What gives hydraulic machines great pressure that it can pressed and mold sheet metals as if they're plastics?

Answer 1

It is really very easy, the same priciples as 'leverage' applied to fluids.
Check out this link.
http://science.howstuffworks.com/hydraulic.htm

Yours: Grumpy

Answer 2

The concept of hydraulics is rather simple. Yet it can get really complicated. hydraulics is the flow of a liquid, its also known as fluid mechanics. heres a simple example, you have two cylinders connected together by an sealed hose or pipe making a pressure system. In this two connected cylinder system is a fluid (hydraulic oil) which tends to be stable and incompressible to a certain extent. If one of these cylinders is twice the size by volume then the other, if you apply a force to this cylinder, the fluid is pushed out of it and into the other, the neet thing is that the second cylinder and exert twice the force you applied to the first. It magnifies force through the fluid and its cylinders. Nowaday cylinders are pumped into motion with the use of electric or mechanically driven pumps at high pressure to activate the cylinders into motion. Well, as you can see, its a science unto itself and can be talked about at length. If your interested, look up the theories and writings of Pascal and Bernoulli, two smooth and slick fellows.

Answer 3

Hydraulic Pressure, it's not that different than your Brakes on your car.

If you have power brakes the hydraulic pressure in your wheel cylinders can easily exceed 2000 pounds per square inch and that pressure pushes the brake pads against the metal rotors and the friction stops you.

By using the right multiplication factors in designing a Hydraulic press you can get pressures in 100's of tons.

Answer 4

Pistons inside hydraulic cylinders compress the liquid (usually oil) to create the enormous pressures. This is tranferred on to the metal sheet spread over a Die (with all the contours) and a die cushion for support from below, to get the required form.

Do you know that this can be done also using water - however with a different type of machinery and process.

Answer 5

With the assumption in classical fluid mechanics that a fluid exerts pressure on its container perpendicular to the plane of the container walls and equally throughout the fluid, engineers are able to use this phenomenon to create large forces.

We know from basic mechanics that Force on Area is equal to pressure (F/A=P). This means that for a certain pressure, if we increase the area that pressure acts upon, we can create a larger force (F=P*A from above).

So if we place a fluid under pressure by increasing our force input into the fluid system, and minimising the area that this force acts upon we can create a large pressure. We can have this pressure act on a large area within the system to create a large force that can be used for useful work such as machine part forging. Some industrial stampers create forces in the magnitude of hundreds of tonnes (Mega Newtons) through this force magnification method found in fluid/hydraulic systems.

Answer 6

Hydraulic fluid (as with all liquids) exert pressure evenly in all directions when it is under pressure. The secret to the great forces is the area of the piston that the pressurized fluid is pressing against. Just a mere 10 pounds (PSI) of pressure against a small 10 sq. in. pistion will push the piston forward with 100 pounds of force! (10 pounds per square inch times 10 square inches) You can imagine the forces generated with hundreds or thousands of pounds of fluid pressure against a very large pistion.

Answer 7

its called hydralic multiplication. a large motor runs a pump with a small diameter cylinder. the pump only pumps a small volume of fluid, but can pump at a great psi with little effort. the pump then runs a large diameter hydraulic cylinder. say the diameter of the pump is 10% the size of the cylinder it is driving. the cylinder is 10 times larger than the pump right, this means that if the pump has 10 pounds of force applied to it the cylinder will exert 100 pounds of force, however, say you have two cylinders(one is 10 times larger than the other) if the small cylinder gives up one gallon of fluid per foot, then the large one must receve 10 pumps(gallons)from the small cylinder to travel one foot. this is why it is pocible for a small child to lift a large truck with a hydraulic jack. its just like gearing something down. it gets more force, but must travel a longer distance. thanks to hydraulic multiplication, we have machines that can crush large cars into small blocks of metal. if you have ever seen a strand jack you will know that they can lift increadable amounts of weight with a relitively small motor, it just takes a while.

Answer 8

Mostly because the machines can withstand a lot of pressure and force, and when they release it, the sheet metal can't withstand it, so it gets cut or pressed in whatever way the machine was designed to do.