Numerical control machining on-machine measuring system

Abstract

The invention discloses a numerical control machining on-machine measuring system which comprises a grating ruler body, a laser displacement sensor and a circular grating encoder, the grating ruler body and the laser displacement sensor collect axial contour data, and the laser displacement sensor and the circular grating encoder collect radial contour data. The data is transmitted to the data acquisition card in a unified mode and then sent to the upper computer for processing, the laser displacement sensor is installed on a machine tool body through a vertical support and protected by a protective cover controlled by a steering engine to prevent the sensor from being damaged by cutting scrap iron, and the grating ruler reading head is used for detecting the axial displacement of a cutter. The circular grating encoder is used for detecting spindle rotating speed and workpiece roundness. The device has the advantages of being high in real-time performance, high in measurement precision, stable in structure and the like, and is suitable for the effects of on-machine measurement and contour monitoring in the numerical control machining process.

Description

Technical Field

[0001] This application relates to the field of in - machine measurement systems, and particularly to a numerical control machining in - machine measurement system. Background Art

[0002] With the continuous development of the manufacturing industry towards high precision, high efficiency, and intelligence, numerical control machining technology has been widely applied in high - end manufacturing fields such as aerospace, automotive manufacturing, and precision molds. During the numerical control machining process, the dimensional accuracy and geometric tolerance of workpieces directly affect the quality and performance of products. Traditional dimensional inspections mostly adopt off - line measurement methods after machining, such as using tools like coordinate measuring machines, projectors, calipers, or micrometers. Such methods have deficiencies such as low measurement efficiency, detection lag, and large workpiece transfer errors, and are difficult to meet the requirements of modern manufacturing for high - efficiency, high - precision, and real - time quality control.

[0003] For this reason, the "in - machine measurement" technology has emerged. So - called in - machine measurement refers to directly performing real - time detection of the dimensions and profiles of workpieces during or after machining without unloading the workpiece, using measuring devices installed on the machine tool. Compared with traditional off - line measurement, in - machine measurement has advantages such as time saving, reduction of human error, and improvement of detection efficiency, and is a key link in realizing digital manufacturing and intelligent workshops. Currently, the main application methods of in - machine measurement technology include contact probes, photoelectric probes, laser displacement sensors, etc.

[0004] Regarding the above - mentioned related technologies, the inventor believes that there are the following technical defects: Existing in - machine measurement systems still face some key technical bottlenecks: First, the measurement dimension is limited. Most systems only support single - direction or single - dimension detection and cannot simultaneously obtain axial and radial profiles. Second, the anti - interference ability of the system is insufficient. Factors such as metal chips, coolant splashing, and vibration are common in the machining environment, which can easily affect the accuracy of sensors and even damage their structures. Third, the processing speed of measurement results and data transmission is slow, making it difficult to support closed - loop control feedback in the high - speed machining state. Fourth, the system integration degree is not high, and the compatibility with machine tools, upper computers, and control systems is poor, affecting application promotion and operation convenience.

[0005] Therefore, there is an urgent need to design a numerical control machining in - machine measurement system with perfect functions, high integration, high measurement accuracy, and strong anti - interference ability. This system should be able to work stably in a complex machining environment, collect real - time profile information of the workpiece in the axial and radial directions, and achieve seamless interaction with the upper computer through high - speed data transmission, providing timely and reliable detection and feedback basis for the numerical control machining process. Summary of the Invention

[0006] In order to improve the technical problems of low integration and functionality of the in - machine measurement system, this application provides a numerical control machining in - machine measurement system.

[0007] The in-machine measurement system for numerical control machining provided by this application adopts the following technical solutions: An in-machine measurement system for numerical control machining includes a grating scale body, a laser displacement sensor, and a circular grating encoder. The grating scale body and the laser displacement sensor collect axial profile data and transmit it to a data acquisition card. The laser displacement sensor and the circular grating encoder collect radial profile data and transmit it to the data acquisition card. The data acquisition card sends the collected data to a host computer.

[0008] By adopting the above technical solutions, the grating scale body set in the system can monitor the displacement change of the tool or the slide table in the axial direction in real time. Combining with the laser displacement sensor for non-contact measurement of the axial dimension, it improves the accuracy and stability of axial profile detection. At the same time, the combination of the laser displacement sensor and the circular grating encoder can synchronously collect the radial profile data of the workpiece in the rotating state, realize the dynamic detection of key parameters such as roundness and runout, and effectively improve the dimension control ability during the machining process. The data collected by various sensors are uniformly transmitted to the data acquisition card for summary processing and then transmitted to the host computer through industrial Ethernet, realizing high-speed and efficient data communication and visualization analysis, enhancing the intelligence and feedback response ability of the system. Through this system, key geometric parameters can be obtained in real time without affecting the machining process, improving the efficiency of product quality control, reducing rework and scrap rates caused by dimensional deviations, and being widely applicable to the quality control of the numerical control machining process in the field of high-precision manufacturing.

