Feed of numerical control machine tool sends the application that uses mechanical part

  • Time:
  • Click:152
  • source:SHNMIN CNC Machining
Normally, a system of typical feed of closed-loop control of numerical control machine tool, compare by the position, enlarge component, driving unit, mechanical gearing and detect the composition of a few parts such as feedback component. Among them, mechanical gearing is one of positional control important segment. The mechanical gearing that says here, it is to show the whirligig drive source turns into the catenary of whole and mechanical drive of the sharp movement of workbench, include nut of gear plant, guide screw deputy wait for intermediate main transfer machinery. One, shaft coupling shaft coupling is a kind of returns move to pass torque and motion together unit that two rods that use join to send an orgnaization make. The type of shaft coupling is at present various, have hydraulic type, electromagnetism type and mechanical. The application of mechanical shaft coupling is most wide. Sleeve shaft coupling is tectonic and simple, radial size is small, but it is difficult to assemble and unassemble (the axis needs axial to move) . And in asking two axes are opposite strictly, not radial of be patient of or angle deviation, because of when this is used, be restricted certainly. Circuitous shaft coupling uses cone-shaped clamp ring to deliver load, can make motivation is delivered without directional clearance. Flange type shaft coupling is tectonic of simple, cost, can deliver bigger torque, commonly used at rotate speed low, 5 kinds are reached, axial tigidity reachs good to neuter situation greatly. His main drawback is pair of two axes is very tall to neuter requirement. If exist between two axes displacement and tilt, save add load is caused inside parts, make working state exasperate. 2, decelerate orgnaization (1) positive drive of positive drive device is a kind of mechanical drive with very wide application, there is positive drive almost in the gearing of all sorts of machine tools. The end that uses positive drive device in system of feed of servo of numerical control machine tool has two. The servo electric machinery of the torsion that is will high rotate speed (if the pace enters electric machinery, dc and communication servo electric machinery to wait) the execution that outputs a change to be big torsion of low rotate speed input; Another it is to make the moment of inertia of ball guide screw and workbench has lesser proportion in systematic technical secondary school. In addition, still can assure the athletic precision of a requirement to open loop system. Accuse a machine tool to machine the influence of precision to reduce logarithm of tine side clearance as far as possible, often take step on the structure, with reduce or removing gear error of deputy light locomotive trip. If use double a law of gear fault tine, use prejudicial set adjust gear to deputy center is apart from or use axial spacer setting method to eliminate gear backlash. With use synchronous tooth form to take photograph comparing, gear decelerate device is used in catenary of drive of feed of numerical control machine tool, produce low frequency vibration more easily, because middling of this decelerate orgnaization configures damper,will improve dynamic performance. (2) synchronous tooth form takes synchronous tooth form to take drive is a kind of new-style belt transmission. As ordinal as the teeth of a cogwheel of belt annulus clench the teeth delivers the tooth form that he uses tooth form to take motion and motivation, hold the advantage that takes positive drive and transmission, catenary drive concurrently consequently, and without relatively slip, average transmission is more accurate, transmission precision is tall, and the strength that tooth form brings tall, ply small, weight light, reason is usable at high speed drive. Tooth form is taken need not special Zhang Jin, reason action is mixed in the axis the load on bearing is small, transmission efficiency is tall also, show wide on numerical control machine tool already application. The main number that synchronous tooth form brings and norms are as follows: Pitch pitch P is photograph adjacent two tine are apart from in section on-line. Spend when the job as a result of puissant layer changeless, the section line that so the central line of puissant layer is taken for tooth form by the regulation (neutral line) , regard tooth form as the nominal length of the belt with the circumference L of section line. Modulus modulus definition is M=p/ π , make tooth form takes dimension calculative a main basis. The other parameter that other parameter tooth form takes and dimension and involute rack are basic and identical. Tooth form takes dentiform computation formula and involute rack to differ, because the section line of tooth form belt is on puissant layer, and be absent tooth depth is mid. The tagging that tooth form takes the method is: Tine of × of modulus × width is counted, namely Z of × of M × B. 3, nut of ball guide screw deputy to improve the sensitivity of feed system, fixed position precision is mixed prevent crawl, the attrition that must reduce system of feed of numerical control machine tool reduces the difference of coefficient of static, kinetic friction. Accordingly, form not quite long sharp movement orgnaization guide screw of commonly used ball deputy. Deputy transmission efficiency is as high as ball guide screw 85%-98% , it is common and slip guide screw deputy 2-4 times. Deputy angle of friction is less than ball guide screw 1 ° , because this is not locked up oneself. If deputy drive of ball guide screw rises,fall motion (be like main shaft box or lifting platform litre fall) , must have unit of apply the brake. The coefficient of static, kinetic friction of ball guide screw does not have what difference almost actually. It can eliminate backlash and bring to bear on preload, conduce to raise fixed position precision and stiffness. Ball guide screw is made by special workshop. CNC Milling CNC Machining