Foundry technology of extruding of peen of hammer type crusher and mould design

  • The first: Wu Xialing, , was born 1983, master graduate student, machinery of Beijing traffic university and electron control engineering courtyard, garden village goes up outside Beijing Xizhimen 3 (hammer type crusher is the broken machine that the industry such as cement, pottery and porcelain, mine, electric power uses extensively, peen is its wear away basically, its service life is very low, have 11~20 every year material of 10 thousand hammer is used up. Investigate its reason, besides the characteristic of its work requirement, select material and figuration craft are important facet.

    At present crusher peen basically is used common sand mold casts means or compound cast means production. Because existence is stomatic,common casting causes the peen of form, shrink blemish and the grain such as loose, shrinkage cavity are bulky, when be being pounded with hard stock in working process, get big wallop and happen burst and wear away; And compound cast peen craft complex, and oneness of joint face place is poor, easy rupture and flake, all cannot very good contented use requirement, create the great waste of material.

    Its application is in the technology that pushs die-casting to build a technology to cast and forging to be united in wedlock as a kind to be taken seriously extensively domestic and internationally. Consider to make clear, steel pledges extruding is cast character has been cast than sand mold, be close to forging character, and can obtain better economic benefits, at present already a variety of mechanical spare partses use method of extruding foundry technology to produce 11, it is to have a material of wide application foreground to shape technology.

    The performance characteristics demand that considers peen is higher, and the structure can use extruding simply to cast a technology to have production completely, in order to solve common cast the issue with peen small service life.

    The spare parts structure that the crowded die-casting of peen of crusher of 1 hammer type builds craft to design peen of crusher of type of hammer of brief introduction of peen of crusher of 11 hammer type sees material is ZMn3 quality character for 5. It is thus clear that its are ~220 not to add workpiece, length and public errand of axial hole size are strict, the wall is large inhomogenous, the product that acquires qualification of in-house and compact, dimension has certain difficulty.

    12 technology program designs the use requirement according to peen, the extruding that links the site casts the characteristic of machine, to peen extruding is cast undertake technical analysis and craft are designed.

    Extruding casts the choice of means: Peen belongs to norms the product with much, big batch. Use direct extruding can 1 model 1, manufacturing efficiency is low, ought to use indirect extruding to cast. With normally what indirect extruding differs is, peen wall is large big and inhomogenous, so, creation condition aggrandizement fills shrinking is crucial.

    For this, adopted large wall place to open inside runner, issueing implementation high to fill than pressing a condition shrink. Extrusion ratio is pressed take 200MPa to use indirect extruding, 1 model 3, symmetrical at pressing distributing equably all round the room. The extruding that this chooses friend casts type name is YS2-1250 nominal pressure for the 12 choices of cent face. According to the appearance characteristic of workpiece, cast to make squash easy from model take out in antrum, hope to obtain extruding to fill up the favorable result of figuration, the extruding after at the same time facilitating mould treatment reachs a model stay in lower mould, again the structure according to peen semmetry, use a level to part modular way, and workpiece is more than the part in upper mould antrum in part of lower mould antrum. Because want to use lower mould to support, reason takes cent side those who be in 25mm large part to go up the surface (see B) .

    The extruding that produces the spot is cast machine go up only crock and next crocks. Go up to crock pressure is as high as 12500kN and issue a crock to only 2000kN can't provide a requirement among them than pressing. According to characteristic of this one equipment, go up to make full use of crock of lock model and extruding, use the structure of float model, namely steel fluid is pouring the upper part that playing drift is pressed indoor, after the crock drives upper mould and lower mould to close on, continue be issued to lower levels, form opposite campaign with next drift, realize great pressure on the crock provides extruding force.

    Between 340~1390 ° C, its are so pouring temperature control is between ° C of 1400 ° C~1430. Extruding speed cannot too big, too congress causes gas to have not enough time eduction, bring about the generation of the blemish such as the stoma inside fluid forging thereby; Fluid forge speed cannot too small, too hour, liquid metal surface already formed thicker hard surface, bring about quality of crowded casting die not tall. Integrated consideration, it is advisable that extruding speed takes 6mm/s extrusion ratio presses the press that chooses for 200MPa place to all satisfy a requirement on pressure and speed.

