On-line detection, also known as real-time detection, is a detection method that detects the tool in real time during the machining of the workpiece in the CNC machining center and makes corresponding processing according to the detection result. Online detection is a detection technology based on computer automatic control, and the detection process is controlled by a numerical control program. Let’s take a look at it.
First, the composition of the online processing system of CNC machining center
Simply put, the CNC machining center online inspection system consists of software and hardware. Similar to CNC machining system, its hardware part is usually composed of machine tool equipment, numerical control system, servo system, probe system and computer aided system; the software part uses secondary development technology to realize online measurement programming similar to CNC machining programming. Get the CNC code that drives the CNC machining center to measure.
1, machine tool equipment
The machine tool equipment is the basis for realizing the machining and inspection of the workpiece. The working component is the component that realizes the basic motion required. The positioning accuracy of the feed transmission component directly affects the final machining accuracy and detection accuracy of the workpiece.
2, servo control system
The servo control system is an important part of the CNC machining center. It is used to realize high-precision feeding and positioning of the machine. The device can realize multi-axis linkage machining under the control of CNC numerical control system, and realize complex curved surface and profiled contour surface workpiece. machining. The performance of the servo control system is the main factor determining the machining accuracy, measurement accuracy and surface quality of the machine.
3, CNC system
The CNC system is the standard configuration of the CNC machining center. Its main features are input storage, CNC machining, interpolation calculation and various control functions of the machine tool. All of them are realized by executing the machining program of the workpiece under the control of the device. The CNC system generally consists of a central processing memory and an input and output interface. The central processing unit is composed of a memory, an arithmetic unit, a controller and a bus.
4, the probe system
Simply speaking, the measurement system consists of a touch-trigger probe, a signal transmission system and a data acquisition system. It is a key part of the on-line detection system of the CNC machining center, which directly affects the accuracy of online detection. The key component is the probe. The probe can be used to measure the dimension during the machining process. The size compensation is automatically performed according to the measurement result, thus improving the machining accuracy of the workpiece.
Second, the working principle of the online processing system of CNC machining center
The key component of the online detection system that directly affects the detection accuracy is the probe part. The most commonly used is the touch probe with search forward capability. One of the most critical functions of the probe system is the ability to generate a program interrupt command. When the probe end is in contact with the workpiece being tested, the probe system sends an external interrupt request to the CNC CNC system.
When the CNC machining center control system receives the interrupt signal, it uses the positioning system to latch the coordinate value of the center of the measuring end, thereby determining the coordinate value of the contact point between the measuring end and the measured workpiece. Thereby the size compensation is performed.