In-Machine Measurement and Intelligent Modification Technology

In-Machine Measurement and Intelligent
Modification Technology

Principle

In the high precision machining, many factors lead to the accuracy out of tolerance or worse surface quality, such as spindle growth and 5-axis machine origin floating caused by thermal fluctuation, cutting tool profile error, cutting tool abnormal wear.

The In-machine measurement technology is developed by Beijing Jingdiao Group, which is a complete solution integrating CAD/CAM technology and CNC machining technology.

Firstly, the intelligent NC program is generated by Jingdiao SurfMill software, including machining program, tool measurement program and workpiece measurement program.

Secondly, the NC runs on the machining center with Jingdiao CNC System. During the process of machining, the workpiece and tool are measured by sensors. Then the results are analyzed by the CNC system with built-in algorithm. Error will be corrected and compensated by CNC system automatically (e.g. workpiece center drift, tool wear, etc.) to achieve accurate machining process.

With the application of In-machine measurement technology, Beijing Jingdiao High-speed machining center can control various errors in product processing and optimize the downstream processing in real time. This technology can maximize the performance of machine tools, improve the machining accuracy of workpiece, and provide comprehensive support for the products of enterprise.

Advantages

The machine tool performance is fully utilized. The measurement uncertainty < 2μm, and 2σ < 0.5μm.

The measurement and correction of workpiece position before machining are widely used, especially in 5-axis machining.

Machining and measurement are carried out in one machine, reducing auxiliary time and process flow.

The tool diameter, length and 3D profile are measured during machining to realize the high accuracy of machining.

The measuring processes are programmed in Jingdiao CAM software, and automatically performed by Jingdiao CNC system and machine, making it easy for users.

Disadvantages

Occupy some cycle time. In-machine Measurement time is required, while CMM time will be saved.

To apply the technology, the guarantee conditions are relatively strict, for example, the product surfaces need to keep clean. Scrap and dirt can affect the accuracy of measurements.

The measurement toolpath can only be programmed in Jingdiao CAD/CAM software, SurfMill and only run in Jingdiao CNC system. CNC systems from other brands are not supported.

Production constraints and limits

3D surface can be measured accurately and directly.

The measurement uncertainty < 2μm, and 2σ < 0.5μm, so comparison measurement is accepted for high-accuracy measuring.

Various structure of workpiece can be measured. The stylus of probe, such as spherical structure/cylindrical structure/ T-Shaped structure are all supported.

Multiple stylus structure of probe can be mounted in one machine to measure different structure.

Only contact measurement is supported. When measuring soft materials such as copper, scratches may appear on the workpiece.

The styli size determines the structure which can be measured. The minimum space can be measured is 1.5mm. The maximum length of styli can be used is 200mm, but 5-axis machine can measure in different direction to achieve more deep structure.

The measurement accuracy depends on the precision of machine. To ensure the accuracy of measurement, a periodic calibration process is necessary.

Large size workpiece needs more measuring time.

Cost

The cost includes the following two parts, one is the hardware cost, such as probe, receiver, standard ring or standard ball. The cost is related to the desired precision. The other is the software cost, only Jingdiao CAM software and CNC systems with measuring function and authority can use this technology, additional cost may apply for professional measurement function.