U.S. patent application number 10/668039 was filed with the patent office on 2004-07-15 for method of making automotive parts having spline.
Invention is credited to Ambuhl, Erhard, Knoerr, Markus.
Application Number | 20040134252 10/668039 |
Document ID | / |
Family ID | 32030922 |
Filed Date | 2004-07-15 |
United States Patent
Application |
20040134252 |
Kind Code |
A1 |
Knoerr, Markus ; et
al. |
July 15, 2004 |
Method of making automotive parts having spline
Abstract
The present invention is directed to a method of making an
automotive part having a spline. Preferably, the automotive part is
a high strength automotive part having a relatively high carbon
content. The method includes pressing a spline tool having one or
more spline grooves into a bore defined by the automotive part so
that one or more splines are formed through the displacement of
material on the interior of the bore.
Inventors: |
Knoerr, Markus; (Bloomfield
Hills, MI) ; Ambuhl, Erhard; (Troy, MI) |
Correspondence
Address: |
MCDONALD HOPKINS CO., LPA
2100 BANK ONE CENTER
600 SUPERIOR AVENUE, E.
CLEVELAND
OH
44114-2653
US
|
Family ID: |
32030922 |
Appl. No.: |
10/668039 |
Filed: |
September 22, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60412654 |
Sep 20, 2002 |
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Current U.S.
Class: |
72/370.21 |
Current CPC
Class: |
B21D 53/88 20130101;
B21J 5/12 20130101; B21K 1/06 20130101 |
Class at
Publication: |
072/370.21 |
International
Class: |
B21D 017/00 |
Claims
Having thus described the invention, it is claimed:
1. A method of manufacturing an automotive part having a spline
comprising: forging an automotive part, said automotive part
including a bore; pressing a tool having at least one
spline-generating groove into said bore to form an automotive part
having a spline.
2. A method according to claim 1, wherein the part is formed from a
high strength carbon steel alloy.
3. A method according to claim 2, wherein the high strength carbon
steel alloy comprises at least 0.5% carbon.
4. A method according to claim 1, wherein the tool has an axial
length and two spline-generating grooves, said grooves commencing
at a terminal end of the tool and running along a portion of the
axial length of the tool that is less than the entire axial length
of the tool.
Description
PRIOR APPLICATIONS
[0001] This application claims priority to provisional application
serial No. 60/412,654, filed Sep. 20, 2002.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of automotive
parts. Particularly, the present invention is directed to a method
of making automotive parts having an interior spline through the
use of a metal forming process.
BACKGROUND OF THE INVENTION
[0003] In the automotive field, parts having splines are
particularly useful in creating interlocking articles or other
useful features in automotive parts. Previously, automotive parts
having one or more splines needed to be manufactured in a series of
main steps--most typically, forging, turning, pressing, refining
and broaching. In the forging step, a rod member is cut, heated,
shaped and trimmed to prepare a basic form of the spline part. In
the final broaching step, splines are then cut into the interior of
the part through the use of a spline broach. For example, U.S. Pat.
No. 2,726,435 discloses a reciprocating broach, used to make
particularized shapes on the interior of a bore, wherein the broach
possesses multiple axially aligned cutting teeth. This spline
broach, along with many others known in the art, is problematic for
automotive parts requiring a durable, high-strength spline because
splines formed by such broach are often defective at a rate that is
unacceptable to the automotive industry. More generally, spline
broaches are relatively unsuitable for small-sized splines. Lastly,
the cutting action of the broach itself possess substantial hazards
to the safety of those making the splines as well as to the quality
of the part being broached (for example, in the event that the
cutting broach fails or the point of contact for the reciprocating
action is inconsistent during the process).
[0004] Thus, it would be advantageous to form high-strength splines
in automotive parts in a manner that displaces, rather than cuts,
the metal--thereby resulting in superior quality splines in
comparison to previously known spline-cutting methods.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a method of
manufacturing an automotive part including a spline. The method
includes forging an automotive part. Preferably, the automotive
part includes a bore. The method further includes machining the
part and the bore. The method further includes pressing a spline
tool into the machined bore. The spline tool includes one or more
spline grooves. Preferably, the width or diameter of the tool is
equal to or greater than the width or diameter of the bore. The
pressing of the tool into the bore displaces the metal along an
interior axis of the bore, thereby creating one or more splines
(depending upon the shape of the tool). Preferably, the automotive
part is formed from a high strength metal, such as a steel alloy
with relatively high carbon content, preferably at least
0.5-1.0%.
