Exceed good treatment to what reduce point

  • Time:
  • Click:25
  • source:MAJA CNC Machining
To the treatment that reduces kind of mould point precision asks to compare tall, the point clearance precision that machines with traditional craft pattern and quality assure hard, after point quenchs exceeding good processing technique is one of ways that solve this kind of problem. Analysis of stamping workpiece quality enclothes a mould to make a process in large car in, strong cutting kind of mould into parts to should say is not the most complex, it is the mould with precision higher demand however, the space control of the point that decorate a border is the production difficulty of this kind of mould. Want to get ideal stamping workpiece, what need ensures implementation is reasonable is strong reduce gap, develop the size that reduces gap and even level, affect the mould life, strong volume that reduce force and stamping workpiece measure directly not only, still decide the section quality of stamping workpiece. The graph is shown 1 times is to develop the section case of the blemish stamping workpiece that reduces the mould place production with inhomogenous clearance. Graph 1 different to the section case that dismisses clearance stamping workpiece from the graph 1 in can see, two end are strong cut clearance into parts to be in greatly (place of the Ⅰ in the graph is shown) , area of section round horn is larger, shining belt is narrow, rupture bandwidth, have bigger taper and produce thicker burr; Rush among decide clearance small part (place of the Ⅱ in the graph is shown) , section is more vertical, shining bandwidth appears double shining belt, section periphery has thinner burr; Only two side make an appointment with stamping workpiece 1/4 is in (place of the Ⅲ in the graph is shown) strong reduce gap relatively appropriate, section quality is good, shining belt occupies the 1/3 ~ 1/2 with thick makings about, strong cut the effect into parts to achieve make a demand. From above make look, the mass that mouth of same Duan Ren builds an edge differs a lot of, explained difficulty of pilot of long border point is very great. Graph 2 strong reduce gap we know, strong reducing gap is the dimension difference that direction checks to go up in perpendicular Yu Chong between sunken model and punch, what our habit says is strong reducing gap is to point to bosseyed clearance, express with Z commonly (graph 2) : Z = D is sunken - D protruding, among them: D is die dimension. Choose rush reasonably reducing gap is the first requirement that assures stamping workpiece quality, enclothe in the car strong in cutting a mould into parts, strong cut clearance into parts to basically be decided by plate thickness, the design value that my factory often uses is: Z = (7 % of 4 % ~ ) T, t is the plate thickness of stamping workpiece. Build the stand or fall of edge quality, main decision at the following 4 respects: 1. Build the size of edge clearance and even case. 2. Repair the dimension precision of border point and verticality. 3. The surface roughness of point surface. 4. The hardness after point heat treatment. 4 kinds of circumstances divide above the 4th kind outside, the others is those who pass treatment of numerical control machine tool or benchwork long grind will come true. How to make true point machine procedure, will come true to rush reasonably reduce gap, it is to make develop the stress that reduces kind of mould. Point convention workmanship is enclothed to large car produce to what cut a mould into parts, its build foul line is complex three-dimensional curve more, the section that decorate a border is larger also, cannot use the technology such as line cut, can use treatment of numerical control machine tool only, it is more difficult also to detect, conventional point treatment technology basically has the following two kinds: 1. Strong cut kind of mould into parts to be in shape after the face is machined, punch-die point is pressed strong cut clearance into parts to come for 0 immediate treatment academic dimension, undertake quenching handling next. Finish by benchwork again assemble, detect on compressor point clearance. When detecting, be with punch fiducial, adjust by benchwork, grind the method that builds sunken model section will assure to rush reduce gap. Graph 3 handiwork trim the point after casting 2. Strong cut kind of mould into parts to be in shape after the face is machined, punch point treatment comes academic dimension, undertake quenching handling; Allowance of sunken model point 0.

2 ~ 0.

3mm, do not undertake quenching handling, finish by benchwork next assemble, punch point is used to be amended to embossing of sunken model point on compressor, sunken model wall has material to be cut after embossing, quench next, trim sunken model point by trace essence by benchwork, until strong cut into parts till space is suitable. Nextpage the advantage of two kinds of afore-mentioned methods is: Handling time is short, repeat with frequency of numerical control machine tool little, cutting tool is used up small. Defect is: The section after quenching is out of shape big, clearance of the line that decorate a border is inhomogenous, assure to achieve design requirement hard, benchwork is repaired cast workload big, point quality is poor. Especially the 2nd kind of circumstance, because sunken model point is repaired by benchwork entirely almost,become, reason point surface roughness, verticality assures hard (graph 3) . Sometimes benchwork to drive plan or horizontal issue, repair the first flank that go out to slant narrow, point intensity is low, punch after a few batch, point can appear skip blade or crackle reach clearance to wait for a phenomenon greatly, need fills afresh solder is repaired cast (graph 4) . Graph 4 point skip after the filling solder point after blade quenchs exceed good treatment to be aimed at point treatment and benchwork to grind the problem that after repairing, appears and inadequacy, join the real case of characteristic of my plant equipment and production, we undertook improvement to point treatment from craft, namely after point quenchs exceed good treatment, control the clearance that decorate a border completely by CNC Machining, made up for the wave motion of the respect such as benchwork level and physical strength, reduced the interference of factitious element, the treatment efficiency that increased long border point apparently thereby and quality. Actually manufacturer of a lot of dies also begins the research of this respect already, the key of this technology is the arrangement of technological process and the make choice of of all sorts of parameter, hope to be able to be discussed jointly. We are specific and normative as follows: 1. Working procedure arrangement. Arrangement of good treatment working procedure exceeds to be in after point quenchs model after face finish machining and point semifinishing machining are finished, undertake quenching handling next, machine tool of reoccupy numerical control has point exceed good treatment. 2. Point hardness. The hardness after point quenchs is in HRC55 ~ 65 the left and right sides. 3. Point width. Width of first flank of upper mould point is not more than 25mm, width of first flank of the point outside lower mould is not more than 20mm, width of first flank of the point inside lower mould is not more than 15mm. If width of point first flank exceeds this value, should carry on the back in the mill before quenching empty. 4.

