3. Advantages of Automation
Reduce human involvement
Reduce work piece damage
Less wastage
Raise the level of safety
Increase productivity
Decrease unit cost
Improve accuracy
More resource utilization
4. Definition of automation
Automation is the use of machines and technology to make process run on their own without
man power.
OR
Automation is the creation and application of technology to monitor and control the
production and delivery of products and services.
5. Principle of automatic control
controller, amplifier, actuator, and feedback.
Open loop & Closed loop control system
8. Difference b/w Automatic and Semi Automatic Lathes
Initial machine set up
Machining operations
Loading of workpiece and unloading of finished products
9. Classification
According to number of spindles
Single Spindle and Multi Spindle Lathes
According Purpose
General Purpose and Single Purpose Lathes
According to Type of Blank
Bar Type and Chucking Types Lathes
According to Arrangement of Spindle
Horizontal Type and Vertical Type
10. Single Spindle Lathes
Single piece of bar stock is fed
Regular shaped bar stocks are processed
Spring collet chuck is used
Friction clutch actuates the collet chuck
12. Single Spindle Automatic Machine
This machine has been developed for manufacturing quantities of small precision components, and is often referred to as Swiss Auto. This
machine is best suited where work is long and slender and where accuracy, finish and concentricity are important.
Fig. 34.2 shows the general layout of sliding head type single spindle automatic machine. The bar stock is fed through a sliding headstock
and held by a collet chuck. It has a sliding headstock which is traversed by a bell or plate type cam. A tool bracket, supporting five tool
slides, each slide, operated by a separate cam, is mounted in the centre. Tool bracket also contains a guide or steady bush for the bar
stock.
Cams are held on a front cam shaft. These control the tool slides and headstock movements. In place of turret slide is mounted a feed
base having single or multi-spindle for operations like drilling, reaming, screwing, tapping, etc.
The main drive is from an electric motor at the bottom left hand of the machine which drives a gear box housed in the cabinet base. From
gear box the drive is transmitted to the spindle by two roller chains which pass up through the base of bed.
Thus the spindle speed can be varied from 60 to 200 R.P.M. in steps. For turning operations the reverse direction of spindle is employed
by use of left hand chain and the slow speed for purpose of screwing and remaining operations is obtained by using right hand chain
drive.
pindle reversal is effected by the operation of the clutch on the spindle and for both the left hand and right hand chains, fast and slow
speed are possible through clutches in the gear box. Thus two forward and two reverse speeds are possible for each combination of pick-
off gears.
The operation of these and the spindle clutch takes place from the back shaft and thus the speeds could be changed or reversed
automatically also. The spindle is mounted in preloaded radial roller bearings which prevent excessive clearance in the spindle over a
prolonged period of operation.
13. Types of Single Spindle Automatic
Machines
1. Automatic Cutting-off Machines
2. Automatic Screw Machine
3. Swiss Type Automatic Screw Machine
14. Automatic Cutting-off Machines
These machines produce short w/p’s of simple form by means of cross sliding tools.
Machines are simple in design.
Head stock with spindle is mounted on bed.
2 cross slides are located on bed at front end of spindle.
Cams on cam shaft actuate movements of cross slide through system of levers.
15. Automatic Cutting-off Machines
Operation:
• The reqd length of work(stock) is fed out with a cam mechanism, up to stock stop which is
automatically advanced in line with spindle axis at each end of cycle.
• Stock is held in collet chuck of rotating spindle.
• Machining is done by tools that are held in slides operating only in cross wise direction.
• Typical simple parts (3 to 20 mm dia) machined on such a machine is shown in fig.
20. Single Spindle Automatic Screw Machine
Bolts & Screws from bar stock
Complex shapes can also made
Cam controlled mechanism is used for clamping, releasing and feeding bar stock.
22. Swiss Type Automatic Screw Machine
Head stock is movable
Tools are fixed
Sliding head type
Mass production of small diameter parts
Precision works – watches, instruments, radio parts etc.
30. Pantograph Copying System
Copy form of involute gear tooth space to grinding wheel of a gear tooth
grinding machine
Follower, fulcrum and tracer must lie in straight line