    2 moulds design 21 patterns principle of structure of mould of total construction design sees main component is the mould upper mould, lower mould, drift and bedspring 4 much. To save stuff, whole pattern uses combined-type, different share differs according to the function use different data. Considering on, lower mould core damages more easily, so upper mould design is upper mould core 2 cover with upper mould 3; Lower mould design is lower mould core 12 cover the 13 heat that get as a result of drift with lower mould exhaustion and thermal stress are very great, design drift drift so 14, gripper shoe 6 space block 7 3 parts. Upper mould core 2, lower mould core 12 with drift 14 because the function needs, use H13 steeliness to build; The model covers etc to locate the part uses the tool steel such as 45 steel or TA. Through choosing different mould material to different position, can satisfy the requirement such as the intensity of the mould and stiffness already, also can fall mould cost 151. Shape equipment uses special extruding to cast machine, its nominal pressure is casting of 2 000kN this extruding to make the pattern plate on the mould structure signal of machine for force of nominal of the crock below 12500kN 3 upper mould cover 2 upper mould core fixed head of 4 lower mould 6 gripper shoe of bedspring of 5 dish form 7 space block 8 base 9. Lower mould covers 14 drift 15 model crowded crock and bottom carry a crock on the head on antrum, add the float effect of dish form bedspring and columnar bedspring, can fall in condition of indirect fluid forge, model of the lock that finish, extruding and top action.

    The working process of the mould is as follows: In the athletic process that mobile horizontal fine grain is down, drive upper mould board 1 and on, lower mould moves downward, compress bedspring, and drift 14 do not move, be equivalent to drift going up extruding metal fluid, enter through runner model antrum, finish fill model and fill shrink process. In this process, float lower mould 13 compress columnar bedspring first 10 compress dish form bedspring then 5 have metallic liquid fill model and fill shrink. Protect after approaching proper time, discharge of moved cross beam is pressed and drive upper mould 2 and 3 go up, float lower mould 12 and 13 as a result of mobile horizontal fine grain discharge pressing also is returned former, model cake of antrum part makings breaks away from drift below the screen resilience action in bedspring, to certain distance, crock leaving a top passes long ejector pin, the small ejector pin on roof of have the aid of peen from model the top in antrum goes out. Take by hand, discharge of crock leaving a top presses restoration, the small ejector pin above passes return spring and restoration lever restoration. Sweep through blowing, after clearing, new spray expects, undertake circular the next time.

    22 runner system is designed to indirect extruding, the choice of runner position and dimension and design will affect the quality of fluid forging directly. To the head of peen, mid, carry this 3 shares: Mid ply is the smallest, because this is unsuited,have 25 only open runner; Alloy fluid face should avoid as far as possible when designing runner concussion core or model wall, suffer percussive place overheat in order to prevent, and cause conglutinate metal and wear away, because this is unfavorable also,in handsome core the head of existence is opened. Another end is the largest place in 3 parts, the wall is large for 50 attribute caky finally position.

    As a result of the action of axial aperture core, axial aperture end is most first caky position, it is mid next, final ability is end the ministry is caky. Runner left to implement order in upright ministry caky with pressure deliver effectively.

    Pressure room it is to store the space of molten steel, to prevent makings cake heavy panel, considering the pressure of next crocks, press room diameter to be able to take 200mm ground only greatly most pouring quantity need, press the height of the room to should not be less than 76mm runner cross section to choose for echelon, echelon runner comes loose heat is slow, alloy fluid flow is smooth, pressure has been delivered, suit here to use. The cross section of runner accumulates a basis caky time and fill shrink principle 151 computation, should assure to fill above all model speed. The relation of speed of the steel fluid speed of runner exit and fluid forge is OK it is according to waiting for discharge principle to write: When use, extruding rate is the minorrest for 10mm/s this casts machine decision by the extruding of the spot, and allow to fill model the oldest rate is 5m/s51, calculate so that runner cut area should not be less than 628mm then. Runner is in pressure room and model the mouth that go up spends antrum to take 49mm and 35mm to be able to assure to fill so respectively model rate is stable, of facilitating pressure deliver.

