The grinding of spare parts of thin wall of typical big diameter is machined

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In full trailer concrete pump, the part of big diameter thin wall that has a kind of typical case -- among cover (graph 1) , diameter of the aperture inside its is 202mm, external diameter is 212mm, the wall is large it is 5mm only, and this spare parts the form between each dimension precision demand is higher, ra requirement is round face surface roughness outside 0.

4 μ M, round circularity error asks to be less than outside 0.

010mm. Because spare parts wall is large thinner, when the circle outside grinding, if do not take step, constant regular meeting because clamping force, grinding force, the reason such as grinding heat, internal stress, those who make workpiece generation larger be out of shape, the treatment quality of unwarrantable spare parts. It is those who reduce a hardware to be out of shape, we the structural characteristic according to the spare parts, custom-built reasonable treatment technological process, designed special grinding clamping apparatus to adopt the special method that hold clip, OK and effective assurance the treatment quality of this kinds of spare parts. When the circle outside the grinding of 1 spare parts be out of shape analyse the appearance characteristic according to the spare parts, when using taper arbor to hold clip, workpiece falls in the action of clamping force, the radial component of force of as a result of pyramidal action generation can make workpiece is out of shape. In addition, because be when grinding, of workpiece inside writing cuts hot not easy be lost, grinding heat also is to cause metabolic of thin wall spare parts to always want an account. Because workpiece is out of shape, the workpiece after grinding can form saddle model (graph 2) , make sure workpiece circularity and coaxial spend error requirement hard, must pass design special fixture and use reasonable technology program ability to ensure the treatment quality of the spare parts. The use principle of structure of 2 clamping apparatus is shown 3 times like the graph, this clamping apparatus is arbor, go up set adjustable type construction, by arbor 1, solid a system of fixed quotas for marketing 2, different fixed position board 3, pull rod 4, gripper shoe 5, right fixed position board 6, bedspring is covered 7, pressing plate 8, the nut that take a shoulder 9 with bolt carrying silk on the head 10 composition, among them left, right fixed position board with workpiece between cooperate to be H6/h5, right fixed position board 6 with elastic sleeve 7 between cooperate to be E8/h7. Bedspring covers the inner cone of 7 to spend it is 20 degrees. When use clamping apparatus, use solid a system of fixed quotas for marketing first 2 will different fixed position board 3 fixed in arbor 1 on, go up in the installation of other one aspect of the matter of arbor next gripper shoe 5, had machined with the spare parts inside Kong Wei fixed position is standard load clamping apparatus, it is right top again board 6 outfit are on arbor and close with the Kong Pei inside the spare parts, position of 4(of two pull rod is inserted on clamping apparatus all cloth) use nut locking, originallied clamping apparatus closely to go up in workpiece so. Cover bedspring again next 7 insert arbor 1 with right fixed position board in the 6 clearance between, install pressing plate, screw the nut taking a shoulder on arbor 9, cover bedspring press, bedspring is covered can have automatic centering effect, and make the axes of the axes of arbor and workpiece keeps consistent, clamping apparatus was finished with respect to installation. After the part has been machined, loosen first the nut that take a shoulder 9, pigheaded move 10(of 3 bolt carrying silk on the head 3 bolt carrying silk on the head 10 positions all cloth, and at two pull rod 4 positions stagger) , right fixed position board can drive bedspring to cover 7 edges opposite way quits work, clamping apparatus disassembled with respect to what can go to the lavatory. When type selecting of 3 emery wheel chooses emery wheel, emery wheel character if filling of abrasive, granuality, hardness, bond, stone mill and emery wheel organization are right grinding quality is influential, if the choice is undeserved, make workpiece achieves expectant exterior surface roughness hard. Still should improve the cutting performance of emery wheel as far as possible in addition, the small blade that controls good emery wheel to be versed in tabulation face wears bead reachs his to wait tall, use hold sharp position. It is 45 steel in view of the material of this spare parts, to reduce surface roughness of spare parts surface, the granuality of chooses emery wheel abrasive wants moderate, hardness is OK a bit a few smaller. Because too hard emery wheel becomes his,this is after complete already passivation, grind bead to still cannot fall off, continue grinding makes surface roughness greatens instead. In applying actually, of emery wheel choose in order to microcrystalline corundum or single crystal corundum, hardness is intermediate (it is advisable that K) , granuality reachs 60 for 46. In addition, emery wheel must want to pass nap before use, the threshing sex that makes emery wheel surface has the good cutting blade that wear bead and small blade and wait for tall sex, ensure the exterior surface roughness of workpiece grinding asks thereby. The form that 4 treatment facilities processes to reduce a hardware error, the option of equipment is very important. Main shaft of requirement machine tool should have taller circumgyrate precision, radial and jumpy do not be more than 0.

