Do you know the dimensions of a hydraulic press? Not all machine tools are the same: they vary in size, capacity and power, among other parameters. The same applies to hydraulic presses, machines that work on Pascal's principle and are available today, new and used, in a range of sizes.
What is a hydraulic press?
Before discussing the dimensions of a hydraulic press, you should know that these machines are based on Pascal's principle, which dates back to the seventeenth century. According to this principle, the pressure of a liquid contained in a small vessel is transmitted to a larger one to produce a greater force. This is what enables hydraulic presses to move heavy loads and carry out tasks that require great effort.
In line with Pascal's principle, hydraulic presses consist of a series of communicating vessels driven by cylinders or pistons of different sizes using small forces. These move by means of a hydraulic fluid and can generate greater forces. The pistons drive the motor that actuates the presses.
These machines are used to multiply forces and to produce different types of parts through various machining processes such as stamping, pressing and blanking. They are also well suited to mass production.
Choosing by hydraulic press dimensions?
The dimensions of a hydraulic press determine the type of parts it can process and the loads it can withstand. They vary widely: you will find presses that are very large, with beds (the base, or bed) of 5,500 x 3,000 mm and capacities of up to 185,000 kg. The dimensions of a hydraulic press depend on the use you intend to make of it. For example, factories producing very large metal parts, as well as the automotive, aerospace and shipbuilding sectors, need a machine capable of handling high tonnages.
If you want to manufacture smaller parts such as dies and moulds, a machine of compact dimensions will be enough, with a table of between 200 and 400 mm and less power than would be needed to process large parts.
How to choose a hydraulic press
If you are considering a hydraulic press, used or new, there are a number of parameters to take into account before buying. The first step is to determine the dimensions of the hydraulic press, and to do this you need to be clear about your machining requirements:
- Use. Not all hydraulic presses are designed for the same purpose. A small part does not require a large hydraulic press or one that can withstand heavy loads. That is why it is important to know what the machine will be used for.
- Force. The force also depends on the parts to be processed. Small parts do not need as much power as large ones.
- Stroke. The stroke, or stroke length, is the distance travelled by the piston inside a cylinder from bottom dead centre to top dead centre. The stroke determines the working power.
- Size. The larger the tool, the more power it will have.
Parts of a hydraulic press
Table or bed
On hydraulic presses, the table or bed is the machine's primary support and is a flat, fixed surface. The dimensions of the hydraulic press are determined by the table or bed, which must be sturdy enough to withstand the working forces and the weight of the parts.
Bolster plate
This is where the workpiece is placed for processing. It is usually made of steel and is highly resistant to machining forces. The bolster plate is removable and generally requires thermal insulation.
Die cushion
It is called a cushion, but it is actually a hydraulic cylinder positioned beneath the bolster plate that eliminates wrinkles, ensures uniform processing and keeps the operation smooth. It is generally used for deep drawing.
Height
Height is not a component, but it is a parameter to bear in mind: it defines the distance between the bolster plate and the top of the press. It sets the travel of the tool towards the workpiece. The greater the height, the greater the working force.
Frame: it determines the dimensions of the hydraulic press
It houses the hydraulic cylinder, the most important component of the machine, which converts pressure into force. The working surface is also located in the frame. The frame also determines the tonnage the machine can withstand.
Bottom stop and bushing
The stop returns the press to its starting position and can work by pressure or by position. The bushing, for its part, is a lining that controls friction and can be fixed or movable.
Die
The die makes it possible to perform various pressing operations such as bending, stamping, drawing, piercing, shearing, marking and cutting.
Motor and hydraulic components
On hydraulic presses, the motor can be electric or hydraulic. The former converts electrical energy into rotary energy through the hydraulic circuits that drive the hydraulic pumps; the latter converts hydraulic energy into rotary energy using a pump.
The hydraulic power unit uses pressure to actuate the cylinders, motors and other parts of the machine.