Support tool for deep rolling crankshaft fillets

Deep rolling equipment for cold working fillet radii of annular undercuts on opposite sides of main bearing and crank pin journals of an engine crankshaft while being rotatably driven. The equipment has pairs of jaws movable between an open position for receiving the crankshaft journal and a closed position for rolling the fillets thereof. The upper jaw mounts fillet rolling tools for high load rolling engagement in the annular undercuts and a lower tool on the opposing lower jaw for support of the journal. The lower tool has a pair of support rollers with annular journal support portions which contact and support the journal while the fillet radii of the undercuts on either side of the journal are being rolled. These support rollers importantly have work stabilizing annular flanges outboard of the support portion with larger diameters that ride in the undercuts and limit lateral movement of the crankshaft with respect to the rolling and support tools so that the crankshaft is not abraded or otherwise damaged by side contact of the jaws and tools with portions of the crankshaft.

TECHNICAL FIELD 
The present invention relates to a lower support tool for deep rolling 
fillets of a crankshaft. More specifically, the invention relates to a new 
and improved apparatus for limiting relative lateral movement between the 
crankshaft and the fillet rolling is tools of a jaw assembly during 
rolling operation. 
BACKGROUND ART 
Deep rolling of crankshaft journal fillets for crankshaft strengthening 
purposes is well known in the art. The journals of a crankshaft for 
internal combustion engines are disposed between laterally spaced 
counterweights formed on the crankshaft. The journal fillets are located 
at the intersection of the journal and the adjacent counterweight and 
define concentrated annular areas of high stress which must be 
mechanically relieved to improve crankshaft strengths in these otherwise 
weakened areas. Various arrangements of floating jaw units are employed at 
each journal to mechanically roll the fillets and relieve such stresses 
and strengthen them. 
Generally, each jaw unit has opposing upper and lower jaw arms, which are 
pivotally connected to one another. The jaw arms have facing jaws that are 
adapted to close about a journal during the deep rolling operation. A 
hydraulic cylinder is disposed between the opposing end of the jaw arms 
and is adapted to open and close the facing jaws about the journal and 
apply a working force to the fillets. More particularly, the jaw of the 
upper arm has tooling which includes rollers which engage and mechanically 
work the journal fillets while the opposing jaw of the lower arm has 
tooling with support rollers that support the journal during fillet 
rolling. Accordingly, a portion of each jaw unit and the tooling must be 
in close proximity to the journal and hence the interfacing side wall of 
the counterweights or other part of the crankshaft while the journal 
fillets are being rolled. 
Prior to the present invention, a linkage has been operatively connected to 
the lower arm or jaw to limit any tendency of the jaw assembly to move 
laterally relative to the journal that, for example, may result from a 
taper of the journal. However, even with such a linkage, lateral movement 
may occur to such an extent that the flanks or sides of the counterweights 
or other adjacent portions of the crankshaft are contacted and abraded by 
the tools or a portion of the jaw assembly. This may cause crankshaft 
damage and result in part rejection of the crankshaft and re-machining or 
scrapping of the part. The fillet rolling tools can also be damaged from 
such contact during deep rolling resulting in production down time for 
machine repair and tool replacement. 
SUMMARY OF THE DISCLOSURE AND ADVANTAGES 
The present invention seeks to overcome such problems by improving control 
over any tendency of the crankshaft to move laterally during fillet 
rolling by providing a new and improved lower crankshaft support tool 
which is carried by the lower jaw arm. The lower support tool includes 
laterally spaced large diameter annular flanges which operatively fit into 
the annular undercuts or fillets at both sides of the journals of a 
crankshaft to contact portions of these undercuts to limit lateral 
shifting of the crankshaft relative to the tooling to improve rolling 
operation. The upper tool and other components of the jaw assembly may be 
substantially the same as the prior art. 
