MACHINE DESIGN 1 (SUBJECT) Cutting tools such as mills and drills are connected to machining equipment by means of tool holders. The cutting tool must be firmly clamped by the tool holder to achieve precise machining, and shrink-fit tool holders take advantage of thermal expansion properties to achieve this strong, concentric clamping force. To insert a cutting tool, the shrink-fit holder is rapidly heated while the cutting tool remains at room temperature. When the holder has expanded sufficiently, the cutting tool drops into the holder. The holder is then cooled, clamping the cutting tool with a very large force exerted directly on the tool shank. At 20°C, the cutting tool shank has an outside diameter of 18.000 0.005 mm and the tool holder has an inside diameter of 17.950 0.005 mm. If the tool shank is held at 20°C, what is the minimum temperature to which the tool holder must be heated in order to insert the cutting tool shank? Assume that the coefficient of thermal expansion of the tool holder is 11.9 10−6 /C. MINIMUM Temperature, o C Supposing the tool holder rotates 500 rpm, what will be the shearing stress of the cutting tool given that the power is ¼ hp.
MACHINE DESIGN 1 (SUBJECT)
Cutting tools such as mills and drills are connected to machining
equipment by means of tool holders. The cutting tool must be firmly
clamped by the tool holder to achieve precise machining, and shrink-fit tool
holders take advantage of thermal expansion properties to achieve this
strong, concentric clamping force. To insert a cutting tool, the shrink-fit
holder is rapidly heated while the cutting tool remains at room temperature.
When the holder has expanded sufficiently, the cutting tool drops into the
holder. The holder is then cooled, clamping the cutting tool with a very large
force exerted directly on the tool shank.
At 20°C, the cutting tool shank has an outside diameter of 18.000
0.005 mm and the tool holder has an inside diameter of 17.950 0.005
mm. If the tool shank is held at 20°C, what is the minimum temperature to
which the tool holder must be heated in order to insert the cutting tool
shank? Assume that the coefficient of thermal expansion of the tool holder is
11.9 10−6 /C.
MINIMUM Temperature, o C
Supposing the tool holder
rotates 500 rpm, what will
be the shearing stress of the
cutting tool given that the
power is ¼ hp.
Trending now
This is a popular solution!
Step by step
Solved in 3 steps
