High speed machines medium CAD/CAM
- source:BAGANZ CNC Machining
The influence treatment precision of precision is tall, hot distributinging limits quality of surface of small, treatment is advanced, it is the advantage that high speed machines, but the treatment common difference with the finaller than the spare parts common difference that we see a strange phenomenon is used at building model of spare parts CAD namely is big still, this is unreasonable apparently. Data switch is the prime cause that affects precision issue. The spare parts is designed by system of a CAD normally, change to another CAD system to undertake design and treatment prepare complementing next. In undertaking data transmits a process every time, need to change geometrical form and structure to another kind of format by a kind of format, some changeover are involved by ultimate public errand approximate. Because these public errand are belonged to,accumulate income, the must be the tolerancepublic errand set of spare parts model finish machining public errand 1/10 when building model of CAD spare parts accordingly. Commutative pattern, be like IGES, make the system has transition between different geometrical description. Because data sends a system to be able to be visited " advocate " data, had better let it undertake all changeover work, pass " Flavouring " the IGES that dispatchs a system will come true. Flavouring will tell a system, use the substance of what type the most possibly in IGES file. Some systems offer the IGES Flavours bill of fare of predefine, make it more apply to commonly used system. If want to reduce transition occurrence problem, among them a method is to use direct interface. Direct interface can make a system direct read the document that takes another system, if the PowerMILL of Delcam owns the direct port of the mainstream system such as CATIA, Pro/ENGINEER, UG. Because format of triangle of Stereo Lithography (STL) is very simple, the data that because this becomes some companies,likes to use exchanges a form. Some CAM system can process STL format document directly, include the PowerMILL of Delcam among them. However, the triangle of file of this kind of format arises by tolerancepublic errand, treatment surface may appear visible face piece. The acquiescent common difference that format of STL of mainstream design system uses is very general big (0.
1mm) , and after be being concealed in multiple option, easy by oversight. Accordingly, arrange low public errand to set the treatment noncombatant duty of STL file, can raise the precision that machines the surface. 2.
The affects CAD system major part of clip by cut out curved surface " medley " and into, resemble jacket by multichip what the material with complex form oversews and become is same. The attrib border precision of these curved surface affects the quality of cutting tool method of a generation directly. For example, top of a round table is a complete circle, planar coping is hexagonal, hexagonal plane is likely the limits that in coping certain place surmounts a circle, if exceed range is too big, cutting tool method can appear sharp drop, below this circumstance, the surface after treatment appears extremely possibly knife mark. 3.
The person affect a lot of CAD to use of not complete model often takes shortcut, in an attempt to shortens the model time of the model. The skill that they often use, the circle that is point of turning of oversight base interior pours wine cup, think the cutting tool that passes appropriate radius can undertake machining directly even. Actually, if use this kind of method, cutting tool just must cut acerb corner, this makes the bear of cutting tool increases abruptly, it is cutting tool 4 when undertaking linear cutting.
5 times. Some CAM system can provide the means that solve, but had better avoid to appear this kind of phenomenon, ensure CAD model expresses well and truly to need the figure of treatment. Machine this kind of circle to pour horn to had better use the cutting tool with lesser radius, be in usually, the radius of cutting tool is the geometrical dimension that the circle pours wine cup most 30% or smaller, the method of cutting cutting tool that makes corner is in more smooth-going, avoid cutting tool swerve. If use small cutting tool to machine, cutting tool bear can reduce 3 times than cutting corner directly. 4.
Although high speed treatment expanded,cannot machine diagnostic influence but the diagnostic limits of direct milling, but particularly complex to appearance model, must use EDM to machine subtle part. In addition, major part has a lot of opening, can get them directly. If offer the CAD model that treatment uses to include these features, mostly CAM system will try to machine. The most typical outcome, it is cutting tool method contains the section that does not hope to undertake milling is machined, if do not try to handle, the cutting tool when be being machined actually is sure cut aperture or pointed corner. The person that CAM is used needs to spend a lot of time to correct an error, with avoiding to repeat treatment discharge machines area and aperture area. If possible word, as far as possible the feature that does not hope to undertake milling is machined, from the eliminate in the CAD model that is used at producing cutting tool method. The CAD system that specific means inspects place to use and calm, some systems use the method that deletes a feature, some are enclothed through joining additional curved surface. 2, the research that although a lot of research organizations are machined to high speed,CAM affects to what high speed machines already had old, but still did not make clear concise definition and explanation at present. The basic jumping-off place that high speed machines is in high speed the cutting below small negative charge is compared in cutting of low speed high load capacity more material of can fast excision. Cutting of small negative charge is meant can reduce cutting force, the vibration that reduces cutting process thereby and be out of shape. Appropriate cutting tool is chosen below high-speed condition, OK the material of cutting tall hardness. High speed cutting is OK the heat in metal cutting that have the aid of cuts bits to take away much, be out of shape in order to reduce the heat of the spare parts. Afore-mentioned advantages can come true below appropriate treatment condition only. If treatment condition is impertinent, will affect the life of cutting tool, cause more serious consequence even. 1.
