The pull current Cheng of Die Casting mould and technical principle
- source:XIMENG CNC Machining
The fundamental of machine of Die Casting of hot pressing room: Of machine of Die Casting of hot pressing room pressure room the metallic fluid of immerge crucible is normally medium, die Casting machine perhaps compresses air to produce pressure to push dynamic pressure to shoot drift to move with lever orgnaization. In Die Casting process, metallic fluid is in pressure when shooting drift to rise, press through importing You Rong to change crucible to enter room; Pressure shoot drift when next pressing, metallic fluid fills up along channel classics nozzle antrum of Die Casting model; Wait for refrigeration caky after shaping, can open a model to take out Die Casting, finish loop of a Die Casting. 2.
Cold the fundamental that controls machine of room Die Casting is cold those who control machine of room Die Casting pressing room and fused crucible is departure, when Die Casting, need is changed by frit fill inside crucible take metallic fluid to be irrigated press Die Casting of travel of the reentry after the room. According to Die Casting model and control the relative position of the room, cold press machine of room Die Casting to be able to be divided for vertical, horizontal, complete vertical 3 kinds of type. A.
Vertical is cold it is perpendicular that the fundamental that controls machine of room Die Casting controls the central route of the room, in Die Casting process, irrigate press the metallic fluid in the room to fill to expect drift is held in the palm instead, press to make metallic fluid is in before shooting, do not send enter a model inside, before assuring to expect drift is beginning pressurization instead, stem the runner hole that runner covers, use spring normally or be control of a powerful person of hydraulic pressure control, will expect drift supports the height that asks in place instead; Pressure shoot drift when next to metallic fluid face pressing, expect drift begins to drop instead, fall into cone-shaped aperture inside, opened runner hole at this moment, metallic fluid is pressed into mould antrum; Protect after pressing condensation, pressure shoot drift to pick up, expect drift rises instead at the same time, cut off more than makings and give its tip pressure room; After this opens a model to take out cast (expect drift already returned original position instead) , complete cycle of an excessive casting. B.
Horizontal is cold the fundamental that controls machine of room Die Casting controls the central route of the room is a level. In Die Casting process, metallic fluid is passed pouring aperture is irrigated press pressure room; Pressure shoot drift to be advanced ahead, control runner of metallic fluid classics mould speech; Protect the model flies after pressing condensation, more than makings and Die Casting take out together, complete cycle of a Die Casting. C.
Complete vertical is cold it is perpendicular that the fundamental that controls machine of room Die Casting controls the central route of the room. It is divided again shoot to press press on drift type and pressure shoot type is pressed below drift. The Die Casting process that type controls on and horizontal are cold control appearance of machine of room Die Casting similar; And pressure shoot the Die Casting process that type controls below drift and vertical cold pressure photograph of machine of room Die Casting is similar. 3.
The flow condition of fluid of the metal in Die Casting process and its flow are characteristic: Fluid of the metal in Die Casting process fills up below high-pressured high speed the time of mould antrum is extremely short, it is a few seconds only commonly. First phase is complete eject, after this is inside extremely short time, one party is faced model antrum each place fills up, wear in very complex variation on one hand, till be full of model till antrum. The flow condition that meets metallic fluid correctly reachs his to change, master a metal to fill up the rule of configuration makes full use of this kind of character of metallic fluid, it is proper design gating system, die Casting gives a of good cast critical factor. 4.
The sort that metal of the liquid state when filling up sheds reachs his to use characteristicly: The flow condition of fluid of the metal in wanting to observe Die Casting and its flow are characteristic, not be an easy thing, worker of domestic and international Die Casting fills up to the metal configuration also has offerred all sorts of different point of views. The metallic fluid that is informed with respect to the place in the experiment now fills up condition, summarize as follows: 1.