[0009] Optionally, the laser displacement sensor is fixedly installed on a vertical bracket. The vertical bracket is connected and fixed to the machine tool bed together with a horizontal fixture, which is used to clamp the laser displacement sensor fixture, the laser displacement sensor, and a servo motor. The laser displacement sensor is used to measure the size of the workpiece clamped on the machine tool spindle.

[0010] By adopting the above technical solutions, the stable fixation and precise positioning of the laser displacement sensor in the machine tool are realized, thus ensuring its high-precision measurement of the workpiece size during the machining process. The combined structure of the vertical bracket and the horizontal fixture improves the overall clamping firmness and anti-vibration performance, effectively avoiding the influence of machining vibration on the measurement accuracy of the sensor. At the same time, it enables the sensor to accurately align with the workpiece surface on the spindle, improving the reliability and repeatability of the measurement data, and providing a strong guarantee for the on-line dimension monitoring during the numerical control machining process.

[0011] Optionally, the in-machine measurement system controls the opening and closing of a protective cover. The protective cover is installed on the swing arm of the servo motor. The protective cover is controlled by the servo motor to flip to protect the laser displacement sensor and prevent the iron chips flying out during the cutting process from damaging the measurement accuracy of the laser displacement sensor.

[0012] By adopting the above technical solution, the protective cover is controlled by a servo motor to flip, can be automatically opened before machining and measurement, and automatically closed after measurement is completed. During the cutting process, it effectively blocks flying iron chips, dust and other sundries, avoiding damage or pollution to the laser displacement sensor, ensuring its measurement accuracy and service life. The servo drive structure ensures the accuracy and stability of the opening and closing actions of the protective cover, improving the automation level and reliability of the system.

[0013] Optionally, the scale body of the grating scale is fixed on the machine tool bed, and the reading head of the grating scale is fixed to the slide table through a reading head connecting piece to detect the axial movement dimension of the tool in real time.

[0014] By adopting the above technical solution, the scale body of the grating scale is fixed on the machine tool bed, and the reading head is installed on the slide table, which can collect displacement data synchronously with the movement of the tool, effectively reflecting the feed position and displacement change of the tool during the machining process, ensuring the precision control of the machining dimension. This structure has good stability and anti-interference ability, providing a high-reliability and high-resolution axial displacement detection means for the in-machine measurement system, and improving the overall machining quality and efficiency.

[0015] Optionally, the in-machine measurement system includes a circular grating encoder, and the circular grating encoder is fixed on the machine tool spindle through an encoder connecting piece to detect the rotation speed of the machine tool and the roundness of the workpiece to be measured in real time.

[0016] By adopting the above technical solution, the circular grating encoder is installed on the spindle, which can collect angle change data during the rotation of the spindle with high precision, and then calculate the rotation speed and analyze the roundness error of the workpiece. This structure improves the perception ability of the dynamic characteristics of the machining process, helps to detect machining abnormalities or deviations in time, optimize process parameters, improve machining quality and stability, and at the same time provides technical support for realizing intelligent and closed-loop controlled numerical control machining.

[0017] Optionally, data transmission between the data acquisition card and the upper computer is realized through an industrial Ethernet communication interface to improve the real-time performance and stability of data transmission.

[0018] By adopting the above technical solution, using the industrial Ethernet communication interface can effectively reduce the delay and interference in traditional serial communication, improve the real-time performance and stability of data transmission, ensure that the in-machine measurement data can be quickly and accurately transmitted to the upper computer for analysis and processing, not only improving the system response efficiency, but also laying a foundation for high-precision and continuous machining state monitoring and intelligent control.

[0019] Optionally, the fixture of the laser displacement sensor is made of anti-vibration and heat-insulating material to reduce the influence of heat sources and vibrations in the machining environment on the measurement accuracy of the sensor.

[0020] By adopting the above technical solutions, the fixture is made of vibration-resistant and heat-insulating materials, which can significantly reduce the interference of vibration and heat generated during machine tool processing on the sensor, ensure the stability of the measurement environment and the measurement accuracy of the sensor, extend the service life of the sensor, improve the overall reliability of the system, and provide a solid technical guarantee for high-precision on-line measurement.

[0021] Optionally, the servo motor is a multi-turn absolute value servo motor, which has the function of accurately controlling the opening and closing angle of the protective cover and feedbacking position information.

