Guide Elements
NG gy
LIhnolo in the guidepost or by a retaining Production of quality metal stamp- Upper Anatomy of a Die
TOO c
te
washer that secures to the end of the
guidepost. These components come
ings relies heavily on properly in-
stalled wear plates that have the
shoe
Keeper
in commercial or precision grade. proper clearance for the type of die
For lubrication, stampers should where they are used. Wear plates in- block Ball-bearing
On those jobs that do impart sig- apply a lightweight spindle oil. stall in the heel-block area of the die guide pin
nificant loads onto the bushings, set and guide the pad between the Ball-bearing
toolmakers can use a composite to Wear Strips and Plates upper and lower die shoes. With the retainer
line a steel bushing or bearing. Some Wear strips, of aluminum bronze tremendous amount of energy that a
composites can be used in clean- or bronze-plated steel, typically get stamping press can produce, the Bump Ball-bearing
room applications where no trace of the call when the application re- plates help to avoid die crashes due cam bushing
lubricants or dust can be left behind quires side-to-side or up-and-down to misalignment of pad travel.
to contaminate the end product— movement, for guidance in metal- Upper heel
medical products or food containers, stamping applications as well as for Gibs and Cams block
for example, or where the next pro- machine ways in punch presses. The For heavy-load applications, gibs
cedure would require a clean part, natural lubricity of the bronze sur- made from steel with bronze often Wear plates
such as a painted surface. face resists wear, abrasion and de- are specified as guide elements. For
Sintered materials often are used formation under high compressive less-demanding applications, the Lower heel
as guiding elements—bearings, loads. Wear strips can be provided gibs can be of aluminum bronze plate
washers and wear plates—due to with graphite plugs for mainte- with graphite plugs for constant
their self-lubricating properties. nance-free operation. lubrication.
Lower shoe
Ball Bearings for Speed
Die builders and maintenance
personnel prefer the use U blocks, V blocks, center keys, What’s Next cants. These materials can be mold-
of ball-bearing com- cam-dwell wear plates and guide In the future, manufacturers of ed or formed to suit a particular ap-
ponents because they rails primarily are used in the con- tooling components will be relied plication and are composed of as
ease die construc- struction of custom and standard on to supply products that give utili- much as 80 percent oil, which is im-
tion. High-speed ap- cams used in automotive and home- ty, maintenance freedom, absolute parted at a controlled rate under the
plications require appliance applications. V blocks and interchangeability between a family influence of external forces, elevat-
ball-bearing guide center keys are of hardened alloy of parts and off-the-shelf availability, ed temperatures or capillary action.
components. These consist of steel or aluminum bronze with self- with globally competitive pricing. • Guide bushings, bearings, lin-
three parts: a steel guide bushing, a lubricating graphite plugs. Center- The following exemplify the ers, wear plates and wear strips of
ball cage or retainer and steel guide key guides and U blocks are of hard- processes and products that have graphite-fiber composites. These
pin. The precision balls incorporat- ened alloy steel; all other blocks are been pioneered by tooling-compo- materials can be molded or formed
ed in the cage run tightly between of hardened alloy steel with self-lu- nent manufacturers: to virtually any shape. The material
the pin and bushing, ensuring close U blocks and V blocks find use in special slide applications and as actuating bricating graphite plugs. • Bronze-plated products that is comprised of polyamide resins
tolerances and smooth action. devices, primarily used in the construction of cams for automotive and home- Quality guiding components are combine the strength of the steel with carbon-graphite fibers distrib-
Guide pins for high-speed appli- appliance applications. imperative in cam manufacturing, backing with the lubricity of bronze; uted throughout the section. The
cations are of hardened chrome- whether purchased as a standard • Oil-impregnated plastic bear- unique aspect of the material is a
alloy steel and come as straight pins The length of travel, speed, load Manufacturers produce gibs to off-the-shelf unit or when building a ings and bushings; network of 1-in.-long carbon fibers
or demountable pins. Demountable and mating component that the exacting standards, important for custom cam for a specific applica- • Sintered bearings and bushings; dispersed throughout the resin. The
guide pins and guide bushings offer wear strip will be subjected to helps use in linear slide applications that tion. Cams employ mechanical die • Base-metal alloys plugged with material imparts tensile, flexibility
all of the advantages of straight pins to determine the right thickness, require extreme accuracy. They typ- springs, rubber springs, nitrogen gas graphite for self-lubrication; and compressive strength as well as
and straight-sleeve bushings, with width and length of the wear strip. ically come in lengths to 48 in., with springs or air cylinders to assist in re- • Bushings with liners made of dimensional stability and controls
the convenience of simple assembly These parts function best where the mounting holes for standard appli- turning working slides to their prop- self-lubricating materials; thermal expansion. Self-lubricating,
and disassembly. mating surface is hardened and cations or without holes so the tool- er location after each press stroke. • Wear plates incorporating lay- the composites can be used in wear
Ball-bearing guide-assembly ground. Wear strips typically are maker can drill and mount them for Cam-dwell wear plates are of hard- ers of self-lubricating material and a components subjected to tempera-
bushings also are of hardened 1
⁄8- to 1-in. thick, 1- to 12-in. wide custom tooling. Gibs can withstand ened alloy steel or aluminum bronze metal backing; tures reaching 550 F. The materials
chrome-alloy steel; ball-retainer and as long as 96 in. temperatures to 400 F, and may with or without graphite plugs. • Ball-bearing components. tend to ingest contaminants present
cages are of heat-treated aluminum Wear plates primarily find use in come in square, V and L shapes to Complex multi-angular mecha- Some of the processes and prod- in hostile environments without
alloys or polymers that combine automotive tooling that produces meet specific criteria. nisms, cams require very accurate ucts for use as guiding elements detriment to the wear surface.
light weight and high strength. The medium-sized to large stamped parts. Gib assemblies consist of a base guidance to perform piercing, flang- being considered or under develop- • Aramid fibers that incorporate
ball bearings inserted into the retain- The plates typically are constructed plate with two L-shaped gibs ing and trimming operations. They ment include: high-temperature resin systems are
er cages, and held in place by stak- of steel, steel with graphite plugs, or screwed and doweled to the base. mount to the upper or lower die • Guide bushings, bearings and being considered for bushings and
ing, are manufactured to the quality aluminum bronze with graphite These assemblies find use in special shoes—those that mount to the plates constructed of microporous bearings. This material possesses excel-
AAA1 grade (25-millionth accuracy plugs. Wear-plate thickness ranges slide applications and as actuating upper shoe are called aerial cams, polymer lubricants—solid polymeric lent mechanical strength and dimen-
class). Ball-retainer cages attach to from 0.08 to 1 in., width from 0.20 to devices. those that mount to the lower shoe materials containing interconnecting sional stability when immersed in water,
the guidepost by a setscrew and slot 8 in., and length from 0.20 to 12 in. Guide blocks, keeper blocks, are called die-mounted cams. microscopic pores filled with lubri- acids and chemical solutions. MF
50 www.metalformingmagazine.com MetalForming/March 2002 March 2002/MetalForming www.metalformingmagazine.com 51