The structure of numerical control machine tool asks

Published on 2018-01-26

 Machine tool noumenon is the main body part of numerical control machine tool. Come from all sorts of motion at numerical control device and behavioral statement, must come true by changeover of machine tool noumenon solid, accurate mechanical movement and movement, ability realizes the function of numerical control machine tool, make sure the function of numerical control machine tool asks.

   The machine tool noumenon of numerical control machine tool comprises by following and departmental cent:

   (1) advocate transmission system, its function is implementation advocate motion.

   (2) feed system, its function is implementation feed motion.

   (Foundation of 3) machine tool, point to lathe bed, base, pillar, slide carriage, workbench to wait normally. Its function is bearing machine tool noumenal 0, component, assure these 0, the accurate place that the component has in cutting treatment process.

   (4) realizes the device of certain part movement and certain and auxiliary function, be like hydraulic pressure, pneumatic, lubricant, refrigeration and defend, the device such as platoon bits.

   (5) realizes the device that workpiece circumgyrate, graduation locates and accessory, be like circumgyrate workbench.

   (6) knife library, tool carrier and trade knife unit automatically (ATC) .

   (7) automatic tray exchanges unit (APC) .

   (Device of 8) special function, if cutting tool damaged detects, precision detects and supervisory and control arrangement.

   Among them, machine tool foundation, advocate the auxiliary unit such as transmission system, feed system and hydraulic pressure, lubricant, refrigeration is the machine tool that makes numerical control machine tool noumenal main part, other part presses the function of numerical control machine tool and need to choose. Form although the machine tool of numerical control machine tool is noumenal basically very as similar as traditional machine tool, but because numerical control machine tool is in,the requirement on function and function and existence of traditional machine tool are worn huge gap, so the machine tool noumenon of numerical control machine tool is on total position, structure, function have a lot of apparent difference with traditional machine tool, appeared a lot of completely original rigid structures that get used to characteristic of function of numerical control machine tool and component.

   Numerical control machine tool is a kind of high accuracy, efficient automation treatment facilities. Although price of numerical control machine tool is high, one-time investment is huge, but still make manufacturer place is used generally and obtain very good economic benefits for machinery, its reason depends on numerical control machine tool can automation ground, high accuracy, high quality, efficient the treatment problem that the ground solves medium, small lot. The development of numerical control technology, servo drive technology reachs the application on the machine tool, the automation that is numerical control machine tool, high accuracy, efficient offerred possibility, but should turn possibility into reality, must ask the rigid structure of numerical control machine tool has admirable characteristic ability to assure. The static stiffness that these character include a construction, fight brace up precision of the attrition character when the gender, smooth sex that thermal stability, low speed moves and motion, geometry, transmission precision.

   One, the static stiffness that improves machine tool composition

   The static stiffness of machine tool structure is to show the action in cutting force and other force falls, ability of metabolic of machine tool resistance.

   The machine tool is in treatment process, suffer the effect of a variety of outside force, obstruction of the power of self-prossessed, cutting that includes athletic component and work, driving force, force when adding decelerate, attrition. Each component of the machine tool is out of shape generation below the action of these force, like each foundation bend and seize change form, of bearing component local be out of shape, the contact of fixed join face and face of athletic clench the teeth is out of shape etc. These is out of shape direct or the metropolis is indirect the ground is caused opposite displacement arises between cutting tool and workpiece, destroy the proper place that cutting tool and workpiece have so, affect the machines precision and cutting process character of the machine tool thereby, so, the static stiffness that raises a machine tool is the global demand that machine tool structure designs. Numerical control machine tool is obtain efficient and had high-power and high rate, make its place susceptive all sorts of outside force load are more abominable, and the automation that machines a process also makes amend and machining error cannot be compensated by artificial interpose, so, of numerical control machine tool be out of shape more can serious to machining the influence of precision. Obtain stable high accuracy to make sure numerical control machine tool is below automation, efficient cutting condition, its machinery structure should have taller static stiffness, the stiffness coefficient that the standard provides numerical control machine tool should compare % of similar tall 50 of general accuracy machine tool.