[0022] By adopting the above technical solutions, the multi-turn absolute value servo motor can accurately adjust the opening and closing angle of the protective cover, ensure its stable operation in the correct position, avoid misoperation or mechanical conflicts, and real-time feedback the position information of the protective cover, which helps system monitoring and fault diagnosis, improves the automation level and operation safety, and ensures the effective protection and measurement accuracy of the laser displacement sensor during the processing.

[0023] Optionally, the grating scale reading head has a temperature compensation function, which can maintain stable measurement accuracy under the change of processing temperature.

[0024] By adopting the above technical solutions, the temperature compensation function can effectively offset the measurement error caused by temperature fluctuations during the processing, ensure the accuracy and reliability of the axial displacement data, improve the environmental adaptability and accuracy stability of the measurement system, ensure the continuous provision of high-precision dimension detection data under complex processing conditions, and provide strong support for the precise control and quality assurance of the numerical control processing process.

[0025] Optionally, the resolution of the circular grating encoder is not less than 0.001°, so as to meet the requirements of high-precision workpiece roundness detection.

[0026] By adopting the above technical solutions, the resolution of the circular grating encoder reaches not less than 0.001°, which can carefully capture extremely small angular changes during the rotation of the main shaft, accurately reflect the roundness error of the workpiece, and the high resolution ensures the fineness and accuracy of the measurement data, meets the strict processing quality requirements, helps to detect and correct processing deviations in time, and improves the finished product rate and processing stability.

[0027] In summary, the present application includes at least one of the following beneficial technical effects: In the traditional processing process, manual measurement will have human errors or delays. The in-machine measurement system can automatically collect data and analyze it, reducing the need for manual intervention and improving the automation level. Through automated measurement, operators can focus on other tasks, further improving production efficiency.

[0028] 2. In - machine measurement enables operators to promptly detect any deviations or errors during the machining process, thus allowing for quick adjustments to ensure that the workpiece always meets the design requirements. This real - time feedback significantly improves machining accuracy and product quality. Moreover, continuous and real - time monitoring of each workpiece during the machining process ensures that every step of the machining process is within control. This automated precise control improves machining accuracy and avoids inconsistencies caused by human operation or equipment errors, making the dimensions of each produced workpiece more precise and consistent.

[0029] 3. The in - machine measurement system can continuously record the measurement data of each workpiece and archive it. This can provide detailed data support for later process traceability and also help analyze trends in the production process, detect potential quality problems or equipment failures, and perform maintenance in advance to avoid production interruptions.

[0030] 4. By installing a protective cover on the laser displacement sensor, the present invention can effectively prevent flying iron chips from hitting the surface of the laser displacement sensor during the cutting process, thereby preventing errors in the laser displacement sensor. This structural design ensures that the sensor can always maintain precise measurement accuracy during operation and avoids measurement errors caused by iron chips.

[0031] 5. The automatic flipping protective cover of the present invention has a simple structure and adopts an automated control design, avoiding complex manual operation processes. It is compact, reliable, and can seamlessly cooperate with existing numerical control machining systems, facilitating integration and installation. Operators only need to perform basic settings and adjustments, and there is no need for excessive intervention during use. The operation is simple, greatly improving the operation convenience of the production line. Brief Description of the Drawings

[0032] Figure 1 is the schematic diagram of the embodiment of the present application.

[0033] Figure 2 is the installation of the embodiment of the present application Figure 1 .

[0034] Figure 3 is the installation of the embodiment of the present application Figure 2 .

[0035] Figure 4 is the installation of the embodiment of the present application Figure 3 .

[0036] Figure 5 is the installation of the embodiment of the present application Figure 4 Explanation of the accompanying symbols: 1. Machine tool spindle; 2. Vertical bracket; 3. Horizontal fixture; 4. Protective cover; 5. Laser displacement sensor fixture; 6. Laser displacement sensor; 7. Servo swing arm; 8. Servo; 9. Grating scale body; 10. Grating scale reading head; 11. Reading head connector; 12. Circular grating encoder; 13. Encoder connector. DETAILED DESCRIPTION

[0037] The following is combined with Figures 1-5 This application is described in further detail.

