Question

Task 3: (20 Marks) The figure 3 represents the power hacksaw used to cut heavy pipes and hard materials се Figure 3: Power Hacksavw a) Explain the working principle of power hacksaw and its application. b) Identify the mechanism used for hacksaw. c) Identify the driving link and generate the kinematic diagram. d) How the vibration on the machine is managed during operation?

Answer 1

a) Working principle of power hacksaw :

It converts rotatory motion of the electric motor to reciprocating (translating) motion of the hacksaw blade which is used to cut pipes and other materials.

b) The mechanism used for hacksaw is Slider - Crank mechanism.

c) The driving link is the one which is attached to the motor.

Kinematic diagram :

suider C blade) Connested tw motoy

d) The vibrations in this machine occur majorly in the cutting process where the blade cuts the metal work piece. This can be experienced while cutting with a normal hand held hacksaw too.

To reduce this vibrations,

1) the speed of oscillation of the blade is decreased using gears at the driving link.

2) extra weight is added in the link which consists of the blade, which basically pushes down the blade onto the work piece, creating a normal force.

3) Sometimes the vibrations also occur due to improper clamping of the work piece. This can be reduced by using proper ways to fix the metal work piece.