The cold press frame is mainly composed of four parts: the upper roof, column, pressing plate, and the lower floor of the lower floor mainly play a bearing role. The pressing plate bearing the pressure from the pressing plate is mainly used to transfer the pressure of the hydraulic cylinder, so that the pressure can be evenly distributed to the upper roof and the vertical column of the plywood. The main role of the pressing plate is to bear the reverse force. In addition, the column also plays a supporting mechanism role. The combination of the frame adopts the form of welding. The pressure part of the whole machine adopts the 30mm thick Q235 plate, and the height of the weld is more than 15m.
Preliminary analysis of the plywood cold press frame shows that the frame can be cast or welded. Let's analyze which method should be selected for this mechanism.
1. Casting is a method of pouring liquid metal into a mold suitable for the shape and size of a part and obtaining a blank or a part after it is cooled and solidified. The casting is most suitable for the forming of blanks or parts with complex shape, especially with complex inner cavity. It is also suitable for mass production. The internal structure of the casting is loose, the grains are coarse and easy to produce shrinkage cavity, shrinkage cavity, porosity and sand hole. The mechanical properties are low, the quality is not stable, the casting working environment is poor, and the labor intensity is large.
2. Welding is a kind of connection formed by the combination of atoms or molecules between two or more metal parts by means of heating and sometimes pressurizing. The welding structure has the advantages of high strength and rigidity, light weight, good sealing performance, low cost, short production cycle, good reliability and simple construction.
For the comparison of the above two points, we can see that what we want to do is a 200t press. If we choose to cast, the possible cost will be very high, because we need to make the mold and other work, and the cycle is long. If we choose to weld, the strength and rigidity meet the requirements, and the structure is light, the sealing is good, the cost is low, the production cycle is short, the reliability is good, and the construction is simple.
That is to say, we should choose the welding form and adopt the form of joint action of two hydraulic cylinders in the design to avoid load concentration, increase the tonnage of pressure and expand the working pressure range of the machine.
In terms of materials, we choose ordinary carbon structural steel Q235, because Q235 has good welding performance and strength: in order to increase the strength of the machine body, the pressure part of the whole machine is all made of 30mm thick Q235 plate, and its welding method is multi-layer and multi pass welding, and the weld height is not less than 15m. We can make the structural strength high by using this method, And the structure is also simple in weight: because the frame includes upper and lower plates and pressing plates, which are all welded with steel plates, while the column is welded with channel steel and steel plates, so the middle is hollow, which greatly reduces the weight of the fuselage. Compared with the same specification cast, its weight is greatly reduced. Therefore, conclusion: Q235 steel plate assembly welding structure should be selected.