[0038] The embodiment of the present application discloses a CNC machining on-machine measurement system. Figure 1 , including a grating scale body 9, a laser displacement sensor 6 and a circular grating encoder 12. The grating scale body 9 and the laser displacement sensor 6 collect axial profile data and transmit it to the data acquisition card. The laser displacement sensor 6 and the circular grating encoder 12 collect radial profile data and transmit it to the data acquisition card. The data acquisition card sends the collected data to the host computer and displays it. The data acquisition card and the host computer realize data transmission through the industrial Ethernet communication interface to improve the real-time and stability of data transmission. The grating scale body and the laser displacement sensor jointly collect axial profile data, and the laser displacement sensor and the circular grating encoder cooperate to collect radial profile data, so as to fully obtain the dimensional change information during the processing. Each sensor collects the data The data is transmitted to the data acquisition card in real time, and then the data acquisition card transmits the data quickly and stably to the host computer through the industrial Ethernet interface for analysis and display, which effectively improves the real-time performance of measurement data processing and the anti-interference ability of transmission. Without interfering with the normal processing flow, the system can dynamically monitor and timely feedback the processing accuracy status, which helps operators to make quick adjustments and improve processing quality and efficiency. At the same time, with the help of the data visualization function of the host computer, the measurement results can be intuitively presented and recorded and analyzed, providing reliable data support for product quality traceability and process optimization, effectively realizing real-time monitoring and feedback control of workpiece geometric parameters in the machine state, and enhancing the automation and intelligence level of CNC machining.

[0039] Reference Figure 2 、 Figure 3, the laser displacement sensor 6 is fixedly installed on the vertical bracket 2. The vertical bracket 2 is connected and fixed to the machine tool bed together with the horizontal fixture 3, which is used to clamp the laser displacement sensor fixture 5, the laser displacement sensor 6, and the servo motor 8. The laser displacement sensor fixture 5 is made of anti-vibration and heat-insulating material to reduce the influence of heat sources and vibrations in the processing environment on the measurement accuracy of the sensor. The laser displacement sensor 6 is used to measure the size of the workpiece clamped on the machine tool spindle 1. The servo motor 8 is a multi-turn absolute value servo motor, which has the function of accurately controlling the opening and closing angle of the protective cover and feedbacking position information. The laser displacement sensor 6 is installed on the vertical bracket 2 through the fixture 5 made of anti-vibration and heat-insulating material, and the whole is fixed to the machine tool bed by the horizontal fixture 3, effectively isolating the interference of mechanical vibrations and high-temperature heat sources generated during the processing on the performance of the sensor, thus significantly improving the stability and accuracy of the measurement data. The size information collected by the sensor can directly reflect the geometric characteristics of the workpiece on the machine tool spindle 1, ensuring real-time monitoring and feedback of size changes during the processing, and realizing on-line quality control of the workpiece. As a multi-turn absolute value servo motor, the servo motor 8 has the ability to accurately control the opening and closing angle of the protective cover and can feedback the current position in real time, effectively improving the automation and safety of the protection system. It automatically opens the protective cover for measurement before processing or during processing intervals, and closes the protective cover during processing to avoid chip splashing and damaging the laser sensor, thus ensuring the long-term stable operation of the equipment.

[0040] Refer to Figure 3 , the in-machine measurement system controls the opening and closing of the protective cover 4. The protective cover 4 is installed on the servo motor swing arm 7. The protective cover 4 is controlled by the servo motor 8 to flip to protect the laser displacement sensor 6, avoiding the measurement accuracy of the laser displacement sensor 6 being damaged by the iron chips flying out during the cutting process. The servo motor 8 controls the protective cover 4 to automatically open before measurement and automatically close after measurement, ensuring the cleanliness of the measurement environment and the service life of the sensor, improving the stability and reliability of the system, and providing a strong guarantee for high-precision and continuous measurement.

[0041] Refer to Figure 4 , the grating scale body 9 is fixed on the machine tool bed. The grating scale reading head 10 is fixed to the slide table through the reading head connecting piece 11 to detect the axial movement size of the tool in real time. The grating scale reading head 10 has a temperature compensation function and can maintain stable measurement accuracy under the change of processing temperature.

[0042] Refer to Figure 5 , the in-machine measurement system includes a circular grating encoder 12. The circular grating encoder 12 is fixed on the machine tool spindle through the encoder connecting piece 13 and can detect the rotation speed of the machine tool and the roundness of the measured workpiece in real time. The resolution of the circular grating encoder 12 is not less than 0.001°, meeting the requirements for high-precision workpiece roundness detection.

