Machine tool constructions Flashcards
1
Q
Types of Frames
A
- Welded sheet metal frames
- Cast iron frames
- Concrete frames
2
Q
Factors affecting construction
A
- Motion axis orientation and length
- auxiliary equipment location
- static, dynamic and thermal loads
- manufacturing costs
3
Q
Machining center and press frame types
A
C type
O type
(vertical and horizontal machining centers)
4
Q
Parallel kinematics machines
A
- Hexapods
- axis motion is achieved by changing length of links with joints in their ends
- no guideways
5
Q
Roller guideways
A
- fast feed motions
- modest cutting forces
- low friction
- wear quickly
- damping not good
- load capacity not that good as slideways
6
Q
Drive systems
A
- Screw/nut construction
- ballscrews
- Rack and pinion and worm wheel
- direct AC drives
7
Q
Linear motors pro/con
A
+ no backlash
+ no vibration because no long screws
- difficult to cool
- no gearbox: limited acceleration and braking forces
8
Q
Machine tool automation techniques (for long unattended operation): tool setup
A
- fixed tool setup in magazine (up to 200 slots)
- slots with non-standard part specific tools
- duplicate (spare) tools are automatically taken to
- worn or broken tools are changed manually
9
Q
Machine tool automation techniques (for long unattended operation): workpiece changing
A
- in machining centers: parts are manually clamped on pallets and pallet changer is used
- in turning: roboter and bar feeder
10
Q
Machine tool automation techniques (for long unattended operation): measuring
A
- in-process measuring in circular grinding
- turning and machining centers: measuring finished part in the machine with probe tool or at external measuring station
- tool wear compensation or other minor adjustments
11
Q
Purpose of a measuring probe
A
• Allowance
• Workpiece location (zero
point)
• Dimensional control
