The design that cutting tool of main shaft of high speed machine tool binds

) of 4 class above, and cutting tool and outfit clip orgnaization also need accurate dynamic balancing. But, the key that delivers torsion and keyway destroy dynamic balancing very easily, and, 7/24 awl handle of the standard is longer, very difficult implementation does not have clearance fit endlong, ask to cooperate only commonly before paragraph 70% above contact, because this cooperates face hind paragraph can have certain space, this clearance can cause cutting tool radial to beat, affect structural dynamic balancing. Key is to be used deliver torsion and have part to fixed position, to solve the dynamic balancing problem that key and keyway pose, can try to study a kind of knife / axial coupling fact cooperates to be in the attrition power with very great generation now in order to deliver torsion, the part that implements installation with the method that makes number on knife handle to fixed position, achieve the goal that cancels key. 2, the 7/24 awl coupling of the actor defect standard that standard 7/24 awl binds has a lot of advantages: Because be not locked up oneself, can come true to assemble and unassemble quickly cutting tool; The cone of knife handle falls in the action of pulling force of pull rod axial, the closely inner cone surface contact with main shaft, the cone of sincere is in directly cutting tool of internal support of aperture of main shaft inner cone, what can reduce cutting tool is dangerous extend a capacity; This kind of coupling has a measure only namely cone angle needs to machine very tall precision, inferior and cost is so reliable, will apply for years very extensive. But, 7/24 coupling also has a few drawback; Taper is bigger, awl handle is longer, cone surface should have two main effect at the same time, namely cutting tool posture is firm to the essence of main shaft reach clamp of implementation cutting tool and offer enough coupling stiffness. Because it cannot come true to locate at the same time with main shaft end panel and inner cone face, so 7/24 knife of the standard / axial awl coupling has larger space between main shaft end panel and end panel of knife handle flange. In ISO standard formulary 7/24 taper cooperates in, the angle deviation of aperture of main shaft inner cone is " - " , deviation of angle of knife handle pyramidal is " ＋ " , cooperate in order to assure before paragraph contact, so its radial locates precision often insufficient, cooperating hind paragraph still can produce gap, the AT4 class that is like a model (ISO1947, GB11334-89) taper stipulates the tolerancepublic errand value of angle is 13 ″ , this is meant after cooperating paragraph the biggest bottom clearance is as high as 13 μ M, this bottom clearance can bring about the dynamic balancing that beat and destroys a structure of point of a knife, still can form the condition that is fulcrum with contacting front, when the attrition moment of force that exceeds pulling force of pull rod axial to arise when the curved moment that cutting tool place endures, cutting tool is met previously paragraph osculatory area swings for fulcrum. Below cutting strength effect, cutting tool is in of aperture of main shaft inner cone this kind swings, before can quickening main shaft taper hole paragraph wear away, form horn mouth, cause error of fixed position of cutting tool axial. The stiffness to cone angle change that 7/24 taper binds and the change with tensile axial are very sensitive. Increase 4 ～ when pulling force 8 times when, the stiffness of coupling can raise 20% ～ 50% , but, too large pulling force meets those who quicken the aperture inside main shaft wear away in the frequent process that change a knife, make the aperture inside main shaft expands, affect the life of the bearing before main shaft. Additional, the place before be like is narrated, the awl coupling of knife handle of this kind of sincere rotates in high speed when, tensor of enlarge of ministry of main shaft end is more than the outspread quantity of awl handle, high speed performance is poor, do not suit to exceed the coupling of high speed main shaft and cutting tool. 2, the 7/24 awl coupling of the actor defect standard that standard 7/24 awl binds has a lot of advantages: Because be not locked up oneself, can come true to assemble and unassemble quickly cutting tool; The cone of knife handle falls in the action of pulling force of pull rod axial, the closely inner cone surface contact with main shaft, the cone of sincere is in directly cutting tool of internal support of aperture of main shaft inner cone, what can reduce cutting tool is dangerous extend a capacity; This kind of coupling has a measure only namely cone angle needs to machine very tall precision, inferior and cost is so reliable, will apply for years very extensive. But, 7/24 coupling also has a few drawback; Taper is bigger, awl handle is longer, cone surface should have two main effect at the same time, namely cutting tool posture is firm to the essence of main shaft reach clamp of implementation cutting tool and offer enough coupling stiffness. Because it cannot come true to locate at the same time with main shaft end panel and inner cone face, so 7/24 knife of the standard / axial awl coupling has larger space between main shaft end panel and end panel of knife handle flange. In ISO standard formulary 7/24 taper cooperates in, the angle deviation of aperture of main shaft inner cone is " - " , deviation of angle of knife handle pyramidal is " ＋ " , cooperate in order to assure before paragraph contact, so its radial locates precision often insufficient, cooperating hind paragraph still can produce gap, the AT4 class that is like a model (ISO1947, GB11334-89) taper stipulates the tolerancepublic errand value of angle is 13 ″ , this is meant after cooperating paragraph the biggest bottom clearance is as high as 13 μ M, this bottom clearance can bring about the dynamic balancing that beat and destroys a structure of point of a knife, still can form the condition that is fulcrum with contacting front, when the attrition moment of force that exceeds pulling force of pull rod axial to arise when the curved moment that cutting tool place endures, cutting tool is met previously paragraph osculatory area swings for fulcrum. Below cutting strength effect, cutting tool is in of aperture of main shaft inner cone this kind swings, before can quickening main shaft taper hole paragraph wear away, form horn mouth, cause error of fixed position of cutting tool axial. The stiffness to cone angle change that 7/24 taper binds and the change with tensile axial are very sensitive. Increase 4 ～ when pulling force 8 times when, the stiffness of coupling can raise 20% ～ 50% , but, too large pulling force meets those who quicken the aperture inside main shaft wear away in the frequent process that change a knife, make the aperture inside main shaft expands, affect the life of the bearing before main shaft. Additional, the place before be like is narrated, the awl coupling of knife handle of this kind of sincere rotates in high speed when, tensor of enlarge of ministry of main shaft end is more than the outspread quantity of awl handle, high speed performance is poor, do not suit to exceed the coupling of high speed main shaft and cutting tool. Graph knife handle of 2 　 HSK and HSK of structure of main shaft coupling are faulty also: It and structure of present main shaft end panel and knife handle are incompatible; Production precision demand is higher, the structure is complex, cost is higher (1 the price of knife handle is knife handle of average level 7/24.

