Project background
Customer company: a large-scale manufacturing enterprise in a country;
Industry: high-end equipment manufacturing industry, heavy machinery processing;
Application scenario: precision testing of large-scale boring and milling machining centers.
The company has a large boring and milling machining center for processing large equipment parts. The machine tool completes milling, drilling, boring and other processes at the same time. In order to ensure the accuracy and product quality of its processed parts, it is necessary to test the size accuracy of parts online and offline.
Challenges and pain points of customers
1 Oversized measurement: parts can be up to 5 meters long, and the traditional three-coordinates cannot meet the online size control of parts and the measurement needs of large dimensions (such as axiality, parallelism, etc.);
2 Online testing: Testing is not only to verify the accuracy of the machine tool, but also to quickly locate the source of the error, clarify the status of the parts, and finally ensure the accuracy and size of the parts after it is off-line;
3 Complexity of workshop environment: There are interference factors such as vibration and temperature fluctuations in the workshop, which poses a challenge to high-precision measurement.
Solution
After comprehensive evaluation, the customer enterprise chose to use the API brand Radian Core laser tracker measurement system as the solution.
1 Core equipment: Radian Core laser tracker - Radian Core laser tracker has a micron-level measurement accuracy (μm, 1/1000mm) and a measurement radius of up to 80 meters, which can meet the needs of large machine tool testing;
2 High-precision target ball (SMR): used to realize contact measurement data collection with laser tracker and reflect laser beam;
3 Portable control unit and measurement software: used to control the tracker, collect data, and automatically generate analysis reports.\
Figure 1: API brand series laser tracker (from left to right model: iLT / Radian Plus / Radian Pro / Radian Core / iLTx)
Implementation plan
First, carry out inspection planning and equipment layout: according to the size of the parts to be tested, place the laser tracker in a position where you can see the stroke of each axis. Radian Core laser tracker is portable (equipment weight <11kg) and can be quickly deployed at assembly sites or workshop sites.
Then, the on-site measurement can begin. When measuring, the operator holds the target ball with a built-in prism, and the laser tracker shoots the laser to the center of the target ball and locks the tracking. After the target ball fits and stabilizes with the position to be tested, the tracker quickly collects the three-dimensional data of the position at a rate of 1000 points/second and transmits it to the measurement software storage located on the laptop terminal. It is used for subsequent data analysis; in measuring AGV, machine tools, robots and other scenarios, the target ball can also be fixed on the AGV platform, the spindle position of the machine tool, or the end of the robot, which can realize automated data measurement and collection according to demand.
Select a reasonable tracker station for the measurement needs of parts and measure the size of the shaft hole. Through the reasonable arrangement of the transfer station, the movement of the tracker station is realized, which not only ensures the accuracy of the station, but also stitches the detected data together. Through the temperature compensation system of the software, the trouble of parts not having to wait for constant temperature measurement is realized.
Figure 2: API laser tracker measurement site
Data analysis and report generation
In this case, the operator uses Polyworks measurement software to automatically analyze the technical requirements of the parts required by customers, such as the diameter size of each hole, the coaxiality size, and the relative position ruler, according to the collected spatial coordinate data. The software automatically generates intuitive analysis reports (including data lists, curve charts, error cloud charts, etc.).
In addition to the Polyworks measurement software used in this case, the API brand series laser tracker (Radian and iLT) can also be compatible with the vast majority of measurement software on the market (including but not limited to: SpatialAnalyzer, Verisurf, Metr Olog, etc.), can be quickly integrated into the customer's existing measurement system.
In addition, API has accumulated nearly 40 years of technology, went deep into the field, combined with the needs and habits of front-line use, and independently developed the MeasurePro series of measurement software, which can quickly integrate the full series of API measurement equipment, realize multi-equipment and multi-link data collection and analysis, and provide customers with precision Measure the new experience of excellence.
Achievements and benefits
After the introduction of the API Radian Core laser tracker system, customer enterprises have achieved remarkable results in the detection and maintenance of large machine tools.
1 The inspection efficiency has been greatly improved: Compared with the traditional testing method, the inspection efficiency has been shortened by more than 70%. In the past, it took 1-2 days to complete the precision inspection of parts, but now it only takes half an hour to complete, which greatly reduces the downtime of the machine tool;
2 High detection accuracy and reliability: The laser tracker provides micron-level measurement accuracy, and its built-in temperature compensation module can effectively offset the impact of environmental temperature changes in the workshop on the measurement results, ensuring the accuracy and reliability of the detection data;
3 Accurate guidance: The automatically generated detailed inspection report can not only accurately reflect the current precision status of the parts, but also preliminarily determine the processing status of the machine tool and compensate for the processing parameters.
Conclusion and Prospect
This case shows that the high-precision laser tracker is a rational tool to solve the problems of accuracy and efficiency in the inspection of large machine tools and ultra-large workpiece manufacturing parts. It can not only replace a variety of traditional testing tools and realize fast and accurate multi-dimensional measurement, but also provide accurate guidance for equipment maintenance through intuitive data analysis. It is an important part of mechanical processing enterprises' move towards digital and intelligent quality management.
In the future, with the progress of technology, the integration of laser tracker and machine tool control system will be closer, which is expected to realize real-time error compensation and closed-loop control in the processing process, and further promote the development of the mechanical processing industry towards ultra-high precision and intelligence.