U.S. patent application number 11/063915 was filed with the patent office on 2006-08-24 for manufacturing a rocker lever using cold forming and welding.
This patent application is currently assigned to Gen Tek Technologies Marketing, Inc.. Invention is credited to John E. Brune, Scott P. Smith.
Application Number | 20060185636 11/063915 |
Document ID | / |
Family ID | 36911309 |
Filed Date | 2006-08-24 |
United States Patent
Application |
20060185636 |
Kind Code |
A1 |
Brune; John E. ; et
al. |
August 24, 2006 |
Manufacturing a rocker lever using cold forming and welding
Abstract
A method and system for forming a rocker assembly includes cold
forming a metal blank to produce a portion of the rocker assembly.
This portion has a tubular portion that rotatably engages a shaft
and an arm that couples with a pushrod. This portion is welded to a
valve lever to form the rocker assembly.
Inventors: |
Brune; John E.;
(Stockbridge, MI) ; Smith; Scott P.; (Temperance,
MI) |
Correspondence
Address: |
GENERAL CHEMICAL PERFORMANCE PRODUCTS LLC.
90 EAST HALSEY ROAD
PARSIPPANY
NJ
07054
US
|
Assignee: |
Gen Tek Technologies Marketing,
Inc.
Parsipanny
NJ
07054
|
Family ID: |
36911309 |
Appl. No.: |
11/063915 |
Filed: |
February 23, 2005 |
Current U.S.
Class: |
123/90.39 |
Current CPC
Class: |
F01L 1/181 20130101;
F01L 2305/00 20200501; F01L 2303/00 20200501; F01L 2001/2427
20130101; F01L 1/146 20130101; Y10T 29/49231 20150115 |
Class at
Publication: |
123/090.39 |
International
Class: |
F01L 1/18 20060101
F01L001/18 |
Claims
1. A rocker assembly for an engine comprising: a tubular member
having a first axial end, a second axial end, and an integrally
formed arm adjacent said first axial end; and a valve lever coupled
to said tubular member adjacent said second axial end and opposite
of said arm.
2. The assembly of claim 1 further comprising: a cup formed within
said arm, said cup adapted to selectively couple with a push
rod.
3. The assembly of claim 1 further comprising: a valve contacting
surface formed on said valve lever.
4. The assembly of claim 1 wherein a side of said valve lever
contacts an axial end of said tubular member.
5. The assembly of claim 1 wherein said valve lever is coupled to
said tubular member by welding.
6. The assembly of claim 1 wherein said valve lever is coupled to
said tubular member by laser welding.
7. The assembly of claim 1 wherein said valve lever is coupled to
said tubular member by electron beam welding.
8. The assembly of claim 1 wherein said valve lever is coupled to
said tubular member by pulsed plasma arc welding.
9. A method of manufacturing a cam-engaged rocker comprising:
obtaining a metal blank, said metal blank defined, at least in
part, by a first surface, an opposing second surface, a peripheral
surface intersecting both said first surface and said second
surface, and a projection, wherein said metal blank contains a
predetermined amount of a metal; and forming at least a portion of
said metal blank by exerting a force on said metal blank adjacent
said first surface, wherein a tubular portion is formed by the flow
of a portion of said metal.
10. The method of claim 9, wherein forming said metal blank
includes cold forming a central portion of said metal blank.
11. The method of claim 9, further comprising forming a cup in said
projection.
12. The method of claim 9, further comprising radially aligning a
valve lever to said tubular portion.
13. The method of claim 9, further comprising welding a valve lever
to said tubular portion.
14. The method of claim 13, wherein said welding comprises laser
welding.
15. A method of manufacturing a cam-engaged rocker comprising:
obtaining an annular metal blank, said annular metal blank defined,
at least in part, by an outer cylindrical surface, an inner
cylindrical surface a valve end, and a cup end, wherein said
annular metal blank contains a predetermined amount of a metal; and
forming a projection on said annular metal blank by exerting a
force on at least a portion of said annular metal blank adjacent
said cup end, wherein a projection is formed by the flow of a
portion of said metal, the projection extending from a tubular
portion.
16. The method of claim 15, further comprising: positioning said
annular metal blank adjacent a die, wherein said die includes a
cavity, wherein forming the annular metal blank includes exerting a
force on said annular metal blank in a predetermined direction
thereby causing a flow of the metal into said cavity.
17. The method of claim 15, further comprising forming a cup in
said projection.
18. The method of claim 15, further comprising welding a valve
lever to said tubular portion.
19. The method of claim 18, wherein said welding comprises laser
welding
Description
TECHNICAL FIELD
[0001] The present invention relates to rocker arms for valve-type
engines. More specifically, the invention relates to cold forming a
shaft portion of a rocker assembly.
