Application Case - Delta Electronics

Application Case
Industrial Automation BU, Delta Electronics, Inc.
Case
Application of Delta’s AC Servo Drive in Electric Discharge Machine
Issued by
Applicable to
Solution Center
Date
November, 2009
Pages
3
ASDA-A2 series AC servo motors and drives
Introduction
The concept of Electric Discharge Machining (EDM) is to use electrical energy to generate electrical discharges
(sparks) and enable the workpiece to be melted rapidly. In other words, it is a kind of manufacturing process where the
material is removed by generating high voltage sparks through a small gap filled with a dielectric fluid. A more detailed
description is that in electric discharge machine, a difference of potential is applied between the two electrodes, one is
called electrode (tool) and the other is called workpiece. To discharge a high voltage between electrode (tool) and work
piece, the dielectric breaks and therefore the current flows between the two electrodes and makes a melt on the border
of the surfaces of the electrode (tool) and work piece. This technique is used to form complicated shapes regardless of
the hardness of the workpiece as long as the workpiece (materials) are conductive. Nevertheless, a necessary condition
for achieving a good surface finish is the most important application challenges in the process of the electric discharge
machining.
The customer in this application case is a well-known precision machinery manufacturer in Taichung, Taiwan, mainly
manufacture CNC electric discharge machine and wire cutting machine.
Function
This machine is used to cut or form various kinds of metal materials. The electrode is utilized to process different
shapes of workpiece, suitable for rapidly manufacture small quantity but various molds.
This manufacturer (Delta’s customer) used general stepping motor to control each axis of the machine previously and
could not meet their customer’s needs. When the machine operates in high speed, the response performance of the
motor is not good. When the machine operates in low speed, the processing operation is not smooth and cause the
surface finish is not well so the product quality is uncertain and goes down.
System Structure
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EXCELLENT
Application Case
Industrial Automation BU, Delta Electronics, Inc.
Solution
1.
Processing requirements:
ƒ
ƒ
ƒ
2.
Max. speed is 2,000RPM
Applicable wire diameter is 0.1 ~ 0.2mm
Good surface finish is required
During the processing operation of the machine, it is essential to send the commands given by the host (external)
controller to the servo drive quickly and accurately and drive the servo motor to move to the correct position and
complete processing operation. In the meanwhile, it is also necessary to feedback the current status in real time in
the process of manufacturing and accomplish the processing operation completely and rapidly. To satisfy these
requirements, we recommended the customer to adopt Delta ASDA-A2 series servo motors and drives. ASDA-A2
series servo drives are provided with high-speed calculation and precise feedback control function incorporating dual
CPU (DSP and CPLD) technology and intended to drive ECMA series servo motors to achieve precise positioning even
at low speed. In addition, ECMA series servo motors are equipped with 20-bit resolution encoder which offers better
position and speed control ability, and less noise during operation, especially at low speed so that the processing
operation is more smooth with better performance. Besides, ASDA-A2 series servo drives features up to 1kHz
frequency response characteristic which can enhance the tuning efficiency and enable the response of the position
and speed command to be more real-time. Other additional functionality, such as auto-tuning function, auto
resonance suppression function, low-pass filter for smoothing command and user-friendly software interface and
high-speed PC monitoring function (similar to a digital oscilloscope), etc. all maximize the performance of ASDA-A2
series and improve ASDA-A2 series to be more advanced, more rapid, more precise and more stable so as to fulfill
the requirements of high performance, high response, high precision and high reliability.
System Configuration
1.
X-axis servo drive and motor: ASDA-A20421-B, ECMA-C10604ES
2.
Y-axis servo drive and motor: ASDA-A20421-B, ECMA-C10604ES
3.
Z-axis servo drive and motor: ASDA-A20721-B, ECMA-C10807ES
Features of ASDA-A2 series servo drive:
1.
20-bit resolution encoder is equipped with to offer better position and speed control ability, and less noise during
operation, especially at low speed which is suitable for the applications of CNC electric discharge machine and wire
cutting machine.
2.
8 digital inputs and 5 digital outputs are selectable and all can be user-defined via parameters.
3.
Frequency response characteristic is up to 1kHz. The positioning is more stable and the response is more rapid.
4.
2 auto notch filters and 1 manual notch filter are provided to suppress the mechanical resonance more effectively.
5.
High-speed PC monitoring function (similar to a digital oscilloscope, max. scan frequency is 16K) is available, capable
of offering real-time and accurate information for the customer.
6.
Built-in excellent motion control functions which include E-CAM, Capture, Compare and Pr mode, etc. greatly
increase the ability of motion control and enhance the reliability of the system.
品質至上
信賴第一
追求卓越
QUALITY
RELIABLITY
EXCELLENT
Application Case
Industrial Automation BU, Delta Electronics, Inc.
More information on Delta’s ASDA-A2 series servo motors and drives, visit our website at
http://www.delta.com.tw/product/em/motion/motion_servo/motion_servo_product.asp?pid=2&cid=1&itid=5
品質至上
信賴第一
追求卓越
QUALITY
RELIABLITY
EXCELLENT