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Die Casting Machine_4

Tham khảo tài liệu 'die casting machine_4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Simpo PDF Merge and Split Unregistered Version - http www.simpopdf.com Section 7.3. The validity of the common diagram D1 Figure 7.7 pressure at the plunger tip Pl the flow rate Q and the gate velocity u3 as a function of plunger diameter Al trends are realistic. Gate area variation Energy conservation power supply machine characteristic Let s assume that mass conservation is fulfilled and hence the plunger velocity can approach infinity Ui 00 when Di - 0 under constant Qmax - The hydraulic piston also has to move with the same velocity Ui- Yet according to the machine characteristic the driving pressure approaches zero Fbi Pỉí2 0. Therefore the energy supply to the system is approaching zero. Yet energy obtained from the system is infinite since jet is inject in infinite velocity and finite flow rate. This cannot exist in our world or perhaps one can proof the opposite. Energy conservation power supply Assuming that the mass balance requirement is obtained the pressure at plunger tip Fl and gate velocity Ư3 increase and can reach infinity when Fl 00 then u3 - oo when the plunger diameter is reduced. Therefore the energy supply to the system has to be infinity assuming a constant energy dissipation actually the dissipation increases with plunger diameter in most ranges However the energy supply to to make a question in regards the system c.v. only the liquid metal system would be PbiAbiUi finite amount and the d ss pa d bc y energy the system provide plus would be infinity infinite gate velocity plus dissipation. Energy conservation dissipation problem A different way to look at this situation is check what happen to physical quantities. For example the resistance to the liquid metal flow increases when the gate velocity velocity is increased. As smaller the plunger diameter the 77 What have your membership dues done for you today plagiarise copyright 2000 by Dr. Bar-Meir Simpo PDF Merge and Split Unregistered Version - http www.simpopdf.com Chapter . pQ2 Diagram .