BASIC CIRCUITS – EXERCISE AND TROUBLE SHOOTING
INTRODUCTION:-
Basic circuits are assemblies of valves to perform certain functions. There are some elementary functions by which even the most sophisticated circuits are composed.
These functions can have the ability to:
- Control a cylinder or
- Operate another valve
The functions are applied:
- For remote control from a panel,
- To change one valve function into another
- For safety interlocks etc.,
Exercise -1
By pressing a pushbutton, articles are pushed away from the gravity feed magazine into a conveyor system. A single acting cylinder is to facilitate this. When the push button is released, the piston rod returns to its start position. Draw the circuit diagram for the problem.
Exercise -2
A heavy door is to be opened pr closed by a double acting cylinder, with the opening and closing signals given by a lever operated hand valve. Design and construct a pneumatic circuit to achieve this.
Exercise -3
Bulk loose material is to be emptied from a dump hopper. By pressing a push button P1, the dump hopper is tilted and the bulk loose material is emptied out. By pressing another push button P2, the dump hopper is returned to its initial position.
Additional Condition: Signal P2 should have priority over p1. i.e. if both are pressed together cylinder should return to retracted condition.
Exercise -4
In a production process, work pieces are to be fed into a jig from a gravity magazine by using a double acting cylinder.
Feeding takes place when a push button is pressed and return automatically to its start position after the work piece has reached the jig position.
Exercise -5
A huge steel door is installed in a deep mining tunnel. This door may be opened or closed by two push buttons, either from outside or inside.
Exercise -6
The tested parts are distributed to three conveyors (Good/Reject/Rework), shifting to the required positions must be possible in any sequence by push buttons.
Exercise -7
Parts are to be punched using a double acting cylinder via mechanical linkage. Punching is only possible when the work piece is in position (mandrel), the safety cover closed and either a push button o afoot pedal is actuated. After the punching cylinder has reached the rear end position, it is automatically returned to its extended position. Both ways the cylinder speed are to be very fast.
7. SYMBOLS – APPENDIX
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