Mecánica

Shrink Fit System...
Thermal Induction
• process-controlled heating
• no overheating on the tool
• quick and accurate shrinking, on and off
• for tools with carbide or steel shanks
• slim design of the chucks through absence of mechanical clamping elements
• higher concentricity (<.0001) through uniform clamping force
• higher clamping forces than conventional adapters
• optimumsuitability for high-speed machining due to symmetrical shape
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The Concept:
Heat shrinking processes are not new in the machine tool industry. Only recently, however, has the concept been implemented as a quick-change tool holding mechanism for clamping cylindrical cutting tools that are used in high-speed machining applications.
The internal bore of the Shrink Fit tool holder is manufacturedslightly smaller than that of the cutting tool shank. A quick and precise heat source is applied to the holding end of the tool holder which causes the inside bore to expand. At this point, the cutting tool shank is able to slip inside the bore of the tool holder.
As the tool holder cools, the bore shrinks with uniform pressure and grips the cutting tool shank 360° along the entire length of thebore, resulting in an evenly distributed clamping force.
Due to the nature of the design, flatted, Weldon, and Whistle Notch cutting tool shanks can be used. Mechanical tool holding systems cannot compete, but to gain full benefit from the Shrink Fit technology, fully cylindrical tool shanks are recommended. As long as the heating processes are kept within the elastic range of the tool holdermaterial, this clamping operation can be repeated for several thousand cycles.

Shrink Fit Tooling Advantages:
• Low runout – cutting tools are gripped 360° along the entire length of the cutting tool shank resulting in an evenly distributed clamping force.
• Clamping forces have been found to be greater than those created by collet or hydraulic chucks.
• During testing, cutting tool materialproperties break down and shear before slippage occurs.
• Slim and short toolholder profile designs are achievable because no mechanical moving parts are employed.
• Shrink Fit toolholders are more acceptable in high-speed operations because their absolute symmetry of form provides the best possible balance.
• No special sealing stop screws are required – the designed interference between thecutting tool and the Shrink Fit holder forms a seal that allows coolant to flow only through the designed passages.
With all of the above mentioned design features, the use of Shrink Fit technology allows for greater speeds and feeds, produces better finishes, delivers increased tool and spindle life, and results in greater productivity.

Heat Activating Systems:
There are induction, hot-air andopen flame heating systems on the market today, but the easiest and fastest is the induction method. Shorter cycle time, less cooling downtime, localized heating and integrated cooling systems are essential for a safe and simple system. Low noise, low cost, and an integral pre-setting option are advantages to be considered when deciding on a Shrink Fit system.

Applications
Cylindrical ShankOptions
• Full cylindrical shanks are recommended.
• Flatted, Weldon, and Whistle Notch designed cutting tool shanks can be used.

Heat-up Your Profits . . . Shrink Your Costs with Kennametal’s New Induction Heating (Shrink Fit) System

Toolholders
• Slim design • Balanced
• Small counterbore in front of toolholder allows cutting tool to be held in position before the heat/shrinking processis activated.
• Weldon, Whistle Notch, and flatted-style shanks can be gripped successfully, however, best results are
obtained with smooth cylindrical shank cutting tools (without flats and notches).

Heater Unit
• The table top design is (24" x 24") (610 x 610 mm), and weighs less than 95 lbs (45 kgs).
• Induction coil generator produces concentrated, alternating magnetic fields which, in...