calculation of force to lift a body

[Dexster]

hello to all

I'd like a little help. to calculate the force necessary to lift a body as from attached box. . .

practically is an arm with an applied load on the tip that rises and lowers through a pneumatic cylinder.

the data I know is
weight to be raised in my example 100 kg but can be also 50 kg
the cylinder (allocation 100)
cylinder drive bar (8)
distance between the rotation pin and the cylinter connection point (distance a)
distance between the cylinder connection point and loading point (distance b) [I do not indict them because I practically do not know them yet sincerely)
the cylinder is mounted in a sloping position but the axis of the stem is hypothetically 50/60.

I never studied mechanics to know before
I thank in advance anyone who can help me or explain me to make me understand. .

Thank you.

 

[sail]

Bye-bye

we start from the simplified case, we do it in three steps.

1) find the vertical component of the force that will have to exercise the wound
2) convert vertical force into the cylinder axis force
3) check that the cylinder actually has a sufficent force.

1) to find the vertical component you must balance the moments to the pivot. the moment generated by the weight will be mpeso=weight*(dista+distb) and the motion given by the piston mpist = fv(?)*dist

having said mpeso=mpist we will have weight*(dista+distb)= fv(?)*dista
the vertical force is fv(?) = weight*(dista+distb)/dista

2) at this point it is necessary to correlate the vertical force with that carried out by the cylinder along its axis with a little trigonometry

3) knowing that the force exercised by a cylinder is f=pression*area you can check that the piston is sufficent.

Note that all this is worth the case as a drawing, so the cylinder manages to sustain the weight.
it will be necessary to estimate the most heavy case to check that during the rise or lowering of the beam the force is sufficent. Moreover, no verification of the piston rod, pins, beams etc has been made. security factors are left out of the calculation. I have not taken into account the fact that under weight a Christian could be found (cf. various directives and norms)


and, more important than all, I'm writing at 4:00 a.m., so some notion could have slipped under the pillow.

 

[Fulvio Romano]

and, more important than all, I'm writing at 4:00 a.m., so some notion could have slipped under the pillow.

Maybe even the clock is almost 5.00. .

 

[Fulvio Romano]

However, it is a third lever.
means that it is solved very simply with:
f(vertical) = 100kg*(a+b)/a

However...the distances a and b are put to canis member. I mean from the fulcrum to the cylinder and b from the cylinder to the weight.

knowing the alpha angle of the piston (0° when horizontal), its strength will be:
f = f(vertical) / sen(alpha)

and you should find yourself with the same sail numbers.

consider above all the last note of the sail post, it is very important.

 

[sail]

Maybe even the clock is almost 5.00. .

At least that I said right, I'm in another time zone (even melted in the side, but...):tongue:

 

[meccanicamg]

allego calculation solution for the cinematism in question:

- teta angle that commands the system
- calculation formulas according to the roof to determine the forces if necessary if it is necessary to apply a proportional valve for the lift
- always vertical f force thanks to a hinge system where applied the load (fire, chain, pin with hook)
- minimum diameter determination for lifting cylinder
- formulas valid with max = 90°

notes:
- apply an increase factor appropriate to the cylinder and/or foresee correction of working pressure
- minimize friction otherwise oversized
- verify the structure and components if they return to the forces in play
- predict a system of anti-duty with special pressure controlled safety valves

 

[PaoloColombani]

I never studied mechanics to know before

It's never too late.

 

[Dexster]

thank you all for the information.. tomorrow I will try to see what I throw out

in case I break the boxes again

Dexter

 

[puccio70]

I hook up (if I can) to this topic and ask you a question.
I have a hydraulic piston mounted on a lift.
this has an inclination of about 20 degrees and the lift can lift 240 kg.
I would like to understand how much more it can raise the inclination.

I attach photos to show you my case.

Thank you.

 

[gtemp]

I invite you to read this discussion too
http://www.cad3d.it/forum1/showthread.php?t=33967&page=2