5 ～ 2 times) ; Taper cooperates interference lesser (the 1/5 ～ 1/2) that is KM structure, limited speed is lower than KM structure. 2.

Improve model the coupling that devises this type is go out in order to develop to have better precision, stiffness and high speed property than coupling of common 7/24 awl, can carry ministry and knife handle with existent main shaft again at the same time compatible come out for jumping-off place design. Cone and end panel contact the WSU-1 of fixed position at the same time: This kind of design was used " fictitious taper " concept, form a cone with the dot of disperse or line namely, with surface contact of aperture of main shaft inner cone (3) seeing a picture. Realizing these component that nod line contact is stretch, accordingly, make when pulling force of pull rod axial knife handle and fixed position of main shaft end panel are contacted when, can make only knife handle pyramidal these stretch component are out of shape, knife handle is not out of shape. This kind of method can make contact awl ministry to obtain bigger interference, and do not require too large pulling force, also won't make main shaft expands, not sensitive to the pollution of interface. Graph the treatment precision of knife handle of 3 　 WSU-1 and requirement of WSU-1 of structure of main shaft coupling and 7/24 knife handle are identical, the awl ministry of knife handle still uses 7/24 taper, but its diameter wants than the diameter of taper of standard knife handle of identical flange dimension small, the outside face of awl handle covers the ball that has the identical diameter that secures by metal or plastic cage, the diameter of the fictitious awl that forms by ball compares diameter of aperture of main shaft inner cone about big 5 ～ 10 μ M, in pull rod pulling force action falls, ball happening flexibility is out of shape, till knife handle moves to be contacted till knife handle flange and main shaft end panel inside main shaft taper hole. The material of ball is metal, plastic or glass, but its make precision the demand is very high, the production precision of spherical precision and diameter is under 1 μ M, strict production precision can make sure fictitious awl and main shaft taper hole cooperate goodly. The contact of fictitious awl and main shaft taper hole is out of shape the hertz that includes ball and handle of cutting tool awl, ball and main shaft taper hole is out of shape and of ball itself be out of shape. The main good point of this kind of coupling has: Realized end panel and cone while osculatory fixed position, stiffness and high speed performance are good, main shaft won't expand, do not have an influence to bearing; Osculatory area is out of shape big, fictitious awl ministry and main shaft taper hole do not have clearance, because this arbor is jumpy small; The axial power that pull rod produces is in loss of osculatory awl ministry is small, the pressure that brings to bear on to contact end panel in cutter shaft accordingly is great, interface attrition force increases, going up somehow usable will deliver torsion, supersede the function that transmission bolts, can cancel key, have good dynamic balancing performance. In pull rod pulling force 25kN action falls, it is like interface coefficient of friction 0.