   1. Reasonable design foundation sectional appearance and dimension, use reasonable muscle to harden compose

  The machine tool falls in the action of outside force, each foundation will bear to bend and turn round load, the size that its bend and seizes change form depends on foundation sectional fight bend and fight seize inertial moment, defy a turn, fight seize inertial moment big, be out of shape small, stiffness is tall. Watch 5-1 listed in cut area identical (namely weight is identical) when, the inertial quadrature of different and sectional appearance and dimension. By the data in the watch knowable: When appearance and cut area are same, reduce a wall thick, increase sectional outline size, can increase stiffness greatly; Close sectional stiffness far outclass does not close sectional stiffness; The circle is fought sectionally twist square of stiffness prep above sectional, the stiffness that defy a turn criterion under square sectional; Rectangular and sectional in dimension old way has the very tall stiffness that defy a turn. Accordingly, through reasonable design sectional appearance is mixed dimension, can increase a base greatly structural static stiffness.

  Graph 5-1 place shows the lathe bed that is lathe of numerical control of series of SL of machine of Japanese dark essence sectional, lathe bed slideway tilts decorate, improved the condition that discharge bits, at the same time sectional appearance is used enclosed casing structure, increased lathe bed thereby sectional outside outline dimension, make this lathe bed is had very tall defy a turn, fight twist stiffness. This kind tilts the structure that decorate is used generally for place of numerical control lathe.

   Graph 5-2 place shows the structure of casing type pillar that uses generally for horizontal machining center. Look from the front, pillar is sectional into close casing form, outline size is large, assure thereby with tall turn round stiffness to bear cutting torque arises turn round load. From look down at sectional look, two pillar are sectional appearance is rectangle, because cutting strength effect produces the old way that curves load,the way with rectangular old dimension is. Consequently this kind of structure has very tall stiffness.

   Reasonable decorate a foundation muscle board can raise static stiffness, watch 5-2 gave out a few kinds of pillar differ the relatively static stiffness when muscle board is decorated. From inside the watch knowable: Fore-and-aft muscle board can raise pillar fight bend and fight twist stiffness, rise fight twist stiffness effect more remarkable; Muscle of diagonal inclined buy board with diagonal across muscle board is opposite the stiffness that raises pillar is more effective.

Express 5-2 Differ the static stiffness of the pillar when muscle board is decorated is comparative

   Graph 5-3 place shows the cross section picture that is pillar of machining center of two kinds of vertical. Because this pillar bears,crankle combines load, reason is sectional use those who near a square to close appearance, defy a turn to rise further, fight twist stiffness, interior used wall of inclined square double deck (be equivalent to inclined fore-and-aft muscle board) with diagonal across muscle board. So, these two kinds of pillar have very tall defy a turn, fight twist stiffness.

(A)XK-716 vertical machining center;   (Machining center of B)STAMA MCll8 vertical
Graph 5-3  Pillar cross section

   Reasonable decorate muscle board to still can increase a base local stiffness, graph 5-4 place is shown for machine of Japanese Mitsui essence the HS 6A lathe bed structure that exceeds machining center of horizontal of accurate heavy cut to use. This lathe bed is integral type construction, sectional for structure of shape of fully sheathed case, integral structure stiffness is very tall. To strengthen slideway connective local stiffness, use two inclined muscle that become Y entity to prop up slideway.

Graph 5-4 The lathe bed structure of HS 6A of Mitsui essence machine machining center

   2. Use reasonable structural position, improve the position getting power of the machine tool, raise the static stiffness of the machine tool

   In cutting force, self-prossessed substandard force same situation falls, if can improve the position getting power of the machine tool, reduce be out of shape, can achieve the goal that raises stiffness. It is with machine tool main shaft exemple, in other condition changeless circumstance falls, shorten of main shaft front dangerous extend length, can reduce main shaft susceptive to bend quadrature, reduce the deflection of main shaft front thereby, raise the stiffness of main shaft.

   Use position of reasonable machine tool structure, can improve the condition getting power of the machine tool significantly, raise the stiffness of the machine tool.

   Graph 5-5 place shows the position of lathe lathe bed that is a tradition (5-5(a)) seeing a picture and layout of lathe bed of numerical control lathe (the analysis of the state getting power of 5-5(b)) seeing a picture is compared.

Graph 5-5 Layout of lathe lathe bed

Set area of lathe bed cut and inertial quadrature and its place to suffer cutting force P equal, to traditional lathe, layout of lathe bed level, lathe bed place suffers torque to be:

     (5-1)

Logarithm accuses lathe, lathe bed tilts layout, set dip angle for β , lathe bed place suffers torque to be:

      (5-2)

   Compare style (5-1) and type (5-2) can see, use tilt the torque of susceptive of place of lathe bed of numerical control lathe of layout wants to compare the traditional lathe lathe bed that uses horizontal position should small, consequently the stiffness of the machine tool got rising.