[0006] Still other advantages and benefits of the invention will
become apparent to those skilled in the art upon a reading and
understanding of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention may take physical form in certain parts and
arrangements of parts, a preferred embodiment and method of which
will be described in detail in this specification and illustrated
in the accompanying drawings that form a part hereof, and
wherein:
[0008] FIG. 1 shows a cross-section of an automotive part 10 and a
spline tool 14 where the tool 14 is being pushed in to the bore 12
of the part 10.
[0009] FIG. 2 shows a perspective view of a preferred embodiment
wheel spindle 20.
[0010] FIG. 3 shows a perspective view of a terminal end of a
spline tool 14 having two spline grooves 18.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] The present invention is directed to a method for
manufacturing an automotive part having a spline. The method
includes forging an automotive part, where the automotive part
defines a bore. The method further includes machining the
automotive part and bore to a desired shape. The method also
includes pressing a tool including at least one spline groove into
the bore with sufficient force so that the tool forms a spline on
the inner portion of the part in the bore.
[0012] FIG. 1 shows an automotive part 10 defining a bore 12. A
spline tool 14 is pushed towards the automotive part 10. The bottom
16 of the spline tool 14 that first contacts the automotive part 10
has a diameter equal to or greater than the width or diameter of
the bore. Thus, the bottom 16 of the spline tool 14 contacts the
inner edge of the automotive part 10 that defines the bore 12.
[0013] The spline tool 14 includes one or more spline grooves 18.
In the spline tool shown in FIG. 1, the spline tool 14 includes two
spline grooves 18. The spline grooves 18 are generally recessed so
that when the tool 14 machines the bore 12 of the part 10, a spline
is formed on the inner portion of the part 10 defining the
bore.
[0014] In operation, when the spline tool 14 is pressed into the
bore 12 of the automotive part 10, the tool 14 forms the metal of
the part 10 in such a manner that carves away or shaves out a
portion of the material forming the inner portion of automotive
part 10 and defining the bore 12. Notably, the metal forming
process accomplished by the tool 14 occurs in a single downward
movement relative to the part 10, thereby eliminating any need to
have the tool 14 reciprocate during the metal forming process.
Splines are formed on the inner portion of the part 10 defining the
bore 12 in a pattern which mirrors the spline grooves 18 of tool
14.
[0015] The spline grooves 18 are preferably formed at a terminal
end of the tool 14. The number of grooves may vary according to the
type of automotive part 10 being manufactured. However, as best
illustrated in FIGS. 1 and 3, it is anticipated that a tool 14
having two grooves 18 which commence at a terminal end of the tool
14 and run parallel to one another along only an axial portion of
the tool 14 (rather than the entire axial length of the tool 14)
will be a preferred embodiment.
[0016] Any automotive part that requires the machining of a spline
is contemplated in the present invention. Preferably, the
automotive part formed with the present method is a wheel spindle,
although of course other automotive parts are contemplated. FIG. 2
shows the preferred wheel spindle 20 that defines a bore 22 along
its longitudinal axis. Preferably, the automotive part formed with
the present method defines an aperture or bore. The spline is
formed on the automotive part in the bore. The bore is generally
cylindrical although other shapes are contemplated.
[0017] The automotive part is formed from a steel alloy material.
Preferably, the material forming the part includes a relatively
high amount of carbon in the range of from about 0.5% to about 1.0%
by weight. Generally, carbon in amount greater than 2% by weight
should be avoided because such a high amount of carbon forms an
iron exhibiting undesirably high brittleness properties.
[0018] The spline tool is generally cylindrically shaped, although
other shapes are contemplated. Preferably, the shape of the spline
tool will be the same as the shape of the bore. The tool includes
one or more spline grooves. FIG. 3 shows the bottom of a spline
tool 14 having two spline grooves 18; however, the spline grooves
can be of any shape depending on the desired shape of the final
spline formed in the automotive part. The inner width or diameter
of the tool 14 is preferably greater than the width or diameter of
the bore, whereas the outer diameter of the tool 14 must allow for
appropriate contact between the tool 14 and the part 10 during the
pressing, or metal forming, part of the process. The inner diameter
is defined by the narrowest width of the tool (for example, as
shown in FIG. 3, from one edge of the spline groove 18 to the
opposite edge along the bottom end 16), while the outer diameter
represents the thickest width of the tool 14.
[0019] The invention has been described with reference to the
preferred embodiment. Obviously, modifications and alterations will
occur to others upon a reading and understanding of this
specification. It is intended to include all such modifications and
alterations insofar as they come within the scope of the appended
claims or the equivalents thereof.
* * * * *