| Sheet metal hydroforming is advanced technology and is developed and applied in recent years. Sheet metal hydroforming has characters such as low die cost, short manufacturing cycle and high form limit. The parts processed by it have high precision and good surface quality compared with traditional technology, so it is suit to process sheet parts with complex shape and high precision.Sheet metal hydroforming in pairs is new technology that is developed on base of single sheet metal hydroforming. It not only has the advantages of hydroforming but also increases the efficiency and cuts down devices, so the processing cost is reduced. Sheet metal hydroforming in pairs is suit to process the container such as motorbike tank that is made by welding upper cover and lower cover.Advanced equipment is the basis of advanced process. Though special equipment for hydroforming has been produced, the price of it is very expensive which exceeds purchasing power of domestic factory.Aim at these situation,this paper introduces the scheme to transform general hydraulic press to a new press which can be suit for sheet metal hydroforming in pairs on the base of YH28-100/180-SM hydraulic press in the lab and priority researchs the control system of it. First, this paper introduces the principle of YH28-100/180-SM hydraulic press, the die of sheet metal hydroforming in pairs, sealing, hydraulic system of forming force and VBHF. Secondly, this paper introduces the modification of hydraulic system and control system which can realize the processing parameter of hydroforming. Last, this paper researches the control algorithm of forming force and BHF, and analyses it by Matlab, the result indicates the self-tunning fuzzy PID can impove nature of control system of hydroforming effectively. |
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