Some of these hydraulic presses are mentioned in this article. For precision tooling applications, four-column hydraulic presses are employed. There are four-column, four-beam hydraulic presses, four-column three-beam hydraulic presses, and four-column two-beam hydraulic presses available recently. These presses can be used for heavy duty applications as well.
Hydraulic presses are also classified according to their maximum pressing forces that they can generate. These forces vary from 10,000 pounds (45 Kg) to 50,000 pounds (225 Kg). The highest pressure that can be generated by a hydraulic press is known as its peak pressure. This pressure varies depending on the model of the press.
The main advantage of using a hydraulic press over other pressing methods is that the force applied by the press is directly related to the pressure of the fluid that enters it. This means that more pressure will result in higher pressing forces. Presses use hydraulic or pneumatic systems to generate pressure. These systems are very efficient because there are no mechanical parts involved in generating pressure. Thus, hydraulic presses are very reliable and have long service lives.
There are two types of hydraulic systems used in hydraulic presses: single-acting and double-acting. In single-acting systems, the pressure increases as it goes into the chamber, reaches a certain point, and then decreases again as it leaves the chamber.
Hydraulic presses are often used for activities such as forging, clinching, moulding, blanking, punching, deep drawing, and metal shaping. The hydraulic press is useful in manufacturing because it allows for the creation of more complicated forms while still being material efficient. The hydraulic press can produce parts with a higher quality and lower cost than other methods.
They are also used in mining to process ore, for oil and gas drilling to drill holes in rock (for extraction of oil or natural gas), and in construction for masonry work and as a power tool for heavy duty pressing and cutting tasks.
Presses are usually built to accommodate any number of cylinders, which provide the force for the press. There are several types of cylinders available on the market today: air, electric, oil-powered, and hydraulic.
Air cylinders are the simplest type of cylinder and they use compressed air instead of oil to create force. This type of cylinder requires a source of air that is always available. It is commonly found in small tools where space is at a premium. Air cylinders are not recommended for applications requiring great load capacity or long strokes because they can supply enough pressure to cause damage to other components if placed in compression.
Electricity is used to activate hydraulic cylinders, which then extend or retract under the influence of an electrical signal.
Mechanical vs. Hydraulic Presses
Hydraulic presses offer a significant mechanical advantage. It is the ratio of the area of the big piston to the area of the tiny piston in a hydraulic press. Because area equals dimension squared, a piston 5 times larger applies 25 times greater force. This gives the hydraulic press great power with small physical dimensions.
These advantages come with a cost: Hydraulic presses are also very expensive to buy and operate. They require special tools for set-up and maintenance. Also, they cannot be used indefinitely without replacement parts. Finally, they can leak if not maintained properly.
There are many different kinds of presses available today. The most common type of industrial press is the vertical roller milling machine. These machines have two main components: A base that supports the machine above ground level and an arm attached to the base that holds the rollers. As metal bars or plates pass between the rollers, they are crushed into dust or powder.
Another common type of industrial press is the horizontal roller milling machine. These machines work in much the same way as their vertical counterparts, but instead of having one shaft coming off the end of the base, there are two. One goes up and one goes down. These machines are more commonly used for grinding materials that won't spill if dropped, such as glass or ceramic.
Hydraulic Press Applications
Components of Equipment A hydraulic press contains all of the main components of a hydraulic system. It consists of cylinders, punches (or pistons), hydraulic pipes that transport fluid, and a die (or anvil). The pistons employ high-pressure liquid to push on the anvil with great force. This force is used to print metal or plastic parts from molds. Cylinders Contain the piston inside a cylinder. There are two types of cylinders in use today: steel and aluminum. Steel cylinders are heavy and durable but cannot be used at temperatures below -20 degrees F due to the material's tendency to become brittle when exposed to such low temperatures. Aluminum cylinders are much lighter than their steel counterparts and can withstand temperatures as low as -400 degrees F. They also work better with hydraulic fluids that contain additives to prevent them from bonding to the surface of the cylinder.
Pipes Transport hydraulic fluid throughout the press. Pipes are made of stainless steel or plastic. When hydraulic pressure is applied to one end of the pipe, it expands into the wall of the pipe, providing more space for more fluid to enter or exit. Hydraulic valves control how fluid flows through the system. They can either open or close off sections of pipe so that different areas of the machine are activated during different steps in the printing process. For example, one valve may open up a channel between the pump and the first cylinder while another valve opens up a channel between the second and third cylinders.
A classic mechanical press, in general, may reach the fastest production speeds, especially when operating relatively flat components with simple, shallow shaping needs. A hydraulic press provides more tonnage and working energy variety, allowing for more complicated operations and forming. Hydraulic presses can also be used for finishing tasks that require less pressure than those able to be exerted by a mechanical press.
Mechanical pressing involves the use of heavy cast iron or steel plates as anvils. These are mounted on a frame which is then placed on top of the mold cavity. Mechanical presses are usually built with a single lift system using a crankshaft and flywheel to provide power for both opening and closing the press. As the top plate descends, it forces the mold cavity open. When the mold cavity is closed, the weight of the platen drives the cast iron or steel plate against the metal being formed, squeezing out any excess material that might have accumulated in the die cavities.
Hydraulics presses use oil or water to exert pressure on the platens. Oil-filled presses operate at lower pressures but offer greater control over the amount of pressure applied to each part. Water-filled presses are faster and easier to operate but cannot produce as much force as their oil-filled counterparts. Both types of presses can be used for either mechanical pressing or hydroforming operations.