METHODS FOR MANUFACTURING CONNECTING ROD ASSEMBLIES AND CRANKSHAFT ASSEMBLIES

• US 20200130060A1
• Filed: 10/30/2018
• Published: 04/30/2020
• Est. Priority Date: 10/30/2018
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Bobel, Andrew C., Brown, Tyson W., Poling, Whitney A.
• Granted Patent: US 11,117,191 B2
• Time in Patent Office: Days
• CPC Class Codes: B22F 10/20 Direct sintering or melting
• CPC Class Codes: B22F 10/36 of energy beam parameters
• CPC Class Codes: B22F 10/38 to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures
• CPC Class Codes: B22F 10/64 by thermal means control of energy beam parameters for post heating B22F10/364
• CPC Class Codes: B22F 2202/11 Use of irradiation
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 5/003 Articles made for being fractured or separated into parts
• CPC Class Codes: B22F 5/008 of engine cylinder parts or of piston parts other than piston rings of piston rings B22F5/02
• CPC Class Codes: B22F 5/10 of articles with cavities or holes, not otherwise provided for in the preceding subgroups
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: F16C 2204/20 Alloys based on aluminium
• CPC Class Codes: F16C 2204/42 Alloys based on titanium
• CPC Class Codes: F16C 2204/60 Ferrous alloys, e.g. steel alloys
• CPC Class Codes: F16C 2220/20 by sintering pulverised material, e.g. powder metallurgy in general B22F
• CPC Class Codes: F16C 2220/80 by separating parts, e.g. by severing, cracking
• CPC Class Codes: F16C 2240/60 Thickness, e.g. thickness of coatings
• CPC Class Codes: F16C 3/06 Crankshafts
• CPC Class Codes: F16C 7/023 for piston engines, pumps or the like
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A connecting rod comprises a shaft connecting a first end including a first bore with a second end including a second bore. Methods for forming and assembling a connecting rod and crankshaft assembly include fabricating the second end of the connecting rod via additive manufacturing such that the second end comprises a first and second weakened regions on opposing sides of the second bore, and breaking the second end of the connecting rod at the first and second weakened regions to form a connecting rod assembly comprising a second end base and a second end cap, wherein the base comprises a first fracture face and a second fracture face which each respectively correspond to a first fracture face and a second fracture face of the cap. The methods can further include mating the base and the cap such that a crankpin of a crankshaft is disposed within the second bore.

Claims

1. A method for manufacturing a connecting rod assembly, wherein a connecting rod comprises a shaft connecting a first end including a first bore with a second end including a second bore, the method comprising:

fabricating the second end of the connecting rod via additive manufacturing wherein a plurality of stacked metal layers are formed by selectively applying heat or energy to one or more metal precursors, and the additive manufacturing conditions are controlled such that the fabricated second end comprises a first weakened region and a second weakened region on opposing sides of the second bore; and

breaking the second end of the connecting rod at each of the first and second weakened regions to form a connecting rod assembly comprising a second end base and a second end cap, wherein the base comprises a first fracture face and a second fracture face which each respectively correspond to a first fracture face and a second fracture face of the cap.

2. The method of claim 1, wherein the base first fracture face and base second fracture face are matable with the cap first fracture face and the cap second fracture face, respectively.

3. The method of claim 1, wherein one or more of the base first fracture face, the base second fracture face, the cap first fracture face, and the cap second fracture face are non-planar.

4. The method of claim 1, wherein the first and second weakened regions are 180 degrees apart.

5. The method of claim 1, wherein the first and second weakened regions each comprise a higher porosity relative to the average porosity of the second end of the connecting rod.

6. The method of claim 1, wherein the second end of the connecting rod comprises a plurality of metal phases, and the first and second weakened regions comprise a higher concentration of one or more brittle metal phases relative to the average concentration of the one or more brittle metal phases throughout the second end of the connecting rod.

7. The method of claim 1, wherein the one or more metal precursors comprise aluminum, steel, and/or titanium alloys.

8. The method of claim 1, wherein a laser is used to selectively apply heat to the one or more metal precursors, and the first and/or second weakened regions are formed by manipulating the laser exposure to over-expose the weakened region.

9. The method of claim 1, wherein a laser is used to selectively apply heat to the one or more metal precursors, and the first and/or second weakened regions are formed by manipulating the laser exposure to under-expose the weakened region such that unmelted or unconsolidated metal precursor powder is present in the weakened region.

10. A method for forming and assembling a connecting rod and crankshaft assembly, wherein a connecting rod comprises a shaft connecting a first end including a first bore with a second end including a second bore, the method comprising:

fabricating the second end of the connecting rod via additive manufacturing wherein a plurality of stacked metal layers are formed by selectively applying heat or energy to one or more metal precursors, and the additive manufacturing conditions are controlled such that the fabricated second end comprises a first weakened region and a second weakened region on opposing sides of the second bore;

breaking the second end of the connecting rod at each of the first and second weakened regions to form a connecting rod assembly comprising a second end base and a second end cap, wherein the base comprises a first fracture face and a second fracture face which each respectively correspond to a first fracture face and a second fracture face of the cap; and

mating the second end base and the second end cap such that a crankpin of a crankshaft is disposed within the second bore.

11. The method of claim 10, wherein mating the second end base and the second end cap comprises mating the base first fracture face with the cap first fracture face and mating the base second fracture face with the cap second fracture face.

12. The method of claim 11, wherein mating further comprises mechanically locking the cap to the base with one or more bolts.

13. The method of claim 10, wherein one or more of the base first fracture face, the base second fracture face, the cap first fracture face, and the cap second fracture face are non-planar.

14. The method of claim 10, wherein the first and second weakened regions are 180 degrees apart.

15. The method of claim 10, wherein the first and second weakened regions each comprise a higher porosity relative to the average porosity of the second end of the connecting rod.

16. The method of claim 10, wherein the second end of the connecting rod comprises a plurality of metal phases, and the first and second weakened regions comprise a higher concentration of one or more brittle metal phases relative to the average concentration of the one or more brittle metal phases throughout the second end of the connecting rod.

17. The method of claim 10, wherein the one or more metal precursors comprise aluminum, steel, and/or titanium alloys.

18. The method of claim 10, wherein a laser is used to selectively apply heat to the one or more metal precursors, and the first and/or second weakened regions are formed by manipulating the laser exposure to over-expose the weakened region.

19. The method of claim 10, wherein a laser is used to selectively apply heat to the one or more metal precursors, and the first and/or second weakened regions are formed by manipulating the laser exposure to under-expose the weakened region such that unmelted or unconsolidated metal precursor powder is present in the weakened region.

20. A method for forming and assembling an automotive component assembly, wherein an automotive component comprises an end including a bore, the method comprising:

fabricating the automotive component end via additive manufacturing wherein a plurality of stacked metal layers are formed by selectively applying heat or energy to one or more metal precursors, and the additive manufacturing conditions are controlled such that the fabricated end comprises a first weakened region and a second weakened region on opposing sides of the bore;

breaking the end of the automotive component at each of the first and second weakened regions to form an automotive component assembly comprising an end base and an end cap, wherein the base comprises a first fracture face and a second fracture face which each respectively correspond to a first fracture face and a second fracture face of the cap; and

mating the end base and the end cap such that an automotive member is disposed within the bore.