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Describe how the linkage system controls the throttle lever of the carburettor, as shown opposite - Leaving Cert Engineering - Question 8 - 2014
Question 8
Describe how the linkage system controls the throttle lever of the carburettor, as shown opposite. (a) (b) Describe any three of the following: (i) The difference... show full transcript
Worked Solution & Example Answer:Describe how the linkage system controls the throttle lever of the carburettor, as shown opposite - Leaving Cert Engineering - Question 8 - 2014
Step 1
Describe how the linkage system controls the throttle lever of the carburettor, as shown opposite.
Answer
The linkage system facilitates the movement of the throttle lever in response to the pedal action. When the pedal is pressed, it results in a movement of linkage B, which pivots around point A. This action causes the throttle lever to adjust, thereby modifying the amount of air and fuel mixture that enters the carburettor. The linkage works in a manner that allows the throttle lever to return to its original position through the assistance of a spring connected to the pedal, ensuring smooth and controlled engine response.
Step 2
Describe any three of the following: (i) The differences in operation between a single-acting cylinder and a double-acting cylinder in pneumatic control.
Answer
A single-acting cylinder allows air pressure to act in one direction only, meaning it can extend but requires a spring or external force to return to its original position. Conversely, a double-acting cylinder can operate in both directions, receiving compressed air for both extending and retracting movements, resulting in more versatility in applications.
Step 3
Describe any three of the following: (ii) The operation and application of a rack and pinion system.
Answer
In a rack and pinion mechanism, the rotation of a circular pinion gear converts into linear motion of a rack, which is a straight bar with gear teeth. This system is widely used in steering systems of vehicles where the driver's steering wheel turns, consequently moving the vehicle's wheels. Additionally, it is also employed in various machinery for linear positioning.
Step 4
Describe any three of the following: (iii) One application of reciprocating motion.
Answer
Reciprocating motion is commonly seen in piston engines, where the piston's linear motion transforms into rotational motion of the crankshaft. This fundamental movement is crucial for the combustion process, enabling the engine to convert fuel into mechanical power required for vehicle operation.
Step 5
Describe any three of the following: (c) It is proposed to design a model based on the DeLorean DMC-12 sports car shown. Describe, with the aid of a suitable diagram, a mechanism that would allow the gull-wing doors in the model to open and close.
Answer
To design the gull-wing doors for the model, we can employ a gear mechanism connected to a driving motor. When the gear is activated, it will rotate and lift the gull-wing doors upwards. The system would include a switch that allows the motor to reverse, enabling the doors to close. This design not only provides mechanical advantage but also allows for smooth operation of the doors, mimicking the full-scale vehicle.