Comparison of advantages and disadvantages of hydraulic press and mechanical press

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 processes and press forming processes, such as: forging, stamping, cold extrusion, straightening, bending, flanging, sheet deep drawing, powder metallurgy, pressing and so on. So who is better than a hydraulic press or a mechanical press? Let's compare the difference between the two:

The hydraulic press is a universal press with an exquisite structure. It has a wide range of uses and high production efficiency. The hydraulic press is relatively stable in loading. It can be widely used in cutting, punching, blanking, bending, deep drawing, shaping, riveting and forming. By applying strong pressure to the metal blank, the metal is plastically deformed and fractured to be processed into parts. The mechanical press has greater impact and is more suitable for blanking, cutting and other separation processes.

The hydraulic press is the pressurized liquid produced by the hydraulic pump to transmit power through the hydraulic actuator of the control circuit. The liquid meson has water, emulsion, and hydraulic oil. It is characterized by high working pressure, stable operation, free control of the working stroke, large adjustment range, large working space, moderate working efficiency, and can complete most of the work of mechanical presses, and has a wide range of applications. The configuration of hydraulic press is more complicated. A slightly larger press is generally equipped with an independent pump station, the control part and circuit are more complicated, and the cost is relatively high.

Mechanical press machines are divided into two types: crank type (punch) and screw type (friction press, cool press). The crank sahft type press transfers force by the crankshaft, and it is characterized by fast running speed, high working efficiency, fixed working stroke and non-adjustable working stroke, and overload operation is strictly prohibited. Generally used for blanking, punching, stretch forming, etc.

The friction press uses the wheel to drive the friction wheel to transmit force by inertial rotation of the screw. The characteristic is that it is not restricted in the effective working range of the screw, the transmission pressure is large, and the work efficiency is moderate. Operation is not easy to control. Generally used for material correction; simple molding; die-casting cavity molding, etc. 

The cool press is mainly used for stretching and forming work. It relies on the screw to directly transmit force. 

Mechanical press features 1) fast operation, high efficiency, low cost, relatively simple control part, easy to maintain, 2) small working table, in order to increase its transmission power is generally equipped with a large counterweight wheel (flywheel), when running The noise is large and the vibration is large.

Other differences:

1. The mechanical press is fast, but not as powerful as the hydraulic press. The hydraulic pressure is high but the speed is slow.

2. Compared with mechanical transmission, hydraulic transmission has a large power/mass ratio, which is convenient for stepless speed regulation and overload protection, flexible and convenient layout, and other technical advantages

3. From the perspective of molds, hydraulic presses are suitable for large, complex and precise automotive sheet metal parts, especially with the "stretching" function. Suitable for large covering parts of automobiles, door parts, etc. Compared with the mechanical press, its characteristics are indeed compact, and the product structure and size stability are better. Maintenance is more convenient than mechanical presses, because of the standardization of hydraulic parts and the maturity of the theory is very high. For example, to find faults, you can find the wings from a hydraulic schematic diagram. Just insist on using genuine hydraulic oil. The efficiency issue is two issues, which are incomparable.

4. Mechanical presses generally rely on impulse, and the pressure stroke is generally about 5 mm. The hydraulic machine has endurance, and the pressure stroke is the same as the cylinder stroke.

5. The mechanical efficiency is high, the speed is fast, the pressure generated is small, and the overload is easy to cause accidents. Generally thin parts. The hydraulic press is the opposite.

6. The mechanical press has high efficiency, but the vibration and noise are large; the hydraulic press solves the problem of reducing vibration and noise, but the efficiency is low.

7. The mechanical force is usually smaller. Some of the machinery is inertial speed and impulse; the hydraulic press is pressurized by the pump.