Monitoring of CNC machine tools by AE sensor . The Machine Tool monitoring system is a flow of information and processing systems where information selection, data acquisition, information processing and decision making on integrated information are integrated. The purpose of monitoring the condition of the appliance is to detect the beginning of interference in the machining and wear process of machine tool components. Appliance conditions have been extensively studied in the past and have focused on the detection of sculptural wear, tool breakdown and residual tool life estimation. It is important to identify the condition of the equipment on-line in the machining process to improve productivity, better quality of parts and lower costs for unmanned automatic manufacturing systems.
Video CNC machine tool monitoring by AE sensors
Machine tool monitoring techniques
Monitoring of machine tools can be done with or without additional sensors.
By using additional sensors, monitoring can be done by measuring:
- cutting style (with multi-channel table dynamometer or rotating dynamometer)
- vibration amplitude using multi-channel accelerometer
- sounds that can be heard from the machining process
- high frequency sound or acoustic emissions
Monitoring of the sensorless machine tool is done by measuring internal drive signals such as:
- give the motor current
- spindle motor current
- spindle strength
The combined measurements of some quantities are also possible.
Maps CNC machine tool monitoring by AE sensors
Acoustic emission sensor
Machine tool monitoring is explained by Acoustic Emission (AE) sensor. The AE sensor is usually defined as the sound emitted as an elastic wave by solids when it is deformed or struck, caused by the rapid release of localized stress energy. Therefore, this is an event phenomenon that releases the elastic energy into the material, which then radiates as an elastic wave. Acoustic emission frequency detection range from 1 kHz to 1 MHz. Rapid voltage events produce a voltage wave spectrum ranging from 0 Hz and typically fall at several MHz. AE can be associated with an irreversible energy release. It can also be generated from sources that do not involve material failures including friction, cavitation and impact. The three main applications of the AE sensor phenomenon are: a) Source location - determining the event location of an event b) Material mechanical performance - evaluating and characterizing materials/structures; and c Health monitoring - monitor safety operations.
How AE sensors monitor machine tools
The acoustic sensor (AE) works based on the principle of measuring the high frequency energy signals generated during the cutting process. It also measures the AE energy that results from fracture when the tool is damaged. It is suitable for applications where low AE background signal level is compared with sound damage tool. This makes the AE sensor ideal for detecting damage to small exercises and taps. It's easy to install on new and existing machines. The AE sensor detects the signal strength of the proportional monitoring even in machining operations, which results in very small cutting forces. In combination with true strength, it improves the reliability of damage monitoring. These are used mainly with solid carbide tools, or very small tools on large and multi spindle machines. Most sensors must be attached to the machine tool surface. However, there is an alternative method of AE wave transmission. The rotating AE wireless sensor consists of a rotating sensor and a fixed receiver. The AE sensor can also receive acoustic waves through the cooling lubricant jets, which can be connected directly to the appliance or workpiece.
Machine tool monitoring systems generally use sensors to measure cut style components or amounts associated with cutting forces (power, torque, distance/displacement, and strain). The AE sensor is relatively easy to install in existing or new machines, and does not affect the integrity and rigidity of the engine. All system suppliers also use acoustic emission sensors, especially for monitoring small appliances and for grinding. All sensors used in machine tool monitoring systems are well suited for rough machine tool environments. The difficulty in designing a reliable tool monitoring tool can be attributed to the complexity of the machining process itself, which may have one or more of the following characteristics, regardless of the change of the machine tool itself.
References
Source of the article : Wikipedia
0 Comments