1. From the basic point of view four-column hydraulic press and single-column hydraulic press are hydraulic press, only its use is different. So when buying and selling, according to their own workpiece shape and process needs, combined with the characteristics of various body structure, choose the right model, can reduce unnecessary cost expenditure, more conducive to the work accuracy and efficiency, so the choice of stereotypes is particularly important.
1.1 Application industries
1.1.1 Four-column hydraulic press: It is mostly used for stamping, flanging or cold extrusion of various metals, and can also stop pressing metal powder and stop pressing various non-metallic materials, and is also commonly used in the automobile repair industry and motor industry.
1.1.2 Single-column hydraulic presses: also known as single-arm hydraulic presses. It is mainly used to calibrate all kinds of shafts and other parts and to press some electrical parts, but also for the pressing of non-metallic materials and the stretching of small parts, embossing and other operations. It can be operated by hand or foot, and the pressure can be adjusted in a wide range to stop at will.
1.2 Structural differences
1.2.1 Four-column hydraulic press: mainly relying on PLC or button centralized control to complete semi-automatic consumption, and its machine pressure and speed can stop within a large range of stroke independent adjustment, but also to complete the fixed pressure forming and fixed-range forming, and has the function of holding pressure and automatic return
1.2.2 Single-column hydraulic presses: mainly operated by a handle or foot pedal, and also able to adjust the pressure and control the size of the stroke in a wide range.
2. After determining the required cylinder working pressure tonnage size, to see the several technical indicators and parameters we must pay attention to.
2.1.1 The advantages of the four-column hydraulic press process a wide range of applications, such as powder molding, injection molding process, metal stretching rolled edge, etc., the body is evenly stressed, the work of the force slider no obvious deformation and lifting phenomenon, simple structure, economical. Disadvantages of a large footprint, high requirements for production and processing assembly.
2.1.2 opening size, the large opening size is the cylinder return to the end, the distance between the lower plane of the slider and the surface plane of the table, the large opening size minus the cylinder stroke is the small opening size.
2.1.3 Cylinder stroke, the length of the cylinder stroke directly determines the size of the large opening and the small opening of the machine.
2.1.4 The working speed of the cylinder, the speed of the cylinder is directly related to the efficiency and process requirements, the working speed of the cylinder can be divided into fast down speed, slow down speed and return speed of the ram.
2.1.5 The height of the working table from the ground, the height of the working table from the ground is generally no special circumstances to 700 to 750 applications.
2.1.6 Some special process requirements also include the lower top cylinder, the size and stroke of the lower top cylinder, the size and stroke of the push-pull cylinder, the special process of the cylinder work to keep pressure delay return, pressure accuracy, position accuracy, etc.
2.2 The advantages of the single column hydraulic press are relatively simple production and short processing cycle, the integrated structure covers an area of small, the length of the table is not limited, the disadvantage is that due to the structure, the body is not well made, the material is not solid, it will lead to the body lifting head deformation is obvious, and the front and rear size of the workpiece is limited.
2.2.1 Throat depth, throat depth refers to the distance from the centre of the cylinder head to the chest plate of the machine, this parameter directly determines the size of the diameter of the workpiece, for example, if the throat depth is 250MM, then the maximum pressing diameter of the machine is 500MM.
2.2.2 Opening size, * The large opening size refers to the distance from the lower plane of the indenter to the surface plane of the table after the cylinder has returned to the bottom. For example, if the workpiece axis is 400MM long, then the maximum opening of the machine should be larger than 400MM.
2.2.3 Cylinder stroke, the length of the cylinder stroke directly determines the size of the large opening and the small opening of the machine.
2.2.4 The working speed of the cylinder is directly related to the work efficiency and process requirements, but in straightening, levelling and precision pressing, the working speed of the cylinder should not be too fast, as the fast speed of an ordinary press will cause the position accuracy to be difficult to control, thus leading to over-pressing.
2.2.5 The size of the working table and the height of the table from the ground, and whether or not the table needs a drop hole, should be chosen according to your needs before purchasing.