BACKGROUND OF THE INVENTION
[0002] In automotive and other applications, an engine typically
utilizes a plurality of rocker arms for alternately actuating
intake and exhaust valves. As an engine cam shaft rotates, a push
rod is selectively actuated by cams connected to the cam shaft. The
push rods, in turn, direct an upward force on one end of a rocker
arm to cause the rocker arm to pivot about a mounting shaft. As the
rocker arm pivots, its opposite end generates a downward force to
selectively open an intake or exhaust engine valve.
[0003] Typically, rocker arms are integral, one-piece parts having
a generally U-shaped cross-section including a pair of opposing
side walls separated by a bottom wall and a pair of end walls
disposed between the side walls. Rocker arms are conventionally
cast an integral piece. This piece is then machined to its final
dimensions. This process may involve multiple forming steps or
processing stages and, therefore, require additional expense to
produce a finished rocker assembly.
[0004] Rocker arms can be manufactured in a variety of ways, such
as by casting metals, blanking and forming, ceramic molding, and
other methods. Stamping a metal blank to form a cam-engaged rocker
arm is one known method of manufacturing. The rocker arms are
typically formed using a stamping, folding or coining process.
During the coining process, an upper die and a lower die punch an
area of the metal blank to plastically deform the metal blank.
While previous methods of producing a rocker arm have been employed
with some success, the manufacture of rocker arms has been an area
of constant innovation. Specifically, methods to reduce the time
and complexity involved in forming a rocker arm, thereby reducing
the associated costs are desirable.
SUMMARY OF THE INVENTION
[0005] The present invention overcomes the deficiencies of the
prior art by preparing a blank of generally uniform thickness for
forming a tubular member of a rocker assembly. In one embodiment, a
rocker assembly for an engine is provided. The rocker assembly
includes a tubular member having a first axial end, a second axial
end, and an integrally formed arm adjacent said first axial end
with a valve lever coupled to the tubular member adjacent the
second axial end.
[0006] In another embodiment, a method of manufacturing a
cam-engaged rocker is provided. The method includes obtaining a
metal blank that is defined, at least in part, by a first surface,
an opposing second surface, a peripheral surface intersecting both
the first surface and the second surface, and a projection. The
metal blank contains a predetermined amount of a metal. The method
further includes forming at least a portion of the metal blank by
exerting a force on the metal blank adjacent the first surface,
where a tubular portion is formed by the flow of a portion of said
metal.
[0007] In yet another embodiment, a method of manufacturing a
cam-engaged rocker that includes obtaining an annular metal blank
that is defined, at least in part, by an outer cylindrical surface,
an inner cylindrical surface, a valve end and a cup end. The
annular metal blank contains a predetermined amount of a metal. The
method further includes forming at least a portion of the annular
metal blank by exerting a force on the annular metal blank adjacent
the cup end, where a projection is formed by the flow of a portion
of said metal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of a valve train assembly
illustrating an embodiment of the rocker arm of the present
invention.
[0009] FIG. 2 is a perspective view of the rocker arm of FIG.
1.
[0010] FIG. 3 is an exploded side view of the rocker arm of FIG.
1.
[0011] FIG. 4 is a perspective of an embodiment of a metal blank
before forming a shaft portion of the rocker arm of FIG. 1.
[0012] FIG. 5 is a perspective view of an embodiment of an
intermediate article of manufacture in accordance with the present
invention.
[0013] FIG. 6 is a perspective view of the tubular portion of the
rocker arm of FIG. 3.
[0014] FIG. 7 is a perspective view of an embodiment of an annular
blank in accordance with the present invention.
[0015] FIG. 8 is a flow chart illustrating an embodiment of a
method of producing a rocker assembly in accordance with the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] Referring to FIG. 1, a valve train assembly 20 is
illustrated. Valve train assembly 20 includes a plurality of valves
22, cam lobes 24, lifters, or tappets, 26, pushrods 28, rocker
assemblies 30, and rocker shafts 32. As illustrated, valve train
assembly 20 operates as a camshaft (not shown) is rotated, causing
cam lobes 24 to rotate and push lifters 26. Lifters 26 push
pushrods 28 causing pushrods 28 to rotate the rocker assemblies 30
about the rocker shafts 32.
[0017] With reference to FIGS. 2 and 3, the rocker assembly 30 made
in accordance with the present invention is illustrated in greater
detail. Rocker assembly 30 includes a tubular member 34 and a valve
lever 36. Tubular member 34 includes a tubular portion 38 defining
a first axial end 40, a second axial end 42, and an arm 44
protruding from the first axial end 40. In one embodiment, arm 44
is integrally formed with first axial end 40. Tubular member 34
further includes an inner surface 46 and an outer surface 48. Arm
44 includes a contoured outer surface 50, with a cup 52 formed
therein.
[0018] Valve lever 36 includes a central body portion 60 having a
valve contacting portion 62 formed thereon and a circular inner
surface 66 defining an aperture 68. Valve lever 36 is further
defined by a first side 70, a second side 72, and an outer surface
74 intersecting therebetween. Valve contacting portion 62 includes
an outer protuberate surface 80 with a valve contacting surface 82
formed thereon. As illustrated, valve contacting portion 62 has a
greater thickness, measured parallel to the axis of aperture 68,
than central body portion 60. Circular inner surface 66 intersects
both the first side 70 and the second side 72.
