Introduction and working principle of hydraulic press machine

Hydraulic press is a machine that uses hydrostatic pressure to process metal, plastic, rubber, wood, powder and other products.  It is often used in pressing process and pressing forming process, such as: forging, stamping, cold extrusion, straightening, bending, flanging, sheet drawing, powder metallurgy, pressing and so on.  

• Drive system  

The drive system of hydraulic press mainly has two types: pump direct drive and pump-accumulator drive.  The pump directly drives the pump of this drive system to provide high pressure working liquid to the hydraulic cylinder, the flow valve is used to change the direction of liquid supply, and the relief valve is used to adjust the limited pressure of the system, while playing a safe overflow role.  This drive system links less, simple structure, pressure can automatically increase and decrease according to the required working force, reduce the power consumption, but must be determined by the hydraulic press's maximum working force and the highest speed of the pump and its driving motor capacity.

• Classification:  

According to the structure form is mainly divided into: four column type, single column type (C), horizontal, vertical frame, universal hydraulic press.  

According to the use, it is mainly divided into metal forming, bending, stretching, punching, powder (metal, non-metal) forming, pressing, extrusion, etc. Hot forging hydraulic press

• Four column hydraulic press  

The hydraulic press is suitable for the pressing process of plastic materials.  Such as powder products forming, plastic products forming, cold (hot) extrusion metal forming, sheet stretching and horizontal pressure, bending pressure, turning through, correction and other processes.  

Four column hydraulic press can be divided into four column two beam hydraulic press, four column three beam hydraulic press, four column four beam hydraulic press 

• Single column hydraulic press

Can expand the working range, using three sides of the space, lengthen the stroke of the hydraulic cylinder (optional), the maximum telescopic 260mm-800mm, preset working pressure;  Hydraulic system heat dissipation device. 

• Gantry type hydraulic press
  

Machine parts can be assembled, disassembled, straightening, rolling, stretching, bending, punching and other work, truly realize a machine multi-purpose.  The machine table can move up and down, the size of the expansion of the machine opening and closing height, more convenient to use.  

• Double column hydraulic press  

This series of products are suitable for all kinds of parts of the press-mounting, bending shaping, stamping indentation, flanging, punching and small parts of the shallow    stretching;  Metal powder products forming and other processing technology.  Adopt electric control, with point moving and semi-automatic circulation, can keep calendering time, and has a good slide guide, easy to operate, easy to maintain, economic and durable.  According to the needs of users can be added thermal instrumentation, cylinder ejector, stroke digital display, counting and other functions.

• Usage of hydraulic press machine 

The equipment is especially suitable for bending, forming, flanging and other processes of central load parts, with punching buffer device, can also be used for punching, blanking processing, is the first choice of shipping industry, pressure vessel industry, chemical industry and other industries.  

For sheet metal parts of the stretch forming, turning, bending and stamping process, can also be used for general pressing process, according to the user needs to increase punching buffer, punching, mobile workbench and other devices  

In addition to being used for forging and pressing, the three beam and four column hydraulic press can also be used for rectification, pressing, packing, pressing blocks and plates, etc.  

Also can be used in the forming of axial parts, the profile of the calibration, withhold, installation process and sheet parts, stamping, bending, argue, stereotypes model, stretching, pressing of materials of plasticity, such as punching, bending, flanging thin stretch assignments, may also perform calibration, pressure equipment, plastic products and powder products molding operation.  It is also called universal hydraulic press because of its wide range of applications.  

• Advantages of forming technology

Compared with the traditional stamping process, hydroforming process has obvious technical and economic advantages in reducing weight, reducing the number of parts and molds, improving stiffness and strength, reducing production costs and so on. It has been applied more and more in the industrial field, especially in the automobile industry.

In the automotive industry, aviation, aerospace and other fields, reducing structural mass to save energy in operation is a long-term pursuit of people's goal, is also one of the trends of the development of advanced manufacturing technology.  Hydroforming is an advanced manufacturing technology for lightweight structure.  

Hydroforming is also known as "internal high pressure forming", its basic principle is to take the tube as the blank, in the tube inside the application of ultra-high pressure liquid, at the same time, the two ends of the tube blank exert axial thrust, feeding.  Under the joint action of two kinds of external forces, the tube material is plastic deformed, and finally fits with the inner wall of the mold cavity, and the shape and precision of the hollow parts meet the technical requirements.  

For hollow variable section structural parts, the traditional manufacturing process is to stamping forming two half pieces first, and then welding into a whole, while hydroforming can be formed as a whole along the section of the hollow structure changes.  Compared with stamping welding process, hydroforming technology and process have the following main advantages:  

1. Reduce quality and save materials.  For automobile engine bracket, radiator bracket and other typical parts, hydroforming parts can reduce 20% ~ 40% than stamping parts;  For hollow step shaft parts, the weight can be reduced by 40% ~ 50%.  

2.  Reduce the number of parts and molds and reduce the cost of molds.  Hydroforming parts usually only need one set of die, and stamping parts mostly need more than one set of die.  The number of hydroforming engine bracket parts was reduced from 6 to 1, and the number of radiator bracket parts was reduced from 17 to 10.  

3. It can reduce the welding amount of subsequent machining and assembly.  Taking the radiator bracket as an example, the cooling area increased by 43%, the number of solder joints decreased from 174 to 20, the number of processes decreased from 13 to 6, and the productivity increased by 66%.  

4. Improve the strength and stiffness, especially the fatigue strength, such as the radiator support of hydroforming, its stiffness can be increased by 39% in the vertical direction, and 50% in the horizontal direction.  

5. Reduce production costs.  According to the statistical analysis of the applied hydroforming parts, the production cost of hydroforming parts is reduced by 15% ~ 20% on average compared with stamping parts, and the mold cost is reduced by 20% ~ 30%.