   The structural position that graph 5-6 place shows the horizontal boring milling machine that is a tradition and horizontal machining center (horizontal changes milling machine of boring of knife numerical control automatically) the comparison of structural composition.

   Traditional horizontal boring milling machine because bosseyed suspension is in main shaft box pillar flank, main shaft box is self-prossessed will make pillar bears curved quadrature, cutting force will make pillar bears torque, and inside the symmetrical face that the layout of machining center makes the main shaft center of main shaft box is located in pillar, pillar bears no longer the torque that by main shaft the curved quadrature of self-prossessed generation mixes box to arise by cutting force, improved the condition getting power of pillar thereby, reduced pillar bend, seize change form, raised stiffness.

Graph 5-6 The structural composition of horizontal boring milling machine and horizontal machining center is compared

   3. Compensation is concerned 0, the static force of the component is out of shape

   Below the action of outside force, of the machine tool be out of shape is inevitable, if can adopt measure metabolize to be reduced to machining the influence of precision, its were equivalent to raising the stiffness of the machine tool as a result. According to this one train of thought, produced a lot of compensation to concern 0, the method of static force metabolic of the component, this kind of method is used generally at because self-prossessed and those who cause is static,be being compensated force is out of shape.

   Be like the large planer-type milling machine that graph 5-7 place shows, move when main shaft component when crossbeam is mid, of crossbeam bend be out of shape (below sunken) the biggest. It is this to be able to process crossbeam slideway mid and raised parabola form, perhaps assist Liang He through be being installed in crossbeam interior beforehand corrective bolt dominant course preliminary adjustments corrective for convex parabola form, can compensate shift of main shaft box to go to what cause when crossbeam is mid to bend so be out of shape (graph 5-7(a)) .

   To compensate the influence with main shaft self-prossessed box, also can use add counterbalance piece or the method of other counterbalance, quits part is direct action what go up at crossbeam is self-prossessed, because main shaft box is self-prossessed,reduce crossbeam thereby cause bend be out of shape (graph 5-7(b)) .

   4. Raise a machine tool the osculatory stiffness of each component

   In the machine tool the fixed join face of each component is mixed between the combinative scale of kinematic pair, total meeting existence is macroscopical and microcosmic and rough, what contact truly between two faces is only a few high point, the area that contacts an area actually to be less than two osculatory surfaces (nominal interface is accumulated) , accordingly, when bear the weight of, the intensity of pressure that action nods at these contacts should compare average intensity of pressure to be gotten greatly much, produce a contact to be out of shape thereby. P of average intensity of pressure and be out of shape of δ contact stiffness than calling, namely

     (5-3)

   Because the machine tool always has number more static, change join face, if raise osculatory stiffness carelessly, the contact of each join face is out of shape the integral stiffness that can reduce a machine tool greatly, produce very adverse effect to machining precision.

Graph 5-7 Crossbeam bends be out of shape compensation

   Affecting the prime factor that contacts stiffness is the size that contacts an area actually, any methods that increase actual contact acreage raise osculatory stiffness effectively. If the slideway of the machine tool often uses artificial shovel to blow craft to regard final precision work as working procedure, grind through blowing, can increase the contact on unit area to nod, make contact a dot to distributing even, increase the actual interface of scale of slideway deputy union to accumulate thereby, raise osculatory stiffness. If use scroll bearing,regard the main shaft of bearing as the component again, want a design to tighten clearance of structural adjustment bearing beforehand, make bearing is in have the movement below the requirement that imposes load beforehand, in order to raise the bearing stiffness of main shaft. Added load to increase the area that actual contact selects beforehand, achieve the goal that raises osculatory stiffness thereby. Use the fixed join face that whorl originallies closely, reasonable decorate a certain quantity of bolt, right of bolt screw pitching moment raises strict requirement in order to assure proper tighten force beforehand, also be the measure that contact stiffness to rise and often adopts.

   5. Use armor plate to solder structure

Long-term since, machine tool foundation basically use cast-iron. In recent years, solder with armor plate the structure is replaced cast-iron the trend expands ceaselessly, from begin to be in odd with small lot heavy-duty apply with what exceed heavy-duty machine tool to go up, work up arrives the medium-sized machine tool that has certain lot.    