001mm, main shaft stiffness is good, the machine tool is departmental minute of not due and oscillatory phenomenon, because this had better choose newer machine tool. Join the real case of my company, equipment chooses MB1332B common cylindrical grinder. 5 grinding fluid and cooling means are reduce heat in metal cutting, cutting fluid can be used without oil, without inferior the cooling fluid of LPG-1 efficient grinding of nitric acid accept. This cooling fluid is with extremely efficient press lubricant to regard a recipe as the foundation for additive, and from antirust, permeate, fight hard water sex, clean, disappear bubble and antiseptic wait for what the respect considers integratedly to have it is environmental protection, good to clean a gender, go it is good that oil leads tall, cooling sex wait for an advantage, can managing many energy resources and reduce emery wheel to use up, increase grinding dosage, improve manufacturing efficiency. When use grinding fluid, should use the method from fluid of cutting of supply of grinding area bottom, can make cutting fluid reachs emery wheel and the grinding area that workpiece contacts very easily already so, can make emery wheel gets cool in time and be cleaninged after grinding workpiece again at the same time, lengthen the service life of emery wheel, geometry figure that holds emery wheel thereby, can be in grinding is successive when the surface, make workpiece maintains inferior temperature, raise the appearance of workpiece and positional precision. 6 grinding dosage grinding time grinds much talk working procedure for thick, essence, when coarsen is ground, can arise so be out of shape can be able to eliminate when essence of life is ground. When grinding grinding, grinding dosage chooses to answer appropriate, when kibble, the linear velocity of emery wheel is 15~20m/s, workpiece rotate speed is 35~70r/min, floating rate is workbench 0.


05m/min; When essence of life is ground, the linear velocity of emery wheel is 10~15m/s, workpiece rotate speed is 50~80r/min, floating rate is workbench 0.


03m/min. The equipment that because choose,the clip of 7 workpiece installs is common cylindrical grinder, when using two tips to hold clip work, coaxial of aperture of two tips, two centers spends an error to will affect the treatment precision of workpiece directly, the treatment quality that the spare parts asks assures very hard. Accordingly, to because two centers aperture makes work,be eliminated the error reachs two top mounting error to be opposite the influence of workpiece circularity, when clip holds work, if the graph shows a method 4 times to choose two special centers to cover,can adopt 2, the tip covers material to choose GCr15 steel, the car goes outside the grinding after the circle, central aperture uses 60 degrees of special centers to get get, temper by dipping in water comes forcedly 60HRC, use special inside round emery wheel grinds a central aperture, grind the circle outside going out with central opening fixed position again, ra0 of surface roughness of surface of Kong Zhi of abrade center.

4, control power of Mo Shi awl. Load two special centers rear push frame of cylindrical grinder head next, choose a diameter to be 1/2 inch ball of 0 class steel, and with the graph 2 shown special fixture cooperate, the outfit that can complete work through using collet and dial is placed (graph 5) . Replace cone-shaped tip with ball of high accuracy steel, but line contact of surface contact instead, disappear machines the influence of precision to workpiece besides central aperture precision, can raise the circularity of workpiece significantly. The note   when 8 grinding (1) is ground in essence of life when, the work that causes to reduce clamping force is out of shape, when the clamping force of clamping apparatus should compare kibble a few smaller. (After 2) grinding, rust to prevent workpiece, workpiece should be done except water, eliminate foreign matter and antirust processing. (The balance of emery wheel of 3) school just in time. Emery wheel is lopsided will cause vibration, the meeting is right the form of the spare parts precision causes an effect, because this is before grinding workpiece, must of emery wheel of school just in time move, static balancing, undertake careful nap. (20~30min runs workbench and arenaceous bye before 4) grinding workpiece, make machine tool character of service stable. In empty movement while, the air platoon in wanting a vat of machine tool hydraulic pressure is clean. (Before 5) installs workpiece, should inspect two tips and work center hole coordinate a case, the central aperture wipe up that must attend two tips and work. 9 application effect this technology program is simple, economic, clamping apparatus design is reasonable, application is convenient, production cost is low, it is easy that the spare parts disassembles, versatility is strong, use effect is good, can ensure workpiece machines quality effectively already, can improve work efficiency again, comfortable Yu Dazhi diameter Bao Bi kind the batch of the spare parts is produced. CNC Milling