[0019] As shown in FIGS. 2 and 3, the first side 70 of valve lever
36 abuts the second axial end 42 of the tubular member 34. Circular
inner surface 66 of aperture 68 and inner surface 46 are aligned
such that rocker shaft 32 (FIG. 1) may be positioned through both
circular inner surface 66 and inner surface 46 during operation.
While valve lever 36 and tubular member 34 are illustrated as
coupled wherein valve lever 36 abuts tubular member 34, valve lever
36 may alternatively be positioned about the outer surface 48 of
tubular member 34, such that circular inner surface 66 encircles a
portion of outer surface 48.
[0020] Referring now to FIG. 4, a metal blank 90 is shown according
to an embodiment of the present invention. As illustrated, metal
blank 90 has a first surface 92, a second surface 94, and a
peripheral surface 96 intersecting both the first surface 92 and
the second surface 94. Metal blank 90 includes a central body
portion 100 and an arm portion 102 extending therefrom.
[0021] FIG. 5 illustrates an embodiment of an intermediate article
of manufacture in the method of forming rocker assembly 30 as a
formed article 134. Formed article 134 is illustrated to include a
tubular portion 138 defining a first axial end 140, a second axial
end 142, and a projection 144 protruding from the first axial end
140. Formed article 134 further includes an inner surface 146 and
an outer surface 148. Projection 144 is illustrated to include a
contoured outer surface 150. Formed article 134 is preferably cold
formed, as discussed herein.
[0022] FIG. 6 illustrates the tubular member 34 of rocker assembly
30 in greater detail. FIG. 7 illustrates an embodiment of a tubular
blank 170 in accordance with the present invention. Tubular blank
170 includes a first end 172, a second end 174, an inner surface
176, and an outer surface 178. First end 172 is defined by an
extended annular surface 180 that intersects the inner surface 176
and the outer surface 178.
[0023] FIG. 8 illustrates a method of manufacturing the rocker
assembly 30. The method includes step 300, wherein a blank material
is obtained for producing the tubular member 34. In step 310, the
blank material is formed into a blank of a desired shape. In one
embodiment of step 310, the desired shape is the metal blank 90, as
illustrated in FIG. 4. In an alternative embodiment of step 310,
the desired shape is the tubular blank 170, as illustrated in FIG.
7. In step 320, the blank is formed into a formed article. In one
embodiment of step 320 the article formed is the formed article
134, as illustrated in FIG. 5. Preferably, step 320 involves cold
forming the blank, although other suitable forming means, such as
heated extrusion, may be used. In step 330, a cup 52 is formed. In
one embodiment of step 330, the article that is formed is the
tubular member 34, as illustrated in FIG. 6. Steps 320 and 330 may
be performed concurrently with a suitable forming process.
[0024] In step 340, a blank is obtained for forming a valve lever.
In step 350, the blank is formed into a valve lever. Step 350 may
involve multiple process operations wherein a first predetermined
shape is formed, such as by coining a metal sheet, and then the
predetermined shape is further processed to form the valve
contacting portion 62. In step 370, the valve lever is positioned
adjacent the tubular member in a desired radial alignment. This
desired radial alignment is determined by a predetermined radial
offset, or relative angle, between cup 52 and valve contacting
surface 82. As will be appreciated, differing rocker assemblies 30
can be produced by varying the predetermined radial offset. In step
380, the valve lever is fixedly secured to the tubular member to
produce a rocker assembly. In one embodiment, the valve lever is
welded to the tubular member. Acceptable welding processes include
laser welding, pulsed plasma arc welding, and electron beam
welding.
[0025] The forming processes discussed herein may include, but are
not limited to, cold forming a tubular portion, such as by using a
drawing die or mandrel, or forming a portion of a blank by
punching, or pressing, a portion of the blank into a cavity formed
within into a die (not shown). In this type of forming process, the
blank is positioned adjacent a die and at least a portion of the
blank is formed into a desired, or predetermined, shape as the
blank material is plastically deformed.
[0026] Additionally, the axial length of the tubular member 34, or
the positioning of cup 52 along the axial length of tubular member
34, may be varied, as desired, to vary the linear distance between
the cup 52 and the valve lever 36. As a result, the rocker assembly
30 may be adapted for a variety of valve configurations and desired
relative angles. In addition, the tubular member 34 and valve lever
36 may be used for both inlet and exhaust valve applications,
thereby reducing the total number of parts used in a cylinder valve
assembly. A reduced part count further reduces the cost of such an
assembly.
[0027] While the invention has been described with respect to
specific examples including preferred modes of carrying out the
invention, those skilled in the art will appreciate that there are
numerous variations and permutations of the above described systems
and techniques that fall within the spirit and scope of the
invention as set forth in the appended claims.
* * * * *