One, does overview feed servo comprise: ? of ⒒ of deceive of pa of of of of Europe of ⑺ of two of Bian of of of the that hurt Europe swings coerce of green of crime pa of to study effect of main transfer machinery of machinery of actuating device of servo of circuit of drive of servo of? of mallet umbrella is: Receive the feed rate that numerical control system issues and displacement command signal, after making changeover and enlarge by servo drive circuit, classics servo actuating device (electric machinery of servo of dc, communication, power pace enters electric machinery, electro-hydraulic pulse motor) with mechanical main transfer machinery, head of the workbench of drive machine tool, main shaft is worn wait for executive component to realize working feed and rapid movement. The feed system of the feed servo of numerical control machine tool and common machine tool has substantially difference, it can dominate the athletic speed of executive component and niche accurately according to command signal, and a few executive components press contrail of motion of complex of place of definite pattern motion. All sorts of electric machinery: Servo of numerical control feed is pressed have detect without the position and feedback undertakes classified, have the following two kinds. 1. 4-30 of graph of open loop servo is graph of principle of open loop servo, it waits for composition into electric machinery and its drive circuitry by the pace. Its function is every input an instruction pulse, the pace rotates into electric machinery proper point of view, the pace is spent into the rotate speed coming back of electric machinery depend on the frequency of instruction pulse. The size of corner counts a decision by instruction pulse. The precision of open loop system is poorer, but because the structure is simple, adjust easily, in precision more extensive application 2 still gets in not quite tall circumstance. Does closed circuit servo comprise: ? Vinegar of Jin of of of K of umbrella of branny swollen mallet makes an appointment with alkyne of small car of sheng of glutinous of of Europe of ⑺ of two of Bian of department of Ran of ⒈ of deceive of pa of Hu of ⒓ of of black of of injury Europe aning enclosure for storing grain of Mao of admire of department of Ran of impaludism of lotus root of plutonium of Ga of leg of Pang of lotus root of ⌒ of clumsy of Mu of Mei of Hu pa aning enclosure for storing grain, its detect feedback signal is obtained from axis of servo electric machinery or ball guide screw. To high accuracy or large machine tool, go up in the mobile component such as workbench from installation directly detect feedback signal is obtained in device. For distinction both, former say for system of half closed circuit. The displacement that measures the mobile part such as workbench directly through closed circuit system realizes the feedback control with tall precision thereby. But the price of this kind of measurement unit is higher, installation and adjust more complex and maintain not easily. Under photograph comparing, the corner in system of half closed circuit measures easier implementation, but as a result of succeed drive catenary the influence of transmission error, measure compensation precision to compare difference of closed circuit system. System of half closed circuit because system simple and adjust convenient, already applied on numerical control machine tool widely now. How to choose servo drive system, in actual in must decide according to the requirement of the machine tool. The treatment job that place of all sorts of numerical control machine tool finish is different, they are so endless also to the requirement of feed drive identical, but can generalize roughly for the following respects: (1) precision asks servo must assure the fixed position precision of the machine tool and treatment precision. To cheap model numerical control system, drive control precision is commonly 0. 01mm; And to system of high-powered numerical control, drive controls precision to be M of 1 μ , it is even 0.
M of 1 μ . (2) answers speed to machine exterior surface roughness lowly to make sure precision of outline cutting appearance is mixed, besides asking to have taller fixed position precision, have even answer character goodly quickly, ask to dog namely the response of command signal wants fast. (Scope of timing of 3) timing scope is the top rotate speed that shows manufacturing machinery asks electric function is offerred, with lowermost rotate speed than. Normally (4-22) is in all sorts of numerical control machine tools, because treatment uses cutting tool, be pledged by treatment material and what spare parts treatment asks is different, to make sure the for love or money can obtain optimal cutting condition, must have with respect to system of requirement feed drive enough wide timing range. (The treatment of 4) low speed, big torsion according to the machine tool characteristic, often have heavy cut below low speed, issue feed drive system to must have big torsion output in low speed namely CNC Milling