Buccal surplus. The obligate mental allowance after point semifinishing machining is 0.

2 ~ 0.

3mm (already considered to quench heat treatment deflection) , the treatment that good treatment exceeds after point quenchs namely is measured with 0.

1 ~ 0.

3mm is advisable. Treatment has measured congress to affect treatment precision and aggravate cutting tool to wear away, surplus is too small quench be out of shape big when may short. 5.

Machine tool choice. Choose tigidity of machine tool system the contains closed circuit servo numerical control machine tool with good, tall precision. 6. Cutting tool choice. Choose cutting tool total principle is applicable, safe, economy. Below the premise that asks in contented treatment, cutting tool hangs deep length as far as possible short, cutting tool diameter as far as possible big, be helpful for reducing the surface roughness that machines the surface, in order to raise the tigidity of cutting tool system, medicinal powder heat and cutting tool life. But the cutting tool radius that should note clear finally role should be less than outline radius of the smallest curvature. Compare through the experiment, my factory chooses what the graph shows cutting tool 5 times to have point to exceed good treatment. Graph 5 commonly used super- hard the integral hard alloy that 6 blade establish milling cutter to exceed good treatment to use establishs milling cutter to contain PVD coating, common PVD coating has TiN, TiCN, TiAlN to wait, our course is compared, the cutting tool that discovery contains TiAlN coating among them uses Yu Chao good treatment is equaler. Newest of course the cutting tool of PVD coating can of cutting HRC70 quench, but because its price is higher wasteful. What choose option of detailed parameter parameter: Because manner of material of each machine tool, workpiece, cutting varies and cutting dosage changes, inspect particular case to choose different parameter. Main parameter has: π D of 1000V/ of = of S of main shaft rotate speed (R/min) , in type: V is cutting speed; D is cutting tool diameter. Fsz of = of feed speed F (Mm/min) , in type: F is every tine feed; S gives priority to axial rotate speed; Z is tooth number. The of all kinds parameter that listed place is chosen in the watch. Afore-mentioned parameter apply to flowing outline to machine, transfer in corner and circular arc surplus and hardness want place basis to reduce rotate speed and feed appropriately. Nextpage is enclothed as a result of large car use high grade alloy steel more to the point data that checks a mould, after quenching hind hardness is tall (HRC55 ~ 65) , wear away because of what this machines cutting tool forcedly to exceeding very serious also. The graph is shown 6 times is the point cutting length that we sum up and graph of cutting tool tatty, by can see in the graph, after the point length that exceeds treatment of good treatment cutting tool when exceeds 25m, this cutting tool cannot reoccupy at finish machining, the semifinishing machining after can be being used at quenching, make the surplus of finish machining decreases. If surplus is 0 even.

1mm, match again with right cooling kind, can prolong cutting tool life appropriately. Wear away as a result of cutting tool and let the account such as the knife, the need after outline is machined operates personnel to measure treatment precision, can assure to realize the precision of point and clearance when necessary through adding cutting tool to compensate. 16 exceed φ of graph 6 to establish milling cutter forcedly (TiAlN coating) wear away because exceed good treatment to machine point to theoretical size directly,exceed good treatment note, because of the surplus after this requirement semifinishing machining must even, width of point first flank also should accord with a requirement. Because point is,make in the oriented come off work of oriented aperture, because this point exceeds good treatment and oriented aperture treatment,should be in same finish in second outfit clip. The steel gender that transcends the numerical control machine tool that good treatment requires and precision should achieve corresponding requirement, want to pass the precision that VDI3441 standard can achieve, exceed good treatment to be able to lose a sense otherwise (graph 7) . Particular note is as follows: 1. Of point quench processing wants to make sure each section hardness is adjacent and consistent, machine the point precision that go out to be able to have a difference otherwise, go against the assurance of point clearance, also affect cutting tool life. Graph the machine tools of 7 Japanese OKUMA numerical control that having exceeding good treatment 2. In machining a process, should use compress air to cool and blow scrap, prevent scrap to take scathing the crucial point. 3. Point exceeds good treatment to must be in model after face finish machining is finished, if treatment is over,point of point rework face skips easily blade. 4. Because arrange mill to machine the durability of cutting tool and exterior quality and productivity to be compared,go against mill tall, and not easy generation cuts a phenomenon too, because this should use suitable mill treatment. 5. After point exceeds good treatment process to counteract treatment to finish operation personnel wants to be measured ceaselessly, assure to realize the design precision of point and clearance. Necessary time is unoccupied place still need to come true through adding cutting tool to compensate. Graph the epilogue of the point that decorate a border after 8 exceed good treatment adopts afore-mentioned measure improve and perfect, the treatment quality of the point that decorate a border gets very big rise, exterior surface roughness and first flank verticality have clear improvement (graph 8) . The foreword after be being mixed through stimulating smooth scanning to detect feedbacks, percent of pass of sharp point clearance is 97% , curve and percent of pass of clearance of R horn point are 83% , add up to a model to be achieved into power 75% , benchwork grinds repair workload to be only previously 30% the left and right sides. Point exceeds the application of good processing technique, although added the equipment station of CNC Machining when, but can the production precision that utmost ground assures point, it is the development trend that the point that decorate a border machines, also be to raise one of stamping workpiece quality, efficient ways that reduce a mould to produce cycle. CNC Milling CNC Machining