Eject and machine of gush efflux Die Casting are in normally enter metallic hydraulic pressure below Die Casting condition inside antrum of general Die Casting model, in first phase, through inside the metallic fluid after runner is carrying the action of kinetic energy falls, resemble cartridge with very high rate euqally forward and point-blank. Its direction depends on inside the direction of runner, the metal of this kind of condition flows call " eject " . The metallic fluid of high speed eject jointly with model antrum wall and model core or it is other metal flows to collide, right now, the change of energy of one part motion inside metallic fluid is heat energy and pressure, and changing metallic fluid velocity of flow and ongoing way while, along model antrum wall flows. The character that because the rest carries kinetic energy makes metallic fluid edge sharp,advances still stronger, because the metal of this phase flows with general pressure current quality (from pressure high one side flows to the one side with low pressure) differ somewhat, say for " eject flows " . Eject and gush efflux have an apparent character, can advance point-blank below the effect that measures in very big carry kinetic energy namely. It is OK to use this kind of character preferential the place that fills up the place letter with those greater resistance does not have air discharge duct, and these place rely on pressure current fill up hard. 2.
Pressure current reachs his to use only eject and gush efflux, return enough to make metallic fluid fills up whole model antrum, below most circumstance, eject and eject shed a retentive motion energy to had be notted fill in metallic fluid go to full when, because be in model happen inside antrum collide, attrition uses up almost with aeriform obstruction to use up. Accordingly, should make fill up the metal flows " hind flow " part (the share that metallic fluid reachs finally) metallic fluid, in follow-up metal fluid drive next advancement, the metal of this phase flows call " pressure current " . The channel part that pressure current produces in deviate eject and gush efflux commonly and be far from inside the place of runner. The character with ongoing on the channel with little resistance pressure current is very strong. In the place that pressure current place fills up, if pressure current is divided into a few affluent, criterion metallic obstruction is dispersive; Be like the insular state position with occurrence larger obstruction, metallic fluid can be only all round its flow, and cannot fill up the place of block muscularity. The main factor that creates force of metallic flow resistance is Die Casting bad distribution, metal flows curve motion, model the surface roughness of antrum surface is tall, model there is aeriform pressure to wait a moment inside antrum. Pressure current sheds big in that way motion energy without eject, but the pressure that it has the supply in accepting follow-up metal fluid however can, what make the metal advances along wall thereby is characteristic. Use this kind of character, can very conveniently model effectively eduction goes to the gas inside antrum, in the place that pressure current fills up, the assemble is worn fill up by eject and gush efflux place partial gas, because this is in,this place must open air discharge duct. 3.
Again the part that eject phenomenon greatens suddenly in the channel of pressure current or gush efflux (Bao Bi arrives the metabolic place of large wall) , metallic fluid leaves again model antrum wall forms eject state, condition of this kind of eject says for " again eject " . Happen again the place of eject produces air hole and shrinkage cavity very easily, inside reason antrum with happening again eject is the idealest. Because this is designing Die Casting with Die Casting should avoid as far as possible when the model again the happening of eject phenomenon, but often avoid hard actually, should use for this above all to happen again the place of eject fills up of metallic fluid inside runner plan, adopt at the same time rise fill shrink the method of metallic shedding effect, inside it is advisable that runner is set in the place that stands by cast large wall. 4.
Fill shrink the temperature of fluid of metallic shedding metal falls you can produce systole, when metallic fluid thermal drop is small, its surface and internal temperature do not drop at the same time. The temperature of layer of metallic fluid surface drops lickety-split, subsequently internal temperature also drops accordingly. From this knowable, metallic fluid begins to cool from the surface first caky, in-house a little lag is caky and contractive. The process is here medium, if do not complement to its interior,the metal can produce shrinkage cavity, fill shrink the metal flows even if inside the metallic fluid of runner place has not cool caky before, increase the pressure with indoor high pressure instantly, to model metallic fluid complements inside antrum. Ideal Die Casting, should be in the metal fluid fills up end all and caky before be over, undertake pressurization fills instantly shrink, fill shrink the time with metallic effective shedding is longer, criterion Die Casting quality is better. This one idea is in theoretic it is feasible, although mould temperature undertakes Die Casting below the case that has gradient, try to let fill up namely the metallic fluid of cease, first from be far from inside runner place begins caky in, next in order ground is inward runner direction is caky, runner is in inside caky finally. CNC Milling CNC Machining