| Summary: | 碩士 === 國立成功大學 === 機械工程學系 === 86 === The device that auotmatically performs tool changes between
thespindle and the tool magazine of a machining center is called
automatictool change mechanism. This work develops a systematic
methodology todesign and analyze an automatic tool change
mechanism for one specifictype of horizontal machining centers.
Based on Yan''''s creative mechanismdesign methodology, a feasible
automatic tool change mechanism thatincludes three subsystems,
the extract and insert tool mechanism, theroller gear cam
mechanism, and the push and pull tool mechanism, is generated.
For each subsystem, the universal motion curve and the input-
outputtime diagram are used to design the motion curve of the
cam. Coordinatetransformation matrix and theory of conjugate
surfaces are used to derivedequations of cam surface and cam
curvature. Based on kinematic and dynamicanalysis of each
subsystem, the joint force, the friction force, and thefriction
torque of each subsystem are analyzed in order to design the
components''''strength and select the bearing types. Finally, the
torque inputand horsepower to drive the mechanisms are derived
from the analyzed model,and are compared with the automatic tool
change mechanism of one specifictype of vertical maching
centers. The theoretical analysis shows that further
improvements of the cam pressureangle of each subsystem and the
torque input of the push and pull tool mechanare need. As
compare with the automatic tool change mechanism of vertical
machining centers, the overall results are close since the
topological structuresof the two designs are similar. The result
of this workis beneficial for improving the prototype automatic
tool change mechanism.
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