Watch 5-3 listed lathe of Star-Turn1200 numerical control solders lathe bed and the comparative result that cast the stiffness of lathe bed. Look from the result, solder the stiffness prep above of lathe bed casts lathe bed. This is the muscle because of two kinds of lathe bed board decorate different, armor plate solders the structure that the structure adopts machine tool of numerical control of the 5th regulation easily and drive are used most the muscle that is helpful for raising stiffness board decorate a form, wainscot of can sufficient play is mixed of muscle board bear the weight of reach counteractive metabolic action; Solder the structure still need not cast what structural place needs to give arenaceous opening, likely the foundation the box shape structure that make it closes completely. Additional, the stretch E feeling a quantity of armor plate is MPa, and cast-iron stretch model measures E only MPa, both differ almost one times, e= σ / ε , when stress σ is identical, the ε of meet an emergency that E produces greatly is small, the size of E reflected ability of metabolic of material resistance flexibility. Accordingly, when the structure is identical, the material stiffness with E great value is tall.

Express 5-3 Solder lathe bed and the stiffness that cast lathe bed are comparative

2, improve machine tool composition fight brace up quality

   The oscillatory meeting of the machine tool is being machined workpiece surface leaves Zhen Wen, affect the exterior quality of workpiece, serious when make machine a process to undertake going down hard. The possibility when the machine tool machines arises the vibration of two kinds of forms: Force vibration and self excited vibration. Of the machine tool fight brace up what the gender points to is counteractive these two kinds of oscillatory ability.

   Forcing vibration is in all sorts of dynamic force (the unbalance that is like spare parts of high speed circumgyrate, reciprocate the cutting force of inverting wallop, periodic change) the vibration that is forced to arise below action. If the frequency of dynamic force and machine tool the natural frequency coincide of some component, will produce resonance. The ability that resistance of machine tool structure forces vibration can be used move stiffness size to express.

   Self excited vibration is to sending the case that has adscititious and dynamic power, what arouse by place of cutting process oneself is oscillatory. The frequency of self excited vibration is close to or machine tool of summary prep above advocate of vibration shape low rank natural frequency, amplitude is bigger, produce very adverse effect to machining a process. When speed of angle of cutting of the stiffness when the machine tool, cutting tool, workpiece and cutting tool material, cutting and feed are certain, the main factor that affects self excited vibration is cutting width B, accordingly, OK a width of the biggest cutting that does not produce self excited vibration, call critical cutting width, regard judgement as stability of machine tool cutting (the ability of counteractive self excited vibration) index.

   High speed cutting is the direct ingredient that produces dynamic power, puissant cutting also means cutting width big. While numerical control machine tool is going after efficiency of high rate, tall cutting, also bury the parent that played easy generation forced vibration and self excited vibration. The automation of cutting process makes again oscillatory hard by will control and be eliminated artificially, the Gao Kangzhen sex that numerical control machine tool relies on structure of oneself machine tool only will reduce and overcome vibration to be opposite the influence that machines process of precision, treatment.

   Raise a machine tool fight brace up quality, can from rise static stiffness, natural frequency and increase damp a few respects begin. The measure that raises static stiffness already had detailed introduction in front. Because of natural frequency (among them, k is static stiffness, m for tractor dry mass) , when raising static stiffness so, can reduce the weight of structural member relatively, raise the stiffness of unit weight namely, can increase natural frequency. What introduce in front is reasonable decorate muscle board, use armor plate to solder the structure measure that raises static stiffness, can achieve the goal that raises natural frequency likewise. The measure that numerical control machine tool is adding damp respect to adopt basically will introduce below.

   1. Foundation lumen fills up the damp material such as slimy core, concrete

Graph 5-8 The dynamic character of lathe bed of two kinds of lathe is compared

   In the foundation lumen fills up slimy core, concrete, opposite attrition can be used to come when vibration dissipation vibration energy, the damp that improves a composition thereby is characteristic. Graph 5-8 place shows the contrast that reachs dynamic character for structure of lathe bed of two kinds of lathe, fill up the lathe bed damp of slimy core increases significantly. Graph 5-9 place shows the base that is lathe of DNE 480L numerical control and lathe bed structure, of the concrete that fills up inside base inside attrition damp is taller, match the lathe bed with Feng Sha again, make the machine tool has taller fight brace up quality.

