.

13. The mechanical component of claim 10 wherein the relieved stresses provided by the J-groove prevents the initiation of cracks in other portions of the mechanical component.

14. The mechanical component of claim 10 wherein the J-groove relieves stresses by about 25%.

15. The mechanical component of claim 10 wherein a maximum stress at the distal tip of the J-groove is about 175 MPa.

16. The mechanical component of claim 10 wherein the J-groove has a V-shaped notch cross-sectional shape.

17. The mechanical component of claim 16 wherein the V-shaped notch is configured to initiate a crack at the bottom of the notch.

18. The mechanical component of claim 17 wherein the crack initiates at the proximal end of the linear portion, the crack propagating from the proximal end of the linear portion to the distal tip of the curved portion and terminating at the distal tip.

19. An exhaust manifold for an internal combustion engine, the exhaust manifold comprising:
a first exhaust port;
a second exhaust port; and
a septum that separates the first exhaust port and the second exhaust port, the septum having a surface with a J-groove, the J-groove having a linear portion that extends along the surface of the septum, the linear portion having a proximal end and a distal end, and a curved portion that extends from the distal end of the linear portion over the surface of the septum to a distal tip to relieve stresses by looping a tip of a crack initiated by the J-groove back into a stress field of the J-groove,
wherein the J-groove has a V-shaped notch cross-sectional shape, the V-shaped notch being configured to initiate a crack at the bottom of the notch, and
wherein the crack initiates at the proximal end of the linear portion and propagates from the proximal end of the linear portion to the distal tip of the curved portion and terminates at the distal tip.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Karram Michael A
• Ouang Xin

Classifications

• F01N13/10 Primary

  of exhaust manifolds {(with cooling jacket F01N3/046)} · CPC title

• F01N13/1805 Primary

  Fixing exhaust manifolds, exhaust pipes or pipe sections to each other, to engine or to vehicle body (pipe joints in general F16L; fixing auxiliaries in motor vehicles in general B60K) · CPC title