The hydraulic pressure of milling machine of boring of numerical control be born reachs compensation evenly
- source:NEWRGY CNC Machining
Servo a powerful person 3.
4-5 of electromagnetism reversal valve.
Fluid accuses 6-7 of one-way a powerful person.
Oil cylinder 8.
Main shaft box 9.
Before wire rope 10.
Wire rope pursues after 1 my company and French FOREST -- milling machine of boring of be born of the GIMAX200 that LINE company designs production jointly numerical control, its the motion of each axes all is used static press slideway, main shaft box drives fluctuation to move through ball guide screw, ram moves inside main shaft box, boring lever moves inside ram. To the design of the machine tool, we balance a law to balance the weight of main shaft box with hydraulic pressure, as a result of,still be opposite at the same time ram shift and assemble and unassemble the change of centre of gravity of main shaft box that accessory place causes undertakes compensating. Its principle is shown 1 times like the graph. In the graph 1 in, oil cylinder 6 connect with a travelling block, two wire rope 9, 10 bypass after travelling block, pass a pair of crown block and main shaft case respectively again 8 connection. Among them, before wire rope 9 direct solid go up on main shaft box, hind wire rope 10 pass oil cylinder 7 with connection of main shaft box. Two servo a powerful person 1, 2 charge one-way a powerful person via fluid respectively 4, 5 with oil cylinder 6, 7 UniCom. 3 for electromagnetism reversal valve, can control fluid to accuse one-way a powerful person to be opened reversely, make oil cylinder answers oil. Among them, the journey of 6 gives priority to oil cylinder the half of next athletic travels on axle box, double the pressure on its piston is weight of main shaft box. In this balance system, the weight of main shaft box is by around two wire rope 9, 10 assume jointly. We can reach the gravity of main shaft box roughly the pulling force of around wire rope to regard a counterbalance is (will static press slideway and force of attrition of ball guide screw to ignor) . When the cutting tool that carries an installation when ram or accessory are changed, or when ram is mobile inside main shaft box, the centre of gravity of main shaft box will produce change, original counterbalance department will be destroyed. To form new counterbalance department, need the tensile reapportion to two wire rope. This " the task " basically be by the graph 1 medium two servoes a powerful person is finished. Below introduce a powerful person or family of these two servo simply. Servo a powerful person 1, 2 be two duplex a powerful person, interior reachs pressure sensor of positional sensor, adjust discharge and pressure accurately. Its job process sees a picture 2. Should put through with switch 1, 2 when, can realize flow control. Positional sensor detects position of core of a powerful person, express with voltage signal UL1, classics comparator and UQS of instruction voltage signal undertake comparative, compare result Δ U to stock positional controller. Positional controller controls shift of core of a powerful person through changing electric current of priority valve coil, get the flow of a need. Right now, feedback voltage UL1 is equal to instruction voltage UQS. In controlling a process here, the position of core of a powerful person and instruction voltage size become direct ratio. When instruction voltage polarity is changed, way of movement of core of a powerful person also is changed subsequently. Graph 2 put through when switch 1, 3 when, can realize pressure control. Pressure sensor detects A mouth (PL of graph 1) pressure, express with voltage signal UP1. After UP1 and UP2 of instruction voltage signal are compared, the result inputs pressure controller. If both unequal, criterion the signal of displacement of core of a powerful person of change of pressure controller output, change discharge thereby and realize the control to pressure finally. In controlling a process here, the value of PL1 of A mouth pressure and instruction voltage UPS becomes direct ratio. In the graph 1 in, servo a powerful person 1 it is to use control oil cylinder of 6. Oil cylinder the weight that the action of 6 is component of box of balance main shaft. When the speed that moves up and down when main shaft box is changed, we can lose servo a powerful person through the change the UQS of instruction voltage signal of 1, will adjust accordingly oil cylinder the discharge of 6 inputs or output. When the cutting tool that when ram the installation that carry a department differs or accessory, component of box of whole main shaft (include to pack the cutting tool that carries a department in ram or accessory) weight will produce change. Right now, can lose servo a powerful person through the change the UPS of instruction voltage signal of 1 will change supply oil cylinder the pressure of the hydraulic pressure oil of 6, make component of winner axle box still can poise thereby. Servo a powerful person 2 control oil cylinder 7. Oil cylinder the influence that because the place of change of centre of gravity of component of main shaft box is brought,the action of 7 is compensation. For example, when ram is extended outwards, as a result of the reach of centre of gravity of main shaft box, original counterbalance department got destroy, relative to original balance the position produced moment of an add capsize, make pitch of main shaft casing, wire rope tension increases before, wire rope tension is reduced after. At this moment, can carry servo a powerful person 2 reduce supply oil cylinder the force of hydraulic pressure oil pressure of 7, change the tension of around wire rope, drop the capsize moment of force of because of be being extended outside ram generation evenly, make main shaft box is in balance position from beginning to end. In servo a powerful person 1, 2 in, the feedback value that measures through pressure sensor place is mouth of A of servo a powerful person only (the pressure of graph 1) , this pressure and oil cylinder 6, the poor value with 7 medium pressure fair existence. This poor value basically is the pressure loss when hydraulic pressure oil sheds the conduit between classics servo a powerful person and oil cylinder and fluid to charge one-way a powerful person. The conduit between servo a powerful person and oil cylinder is longer, pressure loss will be bigger. Accordingly, answer to approach servo valve oil cylinder installation as far as possible when assemble, the fluid with choice lesser at the same time open pressure charges one-way a powerful person, in order to reduce the effect that pressure loss place causes. Because boring lever is relatively fine (GIMAX200 boring shank diameter is 200mm) , when because this is become,boring lever is extended, must consider its influence of self-prossessed bending metabolic, how compensating this to be out of shape again is a very serious problem. GIMAX200 solves this problem through compensation method of Y axis displacement. Every extend boring lever to be apart from certainly, main shaft box go up move, make thereby ministry of boring lever end can maintain in academic position. In afore-mentioned balance and compensation process, after be being calculated according to academic position, the voltage signal that loses servo a powerful person and flagging to boring lever compensation input numerical control system. In debugging a process actually, as a result of all sorts of elements (for example ambient conditions) influence, some precision are likely short of requirement. At this moment, need the sag of chain when according to ram and boring lever every extend certain distance, computation gives compensation to be worth, to afore-mentioned control the process undertakes compensating. Through afore-mentioned balance and compensation, GIMAX200 is examining finally when geometrical precision, a few precision that concern with this were achieved perfectly level. Among them, when ram is extended (the journey is 1250mm) , the linearity inside perpendicular plane is 0.
025mm/1250mm, the parallelism with horizontal datum plane is 0.
03mm/1250mm; And when boring lever is extended (the journey also is 1250mm) , the linearity inside perpendicular plane is 0.
03mm/1250mm, the parallelism with horizontal datum plane is 0.