   2. The surface uses damp coating

   To curving vibration structural member, the stuff sticking sluggish that in its exterior spray has Buddhist nun of taller internal resistance and taller flexibility one layer (the puddle that is like bitumen radical to be made is decreased brace up polymer of agent, high polymer and paint be bored with child etc) , coating ply heals big, damp heals big. Use damp coating, can not change the structure of original design and stiffness already, can obtain taller damp to compare again, its damp can amount to 0.05~0.1 than ξ value. This kind of measure is commonly used the structure that solders at armor plate.

   3. Use new material to create a base

   Come 10 years recently, germany and Switzerland create a base in applied polymer concrete headway was gained in research. German cloth pattern breaths out Te Weibeier (BURKHARUT&WEBER) company made lathe bed of acrylic colophony concrete for HYOP80 NC W machining center, its move stiffness to compare cast-iron 6 times taller. Accurate grinder of Switzerland produces manufacturer Si Tude (the colophony concrete lathe bed that STUDER) company made S40 and cylindrical grinder of S50 series numerical control, have stiffness tall, fight brace up the gender is good, be able to bear or endure chemistry corrodes the characteristic with heat-resisting.

   4. Make full use of the damp between joint face

   Soldering on the structure, wainscot is mixed use between muscle board discontinuous solder (namely solder a paragraph, empty a paragraph, again solder paragraph) , chafe each other when that paragraph of empty vibration, can waste oscillatory energy, acquire good damp character thereby.

 3, the heat that reduces a machine tool is out of shape

Heat expands is the inherent character of all sorts of metals and metalloid material. When the machine tool is working, a lot of components and place can produce a large number of quantity of heat, wait like system of the bearing of electric machinery, scroll, cutting position that cuts bits and cutting tool and work, hydraulic pressure. These generation caloric components and place call heat source. The quantity of heat that heat source produces is passed conduct, each parts that convection, radiate delivers a machine tool, cause temperature rise, generation heat expands. Distributing as a result of heat source inhomogenous, the quantity of heat that each heat source produces differs, component everywhere quality is uneven, fashion a machine tool each place temperature rise is abhorrent, produce inhomogenous temperature field and inhomogenous heat to expand thereby be out of shape, as a result destroys the correct and relative position of cutting tool and workpiece, the influence machines precision.

   Machine tool of tradition of outclass of speed of the main shaft rotate speed of numerical control machine tool, feed, and big cutting dosage arises cut bits fierily much also, reason is calorific far more traditional machine tool is serious, and heat is out of shape the influence to machining precision often is amended by handlers hard, because this pair of heat that how reduce a machine tool are out of shape,should give take seriously particularly.

   1. Improve machine tool layout and structural design

   (1) uses hot symmetrical structure

   This kind of structure is opposite heat source is semmetry. Be out of shape in generation heat so when, the position that can assure workpiece or line of semmetry of cutting tool centre of turning circle is changeless, reduce heat to be out of shape thereby the influence to machining precision. The most typical example is the structure of casing type double pillar that place of a lot of horizontal machining center use, main shaft box is built-in inside casing type pillar (5-9) seeing a picture, and with pillar left, right slideway two inside fixed position, when heat is out of shape, main shaft center keeps changeless in the position of horizontal way, reduced hot metabolic effect thereby.

   (2) is used beforehand the structure of ball guide screw of drawing

   The ball guide screw in numerical control machine tool is increasing load beforehand big, rotate speed is high, medicinal powder of the job below the condition of hot difference, give out heat easily, the fixed position precision of the system of feed of hot stretchy and immediate impact of ball guide screw. Use beforehand the heat that the method of drawing can reduce guide screw is out of shape. This kind of method is to be when treatment ball guide screw, make pitch is less than nominal value slightly, when assembling, undertake to guide screw beforehand drawing, although its pitch value reachs nominal value, when be heated of guide screw job, guide screw pulled stress mediumly to compensate thermal stress, reduce heat thereby stretchy.

   (3) is when machine tool layout, reduce inner heat source as far as possible

   Of inner heat source giving out heat is to cause hot metabolic main reason, accordingly, answer to consider to go out heat source from the depart in lead plane as far as possible in design of machine tool layout, if stand electromotor, gear-box, hydraulic pump,wait for lead plane of park machine tool beyond.

   The ablaze that machines process place generation is eager bits is a heat source that cannot ignore. When machine tool layout, lv of take an examination makes discharge bits unobstructed, outside should installing unit of automatic platoon bit to discharge a machine tool with will cutting bits at any time, answer to install adiabatic shield on workbench or slideway at the same time, make numerical control technology

The segregation of quantity of heat that cuts bits is outside the machine tool. The inclined lathe bed that the numerical control lathe that graph 5-10 place shows uses, smooth lathe bed and inclined slide structure, configure declining shield and unit of automatic platoon bit, it is the typical case of this one measure.

