AC servo motor in Electronic Tensile Testing Machine
Electronic tensile testing machine is mainly used for tensile compression and bending test of plastic sheet, pipe, profile, plastic film and rubber, wire and cable, waterproof coiled material, metal wire, etc. It is an industry and mining, commodity inspection arbitration, research institute, college Institutions, engineering quality supervision stations and other departments ideal testing equipment.
Through the great efforts and cooperation with our customers in this application, currently ECON TECH's AC servo system has been successfully applied in this type of equipment. Now we have included some problems and experiences encountered in the application process as follows:
1 This device uses the econ tech’s EC-90M075D motor with ECN-GA2307B driver. The motor is connected with 1:30 planetary gear box. The driver works in position mode. The electronic gear ratio is 375 pulses per week, and the pulse output is used. The frequency ratio is 1. Equipment test speed is 0.5mm/min-500mm/min.
2 This type of equipment control is generally developed by the manufacturer using a single-chip microcomputer. The tension driving part adopts an AC servo motor acceleration and deceleration gear, and a synchronous belt drives a pulling arm to move up and down. The control requires a relatively high requirement for the motor and needs normal operation. The motor runs at extremely low speeds. When the work is completed, the motor is required to return to the starting point at a speed of 4,000 rpm. Such special requirements for the adjustment of the servo parameters are not the same as usual, because the conventional parameter motor is less than 4,000 rpm, then the internal maximum speed needs to be released and adjusted to 4000 rpm, and at the same time, the motor runs at 4000. The position of the revolution/minute is followed by a large error, so the positional overshoot parameter is adjusted to adapt to this high speed operation.
3 The actual displacement of the tension arm is calculated by the number of pulses output by the encoder of the servo, and the single-pulse count used for the upper counting is due to the fact that the servo motor has been dynamically adjusted from the microscopic point of view and microscopically has a slight swing phenomenon. This will cause inaccuracy of the count. The lower the speed, the more inaccurate the phenomenon becomes. The standard servo is difficult to guarantee the accuracy of the counting. After understanding the actual needs of the customer, we do some processing on the driver pulse output software. Automatic phase detection is set. When the servo motor oscillates within a certain range, there is no pulse output. When the error is exceeded, the pulse is output. Although there are several pulse errors at the beginning of the operation, it does not affect the count. Accuracy, and these pulses do not accumulate.
4 As the principle of servo control determines the external disturbance of the servo, and the control part of this device is a single-chip microcomputer system, it is necessary to focus on how to solve the interference problem on the line, and it is necessary to add some measures to suppress the interference, such as the power of the motor. The trace should be far away from the control part of the SCM, and the equipment should be well grounded. The isolation of the control power supply of the SCM should be to isolate the transformer or filter to suppress the entrance of high-frequency interference signals.
Through the above improvement measures, ECON TECH'S servo has been widely applied in the electronic tensile testing machine. At the same time, it also fully reflects our company as a company with its own core development technology according to the customer's actual needs. And on-site requirements for some product adjustments, greatly facilitate the use of customers, get customers recognized!