High speed machines the limitative element of method of cutting tool of milling of high speed of cutting tool method to arrange as follows by importance: (1) cutting tool cannot collide with the spare parts; (2) cutting bear must be in the ultimate load of cutting tool; (3) remain material cannot is more than specify the limit; (4) should avoid material excision to lead abrupt change; (5) cutting speed and acceleration must be inside the capacity limits of the machine tool; (6) cutting direction (suitable mill / go against mill) should keep constant; (7) should avoid cutting direction to change suddenly; (8) reduces shift of light locomotive trip as far as possible; (9) cutting time should be decreased to least. In the process of work out of cutting tool method of actual part, satisfy afore-mentioned requirements completely hard. In fact, when the spare parts that processes complex form, can satisfy these requirements as far as possible only, want to satisfy the requirement of outbalance above all. Finish machining returns existence to make high speed machines the problem of occurrence knife mark: As a result of the limitation of spare parts appearance, if want to indulge cutting condition, the spare parts surface after can be being machined leaves visible knife mark, although can pass the method of polishing to eliminate, violate the original intention that use high speed machines however. After undertaking rough machining and semifinishing machining, the person that CAM is used has a variety of methods to revise the figure of the spare parts, knife mark also can be used ever since finish machining is eliminated. 2.
The high speed machine program with process designing good ability is carried out quickly on the machine tool, spend a long time and much energy work out. What make in the mould is odd a treatment domain, because await machine program,bring about a machine tool to stay the case of machine very general. If force this kind of pressure,give the person that CAM is used, let them produce cutting tool method quickly, can force them to take shortcut, weaves program can have a problem, although the machine tool can continue to run, its machine speed to already sold at a discount greatly, the method that uses pressurization of the person that CAM is used so undertakes high speed is machined and unwise. If want to obtain best high speed to machine the effect, must provide adequate CAM capability, in order to get the machine program of high quality, ensure the ground runs machine tool full load. For this but from proceed with of the following respects: (1) appliance has automatic high speed machines CAM software of the function, can reduce the person that use to optimize the workload of form. (2) is used can calculate quickly the CAM software that has not had cutting tool to have way, batch processing function can remain the consideration of complex program in nightly undertake. (3) uses high-powered computer and often update configuration, ensure have enough memory to run efficiency in order to rise. (4) ensures every machine tool provides personnel of sufficient CAM process designing. Groom machine tool handlers, make them direct undertake machining process designing in the workshop, develop its in order to fill a portion to process mastery of a skill or technique. (5) ensures offer proper high speed to machine process designing to groom for handlers. 3.
Arrangement processes order besides the simplest spare parts, high speed treatment often has many to machine measure. To the process designing that high speed machines, the most important is to choose right treatment order, it is a few basic principles below. (1) considers to process the geometrical form of figuration, answer to consider the data that the hope excises at the same time. (2) decreases treatment measure to least. (3) uses continuous method, it is good that if slant,buy method compares balance method normally wait. (4) avoids perpendicular next knives, should from material exterior cut. (5) is in the critical area of the spare parts, ensure the finish machining method of different measure won't repeat, decide mark showing a knife surely otherwise. (6) does not change a knife as far as possible, use precision work of onefold cutting tool critical area. The treatment surface after cutting tool installs a mistake to often cause precision work appears knife mark. (7) grows cutting tool to wear away easily, answer to use short cutting tool as far as possible. If can, should consider way of part of new fixed position, the area that machining hard uses short cutting tool to undertake machining. 3, conclusion (the every link requirement that 1) high speed processes pair of treatment work is strict, main demand is to use appropriate physical device, appoint concerned parameter accurately. Although hard specific appoint high speed treatment to need what CAD and CAM function, the quality that can be sure CAD and CAM are machined to high speed however and stability all have apparent effect. (The CAD model that treatment of 2) high speed uses must convey the model figure that needs treatment accurately, precision of this interest model must prep above machines precision, below probable condition, the model trait that will not need to undertake milling is machined is deleted or cover. (Facilities of treatment of 3) high speed must match with personnel of sufficient CAM process designing, in order to make sure the machine tool uses first-rate program. Raise one of methods of process designing quality, it is to let a machine tool machine personnel to weave in the workshop machine program, ensure CAM handlers and machine tool operate personnel at the same time, once accepted good technology to groom. (If 4) wants to obtain good high speed to machine the effect, the most effective method is order of careful arrangement treatment, use the treatment condition that CAM system offers appropriately. CNC Milling