(A) inclined lathe bed;   (B) makes the same score lathe bed and inclined slide
Graph 5-10  The lathe bed of numerical control lathe reachs slide structure

   2. Control temperature rise

   Calorific to the machine tool place is adopted medicinal powder the cold, liquid cooling way that controls temperature rise comes to hot, wind the quantity of heat that absorbs heat source to give out, be one more kind is used to reduce heat to be out of shape on machine tool of of all kinds numerical control the countermeasure of the influence. Among them, compulsive refrigeration is more effective method. Alleged and compulsive refrigeration, use cooling device to undertake cooling to lube or cooling fluid namely, send lubricating oil to attrition next deputy lubricate or send cooling fluid to cutting position refrigeration.

   3. Heat is out of shape compensation

   Forecast heat to be out of shape the rule, build mathematical model to coexist undertake real time is compensated in person computer. Heat is out of shape auxiliary correction unit already served as commodity to offer money on foreign product, graph 5-11 place shows the heat that is Japanese Osaka machine to be out of shape automatic compensation amends device.

   4, improve athletic slideway deputy attrition is characteristic

   Machine tool slideway is a machine tool one of element of basic structure. The treatment precision of the machine tool and service life depend on greatly the quality of machine tool slideway, and have higher demand to the slideway of numerical control machine tool, be like: When high speed feed not oscillatory, do not crawl when low speed feed; Have tall sensitivity, long-term and successive job can leave in burden; Wearability wants tall, precision maintains a gender to be close friends etc. These as deputy as slideway attrition character are concerned, requirement coefficient of friction is small, the difference of coefficient of static, kinetic friction is little. The guide that machine tool of contemporary numerical control uses basically has plastic sliding slideway, roll slideway and static press slideway.

   (One) plastic sliding slideway

   The plastic sliding slideway that numerical control machine tool uses has cast-iron – plastic sliding slideway and set steel – plastic sliding slideway. Plastic sliding slideway is commonly used in slideway on deputy athletic slideway, to it suitable metallic slideway is cast-iron or steel is qualitative. Cast-iron brand is HT300, exterior temper by dipping in water comes forcedly HRC45~50, grinding of exterior surface roughness comes 0.20~0.10; The slideway that set steel is commonly used 50 steel or other alloy steel, temper by dipping in water comes forcedly HRC58~62. On slideway plastic and commonly used get together coating of slideway of soft belt of slideway of 4 fluorine ethylene and annulus oxygen wear-resisting two kinds.

(A) axial is compensated;   (B) pillar heat balances compensation
Graph 5-11  Heat is out of shape automatic compensation device

   1. Get together soft belt of slideway of 4 fluorine ethylene

   Get together soft belt of slideway of 4 fluorine ethylene is with getting together 4 fluorine ethylene is matrix, join the filler such as molybdenum of bronze pink, 2 vulcanization and black lead to mix agglomeration, and make it is soft banding. This kind soft contain the following characteristic:

   (1) attrition character is good

   Graph 5-12 is opposite for institute of Guangzhou machine tool the attrition speed-distance curve that deputy experiment of 3 kinds of different attrition measures, the Turcite-B in the graph and TSF are American glow respectively board (of SHAMBAN) company and production of institute of Guangzhou machine tool get together soft belt of slideway of 4 fluorine ethylene. Can see from the graph, use get together the attrition of soft belt of slideway of 4 fluorine ethylene deputy coefficient of friction is small, difference of coefficient of static, kinetic friction is little, and curvilinear slope is be worth. This kind of good attrition character can prevent slideway low speed to crawl, make move to be mixed smoothly obtain tall fixed position precision.

Graph 5-12  Attrition – speed-distance curve
1 cast-iron – cast-iron (engine oil) ;  2, Turcite-B- is cast-iron (do attrition) ;
3, Turcite-B- cast-iron (engine oil) ;  4, TSF- is cast-iron (do attrition) ;
 5, TSF- is cast-iron (engine oil)

   (2) wearability is good

   Get together 4 fluorine ethylene slideway contain molybdenum of bronze, 2 vulcanization and black lead in soft belt, itself is had self-lubricating action, not tall to the fuel delivery requirement of lube. In addition, plastic quality of a material is softer, even if is built-in metal drossy, dirt, also do not send face of scathing metal slideway and soft tape itself, can lengthen slideway deputy service life.