35, criterion torsion of transmissible of 50 awl coupling is as high as 360N. M, be more than the torsion that groovy milling place needs, can cancel transmission to bolt. Graph the treatment precision of knife handle of 3 　 WSU-1 and requirement of WSU-1 of structure of main shaft coupling and 7/24 knife handle are identical, the awl ministry of knife handle still uses 7/24 taper, but its diameter wants than the diameter of taper of standard knife handle of identical flange dimension small, the outside face of awl handle covers the ball that has the identical diameter that secures by metal or plastic cage, the diameter of the fictitious awl that forms by ball compares diameter of aperture of main shaft inner cone about big 5 ～ 10 μ M, in pull rod pulling force action falls, ball happening flexibility is out of shape, till knife handle moves to be contacted till knife handle flange and main shaft end panel inside main shaft taper hole. The material of ball is metal, plastic or glass, but its make precision the demand is very high, the production precision of spherical precision and diameter is under 1 μ M, strict production precision can make sure fictitious awl and main shaft taper hole cooperate goodly. The contact of fictitious awl and main shaft taper hole is out of shape the hertz that includes ball and handle of cutting tool awl, ball and main shaft taper hole is out of shape and of ball itself be out of shape. The main good point of this kind of coupling has: Realized end panel and cone while osculatory fixed position, stiffness and high speed performance are good, main shaft won't expand, do not have an influence to bearing; Osculatory area is out of shape big, fictitious awl ministry and main shaft taper hole do not have clearance, because this arbor is jumpy small; The axial power that pull rod produces is in loss of osculatory awl ministry is small, the pressure that brings to bear on to contact end panel in cutter shaft accordingly is great, interface attrition force increases, going up somehow usable will deliver torsion, supersede the function that transmission bolts, can cancel key, have good dynamic balancing performance. In pull rod pulling force 25kN action falls, it is like interface coefficient of friction 0.

35, criterion torsion of transmissible of 50 awl coupling is as high as 360N. M, be more than the torsion that groovy milling place needs, can cancel transmission to bolt. Graph knife handle of 4 　 WSU-2 devises plan better land settled this kind of program the static problem that the standard binds, to standard 7/24 awl coupling structure alters small, but the treatment precision demand of coaxial groove is higher, the problem that coupling of awl of 7/24 of the standard when high speed appears still is, because this does not suit the tie of high speed main shaft and cutting tool. 4, conclusion is opposite from above active standard knife / the axis binds and all sorts of improvement plan analysis is knowable, knife / the complexity that the main problem that axial coupling exists is function of coupling stiffness, precision, dynamic balancing, structure and production cost, to solve these problems, basically have the following 4 kinds of methods: (1) undertakes improvement to having a structure, eliminate gap of face of the coupling when coupling, improve the static performance that the standard binds; (2) sets fits tolerance strictly, increase axial pulling force, below the premise that does not change standard structure, implementation awl - the face contacts fixed position at the same time; (3) converts small taper, use hollow structure of short awl power, implementation awl - the face contacts fixed position at the same time; (4) increases cooperate beforehand interference, adopt measure to prevent main shaft to expand at the same time, improve the high speed performance of standard awl handle. These 4 kinds of methods have actor drawback each, actual in can choose different method according to need. And should make knife / axial coupling has good high speed performance, optimal way still is the standard rely on cone coupling to locate instead cone and end panel contact fixed position at the same time only, this is one kind passes fixed position plan apparently. Alleviate among them pass fixed position question, structure of the KM of German HSK structure and United States, WSU-1 is worth to draw lessons from. CNC Milling