The Working Principle of The Hydraulic Press Machine

Working principle

A hydraulic press is a compression device that makes use of an exerted force placed upon a fluid, to create a resulting force according to Pascal's Law. It was actually invented by Joseph Bramah, so is also known as the Bramah Press.

What is Pascal's Law? The Hydraulic Principle explained.

Pascal's Law is a theory which states that the pressure (P) in a confined fluid, caused by a force (F1), over an area (A1), is transmitted undiminished, causing a force (F2), over the area (A2). This law can be applied to magnify a small force by the ratio of the areas to give a larger force – F2 = F1 (A2/A1).

How does a hydraulic press work? Pascal's Law in action

In a hydraulic press, a modest mechanical force (F1) is applied to a small area (A1). As the fluid is moved in one location, it inevitably moves elsewhere within that channel. Then a larger area (A2) generates a magnified mechanical force (F2). The force is transmitted via hydraulic pressure generated by the initial effort, F1.

The basic principle of four pillar hydraulic press machine is the oil pump to delivery the hydraulic oil to the integrated cartridge valve block, the hydraulic oil will be distributed to the upper or lower chamber through the one-way valve and the relief valve, the cylinder will move under the action of high pressure oil. 

The four column hydraulic press machine is the device to use of liquid to transmit the pressure. The liquid follows the Pascal's law when the fluid is delivered in a closed container. The hydraulic drive system of the four-column hydraulic press consists of the power system, the control system, the implementing system, the auxiliary system and the working medium. 

The power system is usually adopt oil pump as power system. In order to meet the requirements of the speed of the implementing system, the machine use one or several oil pumps: 

⒈ Low pressure (oil pressure less than 2.5MP) use gear pump; 

⒉ Medium pressure (oil pressure less than 6.3MP) use vane pump; 

⒊High pressure (oil pressure less than 32.0MP) use piston pump. 

Pressure processing and forming of various plastic materials, such as the extrusion, bending, drawing and cold forming of stainless steel plates, as well as the pressing of powder products, grinding wheels, bake lite and resin thermo setting products.

In nowadays, the hydraulic press machine, especially the 4 column hydraulic press machine plays a very important role in the industry production, so choose a professional sheet metal CNC machine manufacturer is a crucial factor to the machine quality. 

Working medium:

The function of the working medium used in the hydraulic press is not only to transmit the pressure but also to ensure that the working parts of the machine are sensitive, reliable, long-lived, and less leaking. 

The basic requirements of hydraulic press for working medium are:

①It has suitable fluidity and low compressibility to improve transmission efficiency;

②Can prevent corrosion;

③Has good lubrication performance;

④Easy to seal;

⑤ Stable performance, long-term work without deterioration.

The hydraulic press initially uses water as the working medium, and later it is changed to an emulsion made by adding a small amount of emulsified oil to the water to increase lubricity and reduce rust. In the late 19th century, hydraulic presses using mineral oil as the working medium appeared. The oil has good lubricity, corrosion resistance, and moderate viscosity, which is beneficial to improve the performance of the hydraulic press. In the second half of the 20th century, a new type of water-based emulsion appeared. Its emulsified form was "water in oil" instead of the original "oil in water". The outer phase of the "water-in-oil" emulsion is oil. Its lubricity and corrosion resistance is close to the oil, and it contains very little oil and is not easy to burn. However, water-based emulsions are more expensive, which limits their promotion.

The hydraulic press machine applied areas:

1. Assembly Operations: Presses are used for the assembly of parts through pressing bearings, assembling shocks, and other components.

2. Sheet Metal Work: Creating body panels, frames, and other structural components of vehicles.

3. Repair: Straightening bent frames and chassis or pressing out/in bushings and bearings during vehicle maintenance.

4. Component Manufacturing: Forming and shaping of structural components made from high-strength alloys that require precise control.

5. Producing Construction Materials: Making components like metal beams, pipes, and plates.

6. Pattern Imprinting: Hydraulic presses are used for imprinting designs on jewelry and for compacting precious metals into desired shapes.

7. Metal Forming: Hydraulic presses are extensively used for bending, stamping, and deep drawing of metal sheets. This includes forming car bodies, kitchen utensils, and other metal parts.

8. Forging: They are ideal for forging operations where high pressure is needed to shape metal using dies.

9. Molding: Used in the compression molding of plastics, composites, and other materials. They help in manufacturing various consumer goods, automotive components, and industrial parts.