摘要:
A mechanical apparatus and method for the casting of metal components is disclosed. The apparatus includes a gooseneck having dual plungers for drawing molten metal from a crucible of hot metal and for forcing the drawn molten metal through the system, a hot runner assembly having a thermal valve developed in time and positioned adjacent the mold cavity, and a machine nozzle positioned between the gooseneck and the hot runner assembly. The dual plunger is fitted with a shot plunger and a shutoff plunger which work in conjunction to allow for molten metal to be drawn into the gooseneck but to stop its passage into the gooseneck when the metal is forced through the system into the die. Both temperature and flow rate are carefully monitored and controlled. Two embodiments of the gooseneck are provided in which the positions of the shot plunger and the shutoff plunger are altered and in which the molten metal is drawn into the gooseneck at different locations.
摘要:
A method and apparatus for the casting of metal components is disclosed. The apparatus includes a plunger for drawing molten metal from a crucible of hot metal and for forcing the drawn molten metal through the system, a hot runner assembly having a nozzle tip positioned adjacent the mold cavity, and a machine nozzle disposed between the plunger and the hot runner assembly. An adaptive and universal hot runner manifold having removable hot runner injectors fitted thereto is provided for use with a variety of castings.
摘要:
A method and apparatus for the casting of metal components is disclosed. The apparatus includes a gooseneck for drawing molten metal from a crucible of hot metal and for forcing the drawn molten metal through the system, a hot runner assembly having a hot runner tip positioned adjacent the mold cavity, and a machine nozzle inserted between the gooseneck and the hot runner assembly. The gooseneck is fitted with a one-way check valve to allow for molten metal to be drawn into the plunger but to stop its passage out of the gooseneck when the metal is forced through the system into the die. A thermal valve is formed within the hot runner tip to provide a metal blockage from the molten metal which prevents the back-flow of molten metal back into the hot runner assembly. Both temperature and flow rate are carefully monitored and controlled.
摘要:
A method and apparatus for the casting of metal components is disclosed. The apparatus includes a gooseneck for drawing molten metal from a crucible of hot metal and for forcing the drawn molten metal through the system, a hot runner assembly having a hot runner tip positioned adjacent the mold cavity, and a machine nozzle inserted between the gooseneck and the hot runner assembly. The gooseneck is fitted with a one-way check valve to allow for molten metal to be drawn into the plunger but to stop its passage out of the gooseneck when the metal is forced through the system into the die. A thermal valve is formed within the hot runner tip to provide a metal blockage from the molten metal which prevents the back-flow of molten metal back into the hot runner assembly. Both temperature and flow rate are carefully monitored and controlled.
摘要:
A method and apparatus for the casting of metal components is disclosed. The apparatus includes a plunger for drawing molten metal from a crucible of hot metal and for forcing the drawn molten metal through the system, a hot runner assembly having a nozzle tip positioned adjacent the mold cavity, and a machine nozzle disposed between the plunger and the hot runner assembly. An adaptive and universal hot runner manifold having removable hot runner injectors fitted thereto is provided for use with a variety of castings.
摘要:
Methods for improving the performance of VLSI layouts designed by a timing driven physical design tool. According to one embodiment of the present invention cells of a circuit design are placed in a placement of an integrated circuit, and wires are routed between the cells to complete a layout of the integrated circuit having a number of nets. The placement is analyzed for timing performance, and an improved location is identified for each cell in the placement. The improved location is identified based on an estimated savings in delays caused by all of the nets in the layout to a signal propagating through the layout when the cell is placed in the improved location and a net criticality of each net in the layout.
摘要:
A computer implemented method for simulating a resistive circuit, including a plurality of macro circuits that are arranged hierarchically. The method includes the steps of reading a netlist description of the resistive circuit and recursively traversing the resistive circuit starting from terminal nodes of a macro circuit at a highest level of hierarchy using precharacterizations of each of the plurality of macro circuits to determine node voltages and branch currents of the resistive circuit.
摘要:
In a first variation, a thermally aware design automation suite integrates system-level thermal awareness into design of semiconductor chips, performing fine-grain thermal simulations of the chips based on thermal models and boundary conditions. The suite uses results of the simulations to modify thermally significant structures to achieve desired thermal variations across a chip, meet design assertions on selected portions of the chip, and verify overall performance and reliability of the chip over designated operating ranges and manufacturing variations. In a second variation, a discretization approach models chip temperature distributions using heuristics to adaptively grid space in three dimensions. Adaptive and locally variable grid spacing techniques are used to efficiently and accurately converge for steady state and/or transient temperature solutions. The modeling optionally reads a mesh initialization file specifying selected aspects and parameters associated with controlling use and behavior of the variable grid spacing techniques.
摘要:
A method and apparatus for simulating a microelectronic circuit or system includes the storing of a microelectronic circuit or system representation in a computer and then transforming the representation into an equivalent DC circuit containing resistive, capacitive and inductive elements. Then, a directed graph of the DC equivalent circuit is generated and a spanning tree is constructed therefrom. The spanning tree is then actually or virtually traversed to obtain multiple generations of circuit moments. The moments are then used to calculate the poles and residues for a given node and generate an approximate model of the circuit's transient response at that node. Moment shifting is used to provide for a stable approximate model. The actual residues corresponding to the coefficients of the time domain representation for the model can be calculated using the first q-1 moments. This constitutes a partial-Pade approximation.
摘要:
In a first variation, a thermally aware design automation suite integrates system-level thermal awareness into design of semiconductor chips, performing fine-grain thermal simulations of the chips based on thermal models and boundary conditions. The suite uses results of the simulations to modify thermally significant structures to achieve desired thermal variations across a chip, meet design assertions on selected portions of the chip, and verify overall performance and reliability of the chip over designated operating ranges and manufacturing variations. In a second variation, a discretization approach models chip temperature distributions using heuristics to adaptively grid space in three dimensions. Adaptive and locally variable grid spacing techniques are used to efficiently and accurately converge for steady state and/or transient temperature solutions. The modeling optionally reads a mesh initialization file specifying selected aspects and parameters associated with controlling use and behavior of the variable grid spacing techniques.