Disappear conveyer of scraper of modular whole casting is mid the control of groovy stoma blemish

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[summary] air hole is to disappear modular whole casting is mid the flaw with common chamfer, appear below cell body upside or blind angle skin, blame close reach when closing partly, can undertake solder fills, deep cell body is caused to discard as useless when closing. Scraper conveyer is colliery put together collects the facility for transporting with necessary working face, it is the key that the coal that select an area carries. Application disappears modular whole casts mid chamfer, its quality key is the generation that controls stomatic blemish. We pass long-term quality management, mastered the mechanism of stomatic generation and control method. One, because mid chamfer body is special,stomatic blemish produces mechanism, following plan institute are shown, each model dimension sees next tables. Air hole is located in cell body upside more or the skin of complex part falls, air hole exists alone sometimes, sometimes poriferous coexist, hole wall darkly is lubricious. Classics analysis, the account that produces air hole is as follows: (Aerification of about of 1) cell body is decomposed generate many gas and hangover cannot seasonable eduction casting mould, it is the main source that forms stomatic blemish. (2) because gating system design is unreasonable, metallic fluid is filled model speed is unsuited, cause fill model forward position wraps aerification hangover nip to be in metallic fluid, again aerification forms air hole. (The permeability of coating of 3) casting mould is low, model the gas inside antrum and hangover cannot eliminate in time, in fill model air hole is formed below pressure action. (4) is pouring temperature is low, fill model fluid of forward position metal cannot make about fills minute of aerification, not aerification decomposes hangover to have not enough time float collect is caky to rising head air hole is formed in casting mould. (Design of position of the runner inside 5) is unreasonable, fill model when form blind angle division, as a result of model action of counterpressure of the gas inside antrum, make gas and hangover accumulative in cell body complex part forms air hole. (6) is pouring unreasonable generation judges career stream, shine stream, air of be involved in and make air hole. (Volume of 7) runner cup is too minor, metallic fluid forms eddy current to invade air and make air hole. (Permeability of 8) molding sand is bad, cause false negative pressure to spend, make rate of air sucked in required is less than gas evolution, aerification content cannot be smoked in time to leave model antrum, form air hole or elephant skin thereby. 2, the method that controls stomatic blemish 1. Choose appropriate about data to use the expanded plastics with low density, high strenth and small gas evolution to make appearance, those who choose 18 ~ 22kg/m3 is small bead bead adds the EPS that has aerification accelerant or EPMMA copolymerization expanded plastics, the requirement achieves 50 ~ 55kPa in the intensity after coating is dry, aerification is complete, hangover is little, without harm, easy treatment. 2. The form of a flight of stairs that cell body of reasonable design gating system uses the runner that do not have a horizontal stroke gating system, setting of cell body coping fills shrink, the dark rising head of an organic whole of collect broken bits, use balanced and caky technology and perimeter commercial law to make rising head is achieved fill shrink, the function of collect broken bits, order of implementation cell body is caky, avoid stomatic generation. 3. The permeability coating that raises casting mould coating is fireproof aggregate granuality should appropriate, use agent of compound in suspension to reach fight high temperature binder. Make up coating to have high temperature intensity to reach wear away stiffness is good, yi Gan dry, yi Tu is brushed, exhaust ability is great, permeability is good, agglomeration is even, easy fall off, as not wet as molding sand embellish. Ply of cell body coating is 1.

2 ~ 1.

5mm, breathe freely rate for 0.

415m4/Pa · Min, exhaust ability is 2.

