When machine tool of economy numerical control machines cam, radius of the biggest cutting tool is decided really

  • Time:
  • Click:94
  • source:OURLOVE CNC Machining
Summary: With HCNC-1HA(China in I) economy CNC Milling is exemple, from the effective treatment of contrail of cam face outline the problem sets out, combine the actual characteristic of economy CNC Milling, the affirmatory method of the radius of the biggest cutting tool that when introducing economy CNC Milling to machine cam, can use. Preface is in on numerical control machine tool when treatment cam face, the choice of cutting tool radius affects the treatment precision of cam not only, and the treatment productivity that affects a machine tool, affect machine program even whether carry out, accordingly, the choice of cutting tool radius is a serious problem that must consider. Below the machines precision condition that assures cam face, machine systematic tigidity and treatment productivity to rise, should choose the biggest cutting tool radius to undertake machining. Graph skeleton map of 1 cam part pursues inadequacy of itself of system of 1 economy numerical control is opposite sketch map of 2 case study the influence of radius of affirmatory the biggest cutting tool here with China in I CNC Milling machines the simple plane that constitutes by simple circular arc cam outline (1) seeing a picture is exemple, raise a question. Tell from craft, the cutting tool that has radius of particular cutting tool can machine the cam outline that be more than or is equal to radius of its cutting tool completely, consequently, milling cutter stands to machine this cam outline in what this uses R=5 of cutting tool radius. Partial machine program is as follows: ... G90 G42 D01(r=5) ... N009 G01 X-5 N010 G02 X5 Y-20 I5 J0 N011 G01... ... G40... try to analyse to machining the craft sex of cam and machine program, should machine, but in China in hint again and again however on I CNC Milling - " the 10th cutting tool interferes the program " , not only the treatment that cannot complete these 10 normally, and often make systematic sink dead plane position. Check above order through relapsing carefully, affirm without by accident. The cause that causes a program to cannot move normally is searched below. When system of analytic numerical control is undertaking compensation of radius of C function cutting tool runs this program, the academic moving contrail of cutting tool center and N009, N010, N011 3 block is in turn accept a case (2) seeing a picture, can discover the reason that causes this problem. Cutting tool is in N009, N010, N011 of 3 block running orbit actually is: EA linear Duan Shi shows the treatment task of N009 block, AB, BC2 straight line segment is what machine N010 block to circular arc by block of linear treatment N009 is stretchy when undertaking radius of C function cutting tool is compensated model transfer turn receive, cutting tool realizes whole semicircle in C(C) point point namely the treatment task of N010 block, CB, BD2 straight line segment is to make N010 block is machined by circular arc when compensation of radius of C function cutting tool to block of linear treatment N011 stretchy model transfer turn receive, DF linear Duan Shi shows the treatment task of N011 block. The key of the problem depends on going up to the treatment of circular arc outline, this program is the course that runs to C dot by B dot in cutting tool to the treatment of circular arc outline medium or what cutting tool nods in C is brief in staying, come true, the instruction of G03 of circular arc interpolation that make N010 block medium so did not achieve the exercise of interpolation of its circular arc, appear thereby so called " cutting tool is interfered " phenomenon, this is the prime cause that this one problem arises. Be aimed at the generation reason of this one problem in numerical control system, want to solve this problem, the cutting tool that should use radius of lesser cutting tool undertakes machining. Pursue the outline of a few cam on the project when requirement of precision of 2 cam treatment is opposite 3 treatment precision and cutting tool radius to the influence cam outline of radius of affirmatory the biggest cutting tool is joined by a series of straight line segment and be become is OK by length enough small small straight line segment. Assume office in cam take photograph adjacent two straight line segment, when cam substance when 180 ° of ≤ of A of side included angle, when machining part of adjacent of photograph of this two straight line segment, need not consider to machine the precision influence to size of cutting tool radius. When ° of A>180 of included angle of cam substance side, when machining part of adjacent of photograph of this two straight line segment, must consider to machine precision to be opposite the influence of size of radius of affirmatory cutting tool. When ° of A>180 of included angle of cam substance side, call corresponding node P hollow site, be in hollow point point, actual treatment outline is a paragraph of circular arc. Nod the treatment precision of place to make sure this are sunken, the cutting tool radius of the biggest license can press a plan 3 undertake an analysis, the dotted line circle in the graph expresses cutting tool. The machining error D=P1P=OP-OP1=r-rsina/2 that P nods assumes the radial public errand of the requirement is IT, desirable D ≤ IT/5, the Rmax=ITsina/25(1-sina/2)(1) of radius of the biggest cutting tool that can get a license from this by type (1) , OK will decide Rmax according to tolerancepublic errand IT and the biggest included angle A, and A is bigger, rmax is smaller. The music line segment that cam outline constitutes when cam outline is joined by a series of smooth music line segment and be being become can be divided it is 2 kinds, one kind is the music line segment of outward protruding, right now size of cutting tool radius does not suffer the effect of line segment of this kind of music: Another kind is inward sunken music line segment, the radius of the smallest curvature that right now radius of requirement cutting tool must is less than or is equal to music line segment and D the sum. The place on put together is narrated, when machine tool of economy numerical control machines cam, machine systematic tigidity and treatment productivity to rise, should choose the biggest cutting tool radius to undertake machining, for this precision of treatment of should integrated consideration asks and itself of system of economy numerical control is affected to what cutting tool radius chooses. CNC Milling