   (3) is decreased brace up the gender is good

   Plastic damp character is good, its are decreased brace up deputy to raising slideway opposite motion speed has the property of noise elimination very great sense.

   (4) craft sex is good

   Can reduce the hardness that treats stickup and plastic metal matrix and exterior quality demand, and plastic machine easily (mill, dig, grind, blow) , make slideway deputy interface acquires good exterior quality.

   The use craft of slideway soft belt is simple. Above all, slideway stickup face machines the surface that is 3.2~1.6 to exterior surface roughness, to have fixed position effect to soft belt, stickup face should machine slideway the groove with deep 0.5~ 1.0mm, if pursue,5-13 place is shown. Next, clean with benzine or metallic cleaner or acetone stick after accepting a scale, with adhesive agglutinate, fold again after hour of 1~2 of the solidify at the beginning of pressurization on the fixed slideway of conjugate or special fixture, inflict is certain pressure, issue solidify 24 hours in room temperature, get off cleared more than glue, can leave oil groove and have precision work. As a result of this kind of slideway soft belt uses stickup method, reason customarily is called ” the slideway that stick model ” .

Graph 5-13 Soft belt of slideway stick receive

   2. Coating of slideway of annulus oxygen wear-resisting

   Coating of slideway of annulus oxygen wear-resisting is with 2 vulcanization with epoxy resin molybdenum is matrix, join plasticizer, mix fluid shape or cream shape is a group portion, it is another group of double sets of the portion with solidify agent the portion is plastic coating. It has good machinability, but classics car, mill, dig, get, grinding and scrape treatment; Also have good attrition character and wearability, and compressive strength than getting together soft belt of slideway of 4 fluorine ethylene wants tall, the bulk when solidify is not contractive, dimension is stable. Can have adjustinging coating of the infuse after the relevant position precision between fixed slideway and athletic slideway especially, can save a lot of treatment man-hour so, reason it is special apply to heavy-duty machine tool and what cannot use slideway soft tape is complex cooperate model face.

 The use craft of wear-resisting slideway coating is very simple also. Above all, if graph 5-14 place is shown,become jack plane of slideway coating surface or thick mill

Graph 5-14 Note model slideway
1, slide carriage; 2, glue; 3, the layer that note model

rough surface, have good conglutinate power in order to assure. Next, as suitable as plastic slideway metallic slideway face (or mould) silicone oil of on the besmear after be being cleaned with solvent one layer or agent of special drawing of patterns, stick with wear-resisting coating in case receive. Material wipes the wear-resisting coating that will join solidify agent mix up by the recipe to go up at slideway face, next superposition is in metallic slideway face (or mould) aspirant travel solidify. The pattern plate that forms oil groove, oil pocket to use can be placed before superposition, solidify after 24 hours, can depart two slideway. Coating sclerosis can undertake be machininged next after 3 days. The relative position precision of the ply of coating face and slideway face and other surface but have the aid of tall piece or special fixture assures. As a result of this kind plastic slideway uses besmear to blow or infuse creams the method with plastic shape, reason customarily is called ” besmear model slideway ” or ” the slideway that note model ” .

   (2) scroll slideway

   Scroll slideway has coefficient of friction small (be in commonly 0.003 control) , move, static friction coefficient differs small, and the effect that suffers athletic change scarcely, fixed position precision and sensitivity are tall, it is good that precision maintains a gender wait for an advantage. The scroll guide that machine tool of contemporary numerical control often uses has roll slideway piece and linear scroll slideway two kinds.

   1. Scroll slideway piece

   Roll slideway piece is the scroll slideway that body of a kind of scroll makes a loop move, its structure is shown like graph 5-15 place. 1 to prevent fender, end is built 2 with oriented piece 4 lead scroll style (roller 3) is returned, 5 to maintain implement, 6 for noumenon. When using, roll slideway piece installation is on the slideway face of athletic component, each slideway uses two at least, the amount of slideway piece depends on the length of slideway and laden size, to it suitable slideway is multi-purpose set steel to quench slideway. When athletic component is mobile, roller the slideway face in bearing component and 3 noumenon 6 between scroll, confuse reality again at the same time 6 loops scroll, roller the face does not contact the 3 slideway with athletic component: Consequently this slideway face does not need temper by dipping in water hard burnish. Roll the characteristic of slideway piece is stiffness tall, carrying capacity is large, facilitate tear open outfit.