According to one preferred embodiment of the present invention, there is 
provided a lower support tool adapted to prevent lateral movement between 
the crankshaft and the jaw assembly of the fillet rolling machine, which 
can be used with or replace the lateral movement control linkage of the 
prior art. The lower support tool includes a roller support housing that 
is adapted to be attached to the lower arm of a journal fillet rolling jaw 
assembly. The roller support housing has two spaced apart transverse 
circular apertures therethrough. A roller unit having a pair of spaced 
apart flanges extending outwardly from its outer cylindrical surface is 
associated with each aperture. A crankshaft journal is disposed between 
and is supported by the roller units, and more specifically, by the 
cylindrical surface of each unit. The flanges of each roller unit align 
and fit into and coact with the opposing journal fillets when the 
crankshaft journal is supported during rolling. Thus the modified lower 
support tool of the present invention laterally locates the journal, and 
hence the adjoining surfaces and counterweights, relative to the lower 
support tool thereby preventing the jaw assembly from laterally moving 
relative to the crankshaft and contacting and abrading such surfaces and 
the sides of the counterweights. 
An object, feature and advantage of this invention is to provide a new and 
improved work support tool for use in fillet rolling equipment for rolling 
annular fillets of journals of engine crankshafts. The support tool 
preferably has a pair of centralized cylindrical support wheels that rolls 
and contacts and support the journal as the crankshaft is being turned and 
further has laterally, spaced retainer flanges for operatively fitting 
into the laterally spaced and annular undercuts on opposite sides of a 
cylindrical journal of the crankshaft. The laterally spaced retainer 
flanges having diameters greater than the diameter of the annular journal 
contact surface and are operative to limit the lateral (axial) movement of 
crankshaft relative to said support tool to reduce or eliminate damage to 
the crankshaft by the tooling. 
Another object, feature and advantage of the present invention is to 
provide a new and improved apparatus that rollingly supports a crankshaft 
whose fillets are being rolled for preventing lateral movement and 
unwanted contact and wear between the jaw assemblies including tooling of 
fillet roll equipment and side faces of the crankshaft counterweights to 
avoid damaging the crankshaft. 
Another object, feature and advantage of the present invention is to 
provide a new and improved lower support tool that can be used with the 
prior art components of the jaw assembly to improve crankshaft fillet 
rolling.

PREFERRED EMBODIMENT OF THE INVENTION 
FIGS. 1 and 2 diagrammatically show portions of a metal working machine 10 
illustrating some construction and principals of deep roll strengthening 
of the fillets of journals 12 of a crankshaft 14. The crankshaft engine 
can be rotatably driven about horizontal axis B by a drive motor 24 
supported by a mounting collar 26 on the machine housing and drivingly 
connected to the chuck 18 by drive shaft 28. The pin journals for the 
engine pistons have side-by-side and coaxial journal portions 30 and 32 
(FIG. 1A) providing cylindrical bearings for the connecting rods 34, 36 
(FIG. 1B) of opposing pistons in the left and right cylinders of V-block 
engines. 
In view of the fact that the pin journal portions 30, 32 as well as the 
main journals experience high stress loads during engine operation, they 
are strengthened in various ways such as by deep roll hardening the radii 
of the undercuts of the laterally spaced annular fillets F, F.sup.1 of the 
pin journal. Deep rolling directs high, concentrated forces to the annular 
fillet areas F, F.sup.1 of the crankshaft 14. Such rolling produces 
compressive strengthening stresses in the metal of the crankshaft fillets 
that may, for example, extend to a depth of 4 mm. 
As illustrated in FIG. 2, this is accomplished in the machine 10 by upper 
and lower tools 40 and 41 operatively mounted in the facing jaws 42, 43 of 
the pivotally interconnected arms of a load applying jaw assembly 44 
forming a part of the machine. Jaw assembly 44 as well as others not shown 
are supported for operation by flexible support 45, diagrammatically 
shown, in a housing H accessed by hinged panel P. 
The upper tool 40 has a pair of floating rollers 46, 46' of hardened steel 
or other suitable material which generally turn on oppositely inclined 
axes A and A.sup.1 to engage and roll the laterally spaced fillets F, F' 
providing the annular joint areas or fillets between the journals and the 
adjacent counter weights or thrust faces of the crankshaft. 
The lower tool 41 illustrative of the prior art has spaced support rollers 
47 that provide the bearing and support for the journals as the crankshaft 
14 is being rotatably driven about its axis B and the fillets are being 
rolled. Rolling pressure is hydraulically applied by the expansion force 
of a hydraulic cylinder 48 operatively connected between the extending 
ends 49, 50 of the upper and lower jaw arms 51, 52 pivoted together by a 
clevis mounted pivot 53 disposed at an intermediate position along the 
length of the jaw arms. This arrangement provides the mechanical advantage 
that amplifies the jaw closure force exerted to the jaw assembly by the 
expansion force of the hydraulic power cylinder 48. 