172m3/s. The quality management of cell body coating is very crucial, because coating has quite great adherent strength, pouring when coating layer won't by interior of fluid of metal of be involved in, can adhere to thoroughly in cast appearance, when cast refrigeration comes off automatically to the coating when critical temperature cast. In mass-produced when should detect regularly coating permeability, adjust coating composition in time, eligible cast is to rely on optimal coating to assure, because this controls coating quality,not allow to ignore. 4. Control is appropriate pouring about of temperature cell body is in pouring fill model in the process, the hot action of metallic fluid suffers pouring of temperature restrict. When pouring when temperature is high, metallic fluid hot action is sufficient, the child heating up solution of about is gaseous state, it is easy to eliminate below the action of negative pressure field; When pouring when temperature is low, metallic fluid hot action is inadequate, the child heating up solution of about is liquid state, can jam coating layer air gap, the child that heat up solution eliminates suffocate suffocate, model counterpressure is formed inside antrum, fill model fluidity drops accordingly, generate stomatic odds very tall. Carry out a proof, of cell body pouring temperature summer is controlled for 1580 ℃ , winter is 1620 ℃ left and right sides. 5. Reasonable pouring of positional cell body optimal and pouring all surfaces that the position is body are filled up cheek by jowl by molding sand, pouring when obtain good aerification condition, facilitating exhaust, divide broken bits. The choice is pouring positional principle is: The face of the largest size should be in about perpendicular or tilt, stand that is to say irrigate or inclined irrigate. Because about itself is airtight, fill model when the gas that about heat separates generation and hangover must from about and fill model the clearance flank eduction between metallic fluid face, the side watch area that passes eduction is jumped over greatly more advantageous, namely the principle with the largest area of alleged side watch. When pouring after the position is firm, whether casting gives eligible cast, depend on inside of runner introduce the seat. Affirmatory inside the principle of runner position is: Fill model successful, rise equably, without blind angle, aerification is sufficient. Inside the appearance of runner should make it opens type, length is appropriate, do not produce splash, eliminate thereby cold lie between, prevent stomatic generation. 6. Reasonable pouring what speed and negative pressure spend cell body is pouring craft is with the metal fluid fills runner cup, close straight runner is criterion. If too fast or infuse rate is too slow, can make fill model the process causes intense and disorder intercurrent unripe acuteness boiling, will have not enough time the nip of about body bag of aerification is caky in metallic current form air hole. Ideal pouring speed is to give casting mould inside model, fluid displacement offers enough metallic fluid, make metallic fluid is filled model speed is equal to about aerification speed. Craft point is as follows: (1) straight runner is made hollow prevent splash when be being irrigated first, splash instead happen, straight runner is made hollow. Use first small shed metallic fluid dot to connect straight runner to flow to be full of runner cup to close quickly greatly again straight runner, maintain vacuum to spend, when sinking no longer till fluid of runner cup metal till. (2) notes aperture to adjust limitation with runner cup pouring the speed practice through ten years, we think to disappear the gating system form with modular appropriate craft is enclosed, to preventing air hole generation has better effect. Be in namely pouring fill model inside time, the metallic juice that gating system place provides and stall of about aerification disappear spend synchronism to be enclosed gating system. Be in pouring when temperature is constant, the aerification disappear stall of about spends the absorption of heat with about to concern, it is same that the stall of about aerification disappear with identical density, identical large wall is spent. Because cell body structure, wall is large evener, about absorption of heat is basic it is consistent, the size ration that so my company notes hole with runner cup is offerred fill model metallic fluid, fill aptly in order to obtain model speed. Pouring when metallic fluid fills runner cup all the time, nothing more than excessive, splatter destroy close filmy, assure field of balanced negative pressure, make the close fact of molding sand is spent be more than the molding sand shears to casting mould force, do not collapse box, ;burst;ulcerate;fester model. (3) is pouring must not break in the process flow and shine stream pouring do not allow to flow in the process, shine stream happen, once straight runner is bare,be in air, below negative pressure action air is entered model antrum forms stomatic blemish, make cast makes waste product. (4) decides reasonable vacuum spends appropriate vacuum is the exhaust, assurance that divides broken bits, also be to prevent to stick arenaceous element, equivalent vacuum is spent is to point to pouring field of the negative pressure in the process is built reasonably, make rate of air sucked in required is more than gas evolution, close solid works arenaceous, assure cast geometry dimension, shorten caky time, prevent air hole to diffuse, grown. (The cup of runner cup runner with the 5) appropriate capacity that make is to carry on the necessary tool of metallic fluid, pouring when make metallic fluid does not generate vortex flow, have the function that block broken bits, reach market of float of the impurity in metallic fluid upside of face of runner cup fluid, prevent foreign matter to fill model make air hole. 3, epilogue disappears modular whole casting is mid groovy craft is not to have surplus nearly accurate figuration, it is a collect plastic, chemical industry, mechanical, smelt and cast the much discipline system that is an organic whole project, because him level is finite, handle hope make a comment or criticism inappropriately. CNC Milling