Malfy
Guest
Bye to all,
I went back to doing a technical job after years from "commercial" and I have a lot of rust to shake off me!
I have a seemingly trivial problem, but from which I can't get out... and I'm afraid I'll have other questions to ask in the next few days, I hope there's someone among you who wants to help me get back fully operational
So... in reference to the attached images, I describe the problem:
in the first picture, the side view of a mechanism operated by a press is observed. the towel has a triangular cam drawn of cutter that pushes on the nottoline b (it is a plug with around a free bushing to rotate) and moves vertically inside a driving exhaust obtained in the body c. the plate receives the push of the press and is a guide column.
the notton b drives a cart (not represented) that moves horizontally from right to left.
I need to calculate the force etched to the cart from the cam and know the maximum force of the press.
I initially realized the pattern of figure 2, neglecting the binding reactions because it is assumed that the body is properly dimensioned.
I have considered the force f of the press applied to the point of contact between the cam and the nottolino b and the illustrated compositions I have obtained the resulting r. the cacolo is trivial and will be f2=fsin30° from which r=f2cos30°.
the problem was born when I dwelt on the vine-madrevite scheme of figure 3 which is very similar to my mechanism.
we read that q=r2cos (alpha + phi). r2 is actually my f2 less than the friction angle I initially neglected because the dynamic friction coefficient for steel on lubricated steel corresponds to a little lower than the 3rd and I do not need the absolute precision of calculations. if I exclude friction even in the example of figure 3 then r2=n, then q=ncos(alfa) and f=nsin(alfa). Comparing my results with the latter is an obvious incongruence in the value of the normal force to the cam.
for me it is f=f2/sin (alpha) and this greatly changes the varole of my resulting r. yet it seems intuitively strange that my f2 may be bigger than f...
What and where am I wrong?
thank you all in advance for the help!
I went back to doing a technical job after years from "commercial" and I have a lot of rust to shake off me!
I have a seemingly trivial problem, but from which I can't get out... and I'm afraid I'll have other questions to ask in the next few days, I hope there's someone among you who wants to help me get back fully operational
So... in reference to the attached images, I describe the problem:
in the first picture, the side view of a mechanism operated by a press is observed. the towel has a triangular cam drawn of cutter that pushes on the nottoline b (it is a plug with around a free bushing to rotate) and moves vertically inside a driving exhaust obtained in the body c. the plate receives the push of the press and is a guide column.
the notton b drives a cart (not represented) that moves horizontally from right to left.
I need to calculate the force etched to the cart from the cam and know the maximum force of the press.
I initially realized the pattern of figure 2, neglecting the binding reactions because it is assumed that the body is properly dimensioned.
I have considered the force f of the press applied to the point of contact between the cam and the nottolino b and the illustrated compositions I have obtained the resulting r. the cacolo is trivial and will be f2=fsin30° from which r=f2cos30°.
the problem was born when I dwelt on the vine-madrevite scheme of figure 3 which is very similar to my mechanism.
we read that q=r2cos (alpha + phi). r2 is actually my f2 less than the friction angle I initially neglected because the dynamic friction coefficient for steel on lubricated steel corresponds to a little lower than the 3rd and I do not need the absolute precision of calculations. if I exclude friction even in the example of figure 3 then r2=n, then q=ncos(alfa) and f=nsin(alfa). Comparing my results with the latter is an obvious incongruence in the value of the normal force to the cam.
for me it is f=f2/sin (alpha) and this greatly changes the varole of my resulting r. yet it seems intuitively strange that my f2 may be bigger than f...
What and where am I wrong?
thank you all in advance for the help!