In an automated machine and by virtue of the flexible support 45, the upper 
and lower jaws and their tools are supported to float around the axis of 
the orbiting journals during rolling. Rolling pressure exerted by the 
rollers 46, 46' can be increased and decreased by cylinder 48 during 
rotational drive of the crankshaft by motor 24 to impart concentrated 
annular residual stress patterns in the metal of the fillets F, F.sup.1. 
These fillets are among the most highly stressed cross-sectional areas of 
the crankshaft in engine operation. The amount of pressure as well as the 
number of over rolls of the fillets can be preselected to roll compressive 
stresses into the metal and produce an optimized fatigue strength. 
Prior to the present invention, linkage L diagrammatically shown in FIG. 2 
has been operatively connected to the lower jaw 43 to limit any tendency 
of the jaw assembly and its tooling from lateral movement M relative to 
the pin journal 30, 32 that, for example, may result from a taper of the 
journal. However, even with such a linkage, lateral movement may occur to 
such an extent that the flanks or sides of portions of the crankshaft such 
as the counterweights or thrust faces of the crankshafts are contacted and 
abraded by the tools 40, 41. This may result in crankshaft part rejection 
and remachining or scrapping of the part. 
The present invention is drawn to a new lower tool 141 which can be 
utilized with a jaw assembly such as assembly 44 to augment linkage L and 
the lateral movement control that it provides. The tool 141 can also be 
used with a jaw assembly such as 144 of FIG. 3 in which linkage L is 
eliminated since the support tool alone sufficiently eliminates lateral 
movement of the crankshaft for high quality fillet rolling. The upper tool 
140 and rollers 146, 146' and other components of the jaw assembly 144 of 
FIG. 3 may be substantially the same as the jaw assembly of FIG. 2. 
FIGS. 3 through 5 illustrate details of the new lower tool 141. This lower 
tool comprises a roller support housing 150 having an elongated base 
portion 152 with a mounting groove or key way 154 for attachment to the 
lower jaw arm 143. Extending upwardly from the base portion 152 is a 
flattened and centralized roller supporting web 164 provided with a pair 
of transversely directed annular openings 166, 168 therethrough (see FIGS. 
4A and 4B). These openings receive the cylindrical shanks or hubs 169 of 
the compound support roller units 170 spaced from one another as shown in 
FIG. 4. Each of these roller units 170 comprises a first roller section 
172 with a large diameter outer cylindrical surface 174 for contact with 
the journal and the smaller diameter shank portion 169 extending axially 
from the first roller section 172 through the associated transverse 
opening 166 or 168. A second roller section 176 is secured to the end of 
the shank 169 by threaded fasteners 178. The outer cylindrical surface 177 
of the second roller section also provides rolling support with the crank 
pin journal. The roller units 170 are rotatably supported in the central 
web of the housing 150 by annular needle bearing units 179. 
FIG. 5 best shows the laterally spaced annular retainer flanges 181, 183 
which extend outwardly in a radial direction from the edges of the outer 
cylindrical surfaces 174, 177, respectively, of the compound roller. These 
annular flanges 181, 183 defining opposite sides of the support roller 
units 170, 170 have increased diameter as compared to the diameter of the 
journal bearing surface provided by cylindrical surfaces 170, 174 of the 
roller units 170. The flanges 181, 183 are work stabilizing and fit into 
the annular fillets of the journal 196 of the internal combustion engine 
crank 197 which corresponds to crank 14 of FIG. 1. These laterally spaced 
flanges 181, 183 are operative to contact portions of the pin journal 
fillets such as annular sides 199 during fillet rolling and are effective 
to limit the relative lateral movement between the crankshaft and the 
back-up and fillet rolling tools so that there is substantially no contact 
between the tools and the side surfaces 194 of the counterweights 195 or 
other surfaces such as thrust faces 200 that may be present to cause 
abrading or other damage to the crankshaft during the rolling procedures. 
The invention has been described in an illustrative manner, and it is to be 
understood that the terminology, which has been used, is intended to be 
descriptive in nature rather than limitation. 
Obviously, many modifications and variations of the present invention are 
possible in the light of the above teachings. It is, therefore, to be 
understood that within the scope of the appended claims the invention may 
be practiced otherwise than specifically described.