MITSUBISHI HEAVY INDUSTRIES PLASTIC TECHNOLOGY CO., LTD.

We developed an electric injection molding machine that is a space-saving ultra large-sized machine "3000em" with the world's largest mold clamping force of 3,000 tons. Introduced into the market from the Dec. 9th. This is a cutting edge next-generation model machine that exhibits power in the molding of large automobile parts such as bumpers and realizes an originally developed new model center press platen^*1and molding of difficult to reach burrs through the use of electric mold under inside-mold pressure waveform control^*2 and also contributes to greater efficiency of production and reductions in cost. This machine realized an installation space almost identical to our hydraulic MMIII series, which is the world's smallest space in the comparable class. Our objective is to fix our sights on the marketplace of injection molding machines for the automotive industry as a global standard machine and to develop active business in Japan and overseas.

Electric injection molding machine with mold clamping force of 3,000 tons
"3000em"

The mold clamping force of 3,000 tons is realized by installing a high torque, low RPM high capacity DD servo motor originally developed by Mitsubishi. The marketplace of this class is centered on molding of large automobile parts. The "3000em" far superior to electric injection molding machines until now, with a maximum 1,800-ton class mold clamping force. In addition to the "3000em" being equipped with new devices such as an electric mold opening / closing and electric mechanical split nut opening / closing system^*3 and a UB screw with an MD melter for automobile parts^*4, it achieves 30% shorter as the world's fastest cycle time compared with a conventional hydraulic machine in the production of automobile bumpers.

The greatest feature of the "3000em" is the fact that it eliminated burr defects of molded parts and achieved stable quality. The new type divided center press platen that makes possible molding without burrs ensures uniform of mold parting surfaces by using an original center press construction. Furthermore, the simultaneously developed electric mold under inside-mold pressure waveform control performs 4-axis synchronized control of a high-capacity DD servo motor installed in an injection axis drive to maintain the melted resin pressure inside the mold at a low pressure and exhibits its effects in preventing burrs.

We used our original two-platen mold clamping mechanism^*5 and hybrid power system^*6 to achieve energy saving and space saving. From the standpoint of energy saving, the power consumption is 60% reduced compared with hydraulic machine. And from the standpoint, the machine length is approximately 15 m, which is 80% of the same class toggle type clamping mechanism. Furthermore, less noise around the machine is realized with the use of a low noise echo pump system^*7 and a DD servo motor for injection. This improves the working environment.

An important topic of the molding of large automobile parts as represented by bumpers is high cycles and thinner walls. The current "3000em" is equipped with functions such as high-speed injection (such as a high capacity DD servo motor), high-speed mold opening / closing (electric mold opening / closing and electric mechanical split nut opening / closing system), and high-speed plasticization (electric high-speed screw rotation mechanism) to handle higher speeds. The "3000em" can also maintain power to spare for thinner walls with the use of multi-point gate filler (sequential gate control)^*8. Initial machines are expected to be shipped March 2005, and we will then continue to focus on the target of large automobile parts, such as bumpers, and actively promote sales directed towards related industries.