Camshaft lobe and method of making same
View Patent ↗An automotive engine component and method of producing the same. The method uses dynamic magnetic compaction to form components, such as camshaft lobes, with non-axisymmetric and related irregular shapes. A die is used that has an interior profile that is substantially similar to the non-axisymmetric exterior of the component to be formed such that first and second materials can be placed into the die prior to compaction. The first material is in powder form and can be placed in the die to make up a first portion of the component being formed, while a second material can be placed in the die to make up a second portion of the component. The second material, which may possess different tribological properties from those of the first material, can be arranged in the die so that upon formation, at least a portion of the component's non-axisymmetric exterior profile is shaped by or includes the second material.
1. A method of fabricating an automotive engine component using dynamic magnetic compaction such that, upon formation, said component defines an exterior profile having axisymmetric and non-axisymmetric portions, said method comprising:
providing a die having (i) a first part that defines a portion of an interior profile substantially similar to said axisymmetric exterior profile portion of said component; and (ii) a second part that defines a portion of an interior profile substantially similar to said non-axisymmetric exterior profile portion of said component;
placing, within said first part of said die, a first material in powder form such that, when subjected to dynamic magnetic compaction, said first material defines at least a portion of said component corresponding to said axisymmetric exterior profile portion;
placing, within said second part of said die, a second material such that, when subjected to dynamic magnetic compaction, said second material defines at least a portion of said component corresponding to said non-axisymmetric exterior profile portion; and
forming said component from said first material and said second material using dynamic magnetic compaction;
wherein said formed component is a substantially unitary structure defining an exterior profile having axisymmetric and non-axisymmetric portions.
2. The method of claim 1 , wherein said component comprises a camshaft lobe.
3. The method of claim 1 , wherein said second material comprises a powder.
4. The method of claim 3 , wherein said powder of said second material comprises different tribological properties from said powder of said first material.
5. The method of claim 4 , wherein said second material has higher wear properties relative to said first material.
6. The method of claim 3 , wherein at least one of said first and second materials are selected from the group consisting of metal powders, ceramic powders and a combination of both.
7. The method of claim 1 , wherein said second material comprises at least one substantially rigid insert.
8. The method of claim 7 , wherein said at least one substantially rigid insert defines a profile such that, when subjected to said dynamic magnetic compaction along with said first material, defines at least a majority of said non-axisymmetric exterior profile.
9. The method of claim 8 , wherein said at least one substantially rigid insert comprises a non-reusable insert that remains with said component upon completion of said dynamic magnetic compaction.
10. The method of claim 7 , wherein during said forming, said at least one substantially rigid insert cooperates with at least one reusable insert that does not remain with said component such that an outer shape of said component is defined by said cooperation.
11. The method of claim 10 , wherein said at least one reusable comprises a plurality of segmented inserts that when placed within a die cooperate therewith to compact said first and second materials in response to said dynamic magnetic compaction.
12. A method of fabricating a camshaft lobe, said method comprising:
providing a die having (i) a first part that defines a portion of an interior profile substantially similar to an axisymmetric exterior surface portion of said lobe; and (ii) a second part that defines a portion of an interior profile substantially similar to a non-axisymmetric exterior surface portion of said lobe;
placing a first material within said first part of said die such that said first material, when subjected to dynamic magnetic compaction, defines at least a portion of said axisymmetric exterior surface portion of said lobe;
placing a second material within said second part of said die such that said second material, when subjected to dynamic magnetic compaction, defines at least a portion of said non-axisymmetric exterior surface portion of said lobe; and
forming said lobe from said first and second material using dynamic magnetic compaction;
wherein said formed lobe is a substantially unitary structure with an exterior surface having axisymmetric and non-axisymmetric portions.
13. The method of claim 12 , wherein said second material occupies a majority of said exterior surface of said lobe that corresponds to the lobe eccentricity.
14. The method of claim 12 , wherein at least one of said first and second materials comprises a powder.
15. The method of claim 14 , wherein said second material is of a different composition than said first material.
16. The method of claim 14 , wherein said second material comprises at least one substantially rigid insert.
17. The method of claim 16 , wherein said interior profile of said die is defined by a plurality of reusable inserts that cooperate with said at least one substantially rigid insert to press said second material thereof into said first material such that said lobe is formed as a substantially unitary structure.