Graph 5-15 Roll the structure of slideway piece
1, prevent fender; 2, upright lid; 3, roller; 4, oriented piece; 5, maintain implement; 6, noumenon

   2. Linear scroll slideway

   Linear scroll slideway is in recent years new slideway of occurrence a kind of scroll, its structure is shown like graph 5-16 place, main by 4 of 7 of slideway body 1, slide block, ball, maintain implement 3, end is built 6 wait for composition. Be together bearing slideway and athletic slideway combination as a result of it, the standard slideway deputy component that serves as independence (unit) by special production manufacturer is made, friend calls unit type linear scroll slideway again. When using, slideway system is fixed moving on the component, slide block is fixed go up in athletic component. When system of slideway of slide block edge moves, ball rolls inside the circular arc straight chamfer between slideway body and slide block, build the raceway inside to arrive from working load area through end area of blame work load, roll again next a labour The structure of numerical control machine tool and drive make laden division, circulate ceaselessly, mix slideway style thereby the shift between slide block, became the scroll of ball.

Graph 5-16 The structure of linear scroll slideway
1, slideway body; 2, flank gaskets; 3, maintain implement; 4, ball;
5, the gaskets that carry a department; 6, upright lid; 7, slide block; 8, lube cup

   Unit type rolls slideway eliminates the general character advantage that has common roll guide point-blank outside, still have the following characteristic:

   (1) has self-regulated to make ability, installation tool reference plane is allowable the error is big.

   (2) production precision is tall.

   (3) but high speed moves, traversal speed can be more than 60m /min.

   (4) can maintain high accuracy for long.

   (5) can increase load beforehand, raise stiffness.

   (3) static press slideway

   Static pressing slideway is the slideway that moves relatively in two connect between the face with pressure oil, will move a float case, make condition of pure liquid attrition is in between slideway face. Differ as a result of the requirement that bear the weight of, static press slideway cent to be type and shut type two kinds.

   Style is quiet the working principle that presses slideway is like graph 5-17(a) place to show. Oil pump 2 after starting, oily classics oil purifier 1 attract a person, with overflow a powerful person 3 adjust the pressure that offer oil, again via oil purifier 4, through restrictor 5 step-down come (oil pocket pressure) the oil pocket that enters slideway, go out to outflow through slideway clearance, return gasoline tank 8. Oil pocket pressure forms buoyancy athletic part 6 float have, form certain slideway clearance. When load increases, athletic component sinks, slideway clearance is reduced, fluid block increases, discharge is reduced, make oil is reduced through the pressure loss when restrictor thereby, oil pocket pressure increases, till be balanced with load W.

Graph 5-17 Static the working principle plan that presses slideway
1, 4, oil purifier; 2, oil pump; 3, overflow a powerful person; 5, restrictor; 6, athletic component; 7, fixed component; 8, gasoline tank

   Style is quiet press slideway to be able to bear only the load of perpendicular direction, bear overturn the ability of pitching moment is poor. And Bi Shijing presses slideway to be able to bear bigger overturn pitching moment, slideway stiffness is taller also, its job principle is shown like graph 5-17(b) place. When athletic component 6 be overturned after pitching moment M, the oil pocket 3, clearance of 4 increases, the oil pocket 1, clearance of 6 is reduced. As a result of each action of corresponding restrictor, make technology of oil pocket 3, numerical control

The pressure of 4 is reduced, the oil pocket 1, pressure heighten of 6, produce thereby with overturn the moment of force with contrary moment of force, make athletic component poises. In bear when load W, oil pocket 1, 4 clearance are reduced, pressure increases; Oil pocket 3, 6 clearance increase, pressure is reduced, produce thereby up force, in order to balance load W.

   Because condition of pure liquid attrition is in between slideway face, reason slideway won’t wear away, it is good that precision maintains a gender, life is long, and slideway coefficient of friction is dinky (it is 0.0005) about, power is used up little. Ply of pressure oily film suffers speed effect scarcely, oily film carrying capacity is large, stiffness is tall, suck brace up the gender is good, slideway moves smooth, do not have crawl already, also won’t produce vibration. Structure of slideway of Dan Jing pressing is complex, need to one has the hydraulic pressure unit of effect of filter of fine feel well, production cost is higher.