    Computation of 23 ejecting force and the design that carry an orgnaization on the head to make fluid forging facilitates drawing of patterns, in model antrum all around on leave the rake that has 1 5 ° .

    The round hole part of the head because of this spare parts (see peen part drawing) will by model core is made. To reduce drawing of patterns when model the bag on core tightens force, take here model the rake of core is 04 ° again the requirement of dimension public errand that the general assures axial aperture hard. The basis is formulary 15, the bag of computation core tightens force to be as follows: P=SLqkcs ― Sin L is model core region punch) the length of the part that be tightened by the bag, mmq tightens stress to take off a bag when, MPa suggests to be 10~20MPa normally but qualitative to steel extruding, this numerical value is too little. According to the field test of early days, take it is coefficient of friction for 120MPak, aluminium alloy, zincic alloy is for 0 2~025 copper alloy 035 here is taken 035 to remove modular rake, formula is taken here (2 pools apply to peen periphery to take off a force to calculate other parameter is changeless, the ejecting force that A of rake having a model takes 1.5 ° to go up through computational peen is more than metallic fluid to be opposite model the bag close force of core and periphery take off a force the sum, satisfy a requirement. The radius error of this cavity asks to be between 0~05mm, through computation, this one requirement also is satisfied on dimension. In the use process of peen, this round hole will cover the axis in hammer type crusher to go up, if two end had had big dimension difference to destroy countershaft generation swing accordingly, model core rake took 04 ° to also consider this.

    Specific top gives an orgnaization to rely on two roof and ejector pin to come true. See the ejector pin below and roof carry join pole 9 be linked together with crock leaving a top, and the ejector pin below passes the roof above and ejector pin to give fluid forging tip model antrum.

    The gas inside 24 exhaust system antrum is in extruding process should successful eduction, cannot obtain clear-cut crowded casting die otherwise. Serious when the possibility arises a spirit appearance, the limitation such as stomatic, pinhole produces inside crowded casting die.

    In this mould design, use the principle that aeriform upgrade walks along, exhaust basically is relied on from model the Kong Hechui above core carries ministry venting plug, and from these two parts derivative air discharge duct comes true. In upper mould core 2 cover next underside of 3 with upper mould, part from 3 peen model antrum is derivative air discharge duct, aeriform eduction.

    The 25 measure that assure product measure because this dimension requirement is strict, do not machine again, so, must adopt measure to assure its dimension precision. According to the product final measure asks, in the mould the design assures measure the following times from time to tome: Consideration metal refrigeration contracts and mould be heated expands two elements, according to the field test of early days, here model the length dimension of antrum and width dimension relatively part drawing had respectively 33% with the addition of 22% . Be in pouring in the process, metallic fluid can be affected overmuch or too less only final " makings cake " ply, won't affect the measure of the product.

    The limits of on size error of aperture of spare parts head is 0 5mm to assure this, model the rake of core can be taken only control differs the fluctuation radius of aperture to be inside requirement limits in ability of 0 4 ° .

    Trial production of 3 epilogue spot proves: Use the peen that extruding foundry technology produces, can overcome not only common the blemish that casts production, like air hole, shrink loose, shrink loose, because material is different,also can eliminate the combinative area that create is easy the problem that rupture 181; The peen photograph that casts production with common sand mold is compared, its brilliant granuality raised 1 level, concussion toughness raised 20% above. The peen of methodological production crusher that because this applies crowded die-casting,builds is feasible. Use tall can get constituent compact extruding than pressing; Control is extruding speed, extruding force, reasonable decorate exhaust, can effective avoid figuration flaw, improve quality of crowded casting die.

    So, carry the option of appropriate mould design and corresponding extruder, can make extruding foundry technology is able to apply in black metal and popularize, obtain remarkable economic benefits at the same time.