[0043] The implementation principle of the in-machine measurement system for numerical control machining in an embodiment of this application is as follows: The grating scale body 9 and the laser displacement sensor 6 are jointly used for the acquisition of axial profile data. The laser displacement sensor 6 and the circular grating encoder 12 cooperate to complete the acquisition of radial profile data. All the data collected by the sensors are uniformly transmitted to the data acquisition card, and the data acquisition card transmits the data to the upper computer for processing and visual display through the industrial Ethernet communication interface at high speed and stably. The grating scale body 9 is fixedly installed on the machine tool bed, and the reading head 10 is fixed to the slide table through the connecting piece 11, which is used to detect the axial movement dimension of the tool in real time. The reading head 10 has a temperature compensation function, which can maintain high measurement stability and accuracy in a high-temperature environment, effectively solving the problem of accuracy drift caused by temperature rise during the machining process. The laser displacement sensor 6 is fixedly installed on the vertical bracket 2 and is integrally fixed to the machine tool bed through the horizontal fixture 3. To ensure measurement stability, the laser displacement sensor fixture 5 is made of vibration-resistant and heat-insulating materials, effectively isolating the mechanical vibration and high-temperature heat source from the machining environment, thereby reducing the adverse impact on the measurement accuracy of the laser sensor. The laser displacement sensor 6 faces the workpiece to be machined on the machine tool spindle 1 and undertakes the task of real-time measurement of the workpiece size, capable of dynamically monitoring the size change during the machining process and feeding it back to the system control end. The servo motor 8 is a multi-turn absolute servo motor with a high-resolution position feedback function, which can accurately control the opening and closing angles of the protective cover 4. The protective cover 4 is installed on the servo motor swing arm 7 and is driven by the servo motor 8 to rotate and flip. In the non-machining state or measurement stage, the servo motor controls the protective cover to automatically open, enabling the laser displacement sensor to be in the working state. During the machining process, the protective cover automatically closes to prevent the iron chips flying out during the cutting process from hitting the sensor, thereby protecting the sensitive components and extending their service life, improving the automation level of the entire system, avoiding errors and risks caused by manual operation, and ensuring the long-term stable operation of the measurement system. The circular grating encoder 12 is installed on the machine tool spindle and is firmly connected to the spindle through the encoder connecting piece 13. The encoder is used to monitor the spindle speed and the roundness of the workpiece rotating with the spindle in real time. To meet the requirements of high-precision workpiece detection, the resolution of this circular grating encoder is designed to be not less than 0.001°, thereby achieving sub-angle-level rotation measurement accuracy and providing strong technical support for the precision manufacturing field. The industrial Ethernet communication interface adopted by the system can achieve high-speed and stable data transmission, greatly enhancing the anti-interference ability and real-time performance of the numerical control system in a complex machining environment. The data acquisition card efficiently collects various sensor signals and can also uniformly package and transmit the signals to the upper computer platform. The upper computer has powerful computing and display capabilities, capable of visualizing the analysis of the collected data, curve comparison, and historical data tracing, providing intuitive and accurate machining status information for the operator, assisting in judging the machining quality, and optimizing the process.

[0044] The application advantages of the in-machine measurement system for numerical control machining in the embodiments of this application are as follows: By integrating high-precision sensor technology, real-time data acquisition and processing, and closed-loop control with the numerical control system, the in-machine measurement system for numerical control machining ensures the precise monitoring and immediate adjustment of key parameters such as dimensions and shapes during the workpiece machining process. The system uses laser displacement sensors and grating scales to collect machining data in real time, analyzes the data through intelligent algorithms to detect machining deviations, and promptly feeds back to the computer to adjust machining parameters such as cutting speed, tool compensation, and feed rate, thereby ensuring machining accuracy and workpiece quality. In addition, the in-machine measurement system can not only monitor the quality of individual workpieces but also optimize the machining process through data analysis to improve the overall production efficiency. Its automation and intelligent control functions enable the entire production process to operate without manual intervention, thus reducing human measurement errors and enhancing production efficiency and stability. At the same time, the system can record the machining data of each workpiece, facilitating subsequent quality traceability and problem diagnosis, and ensuring the traceability and data support of the production process. Through the combination of these functions, the in-machine measurement system for numerical control machining achieves high-precision, high-efficiency, and low-cost machining control, becoming an important technical guarantee in modern manufacturing.

[0045] The above are all the preferred embodiments of this application. The protection scope of this application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of this application shall be covered within the protection scope of this application.

Claims

1. The on-machine measurement system for numerical control machining, characterized in that: It includes a linear scale body (9), a laser displacement sensor (6) and a circular grating encoder (12). The linear scale body (9) and the laser displacement sensor (6) collect axial profile data and transmit it to a data acquisition card. The laser displacement sensor (6) and the circular grating encoder (12) collect radial profile data and transmit it to the data acquisition card. The data acquisition card sends the collected data to a host computer.

2. The in-machine measurement system for numerical control machining according to claim 1, characterized in that: The laser displacement sensor (6) is fixedly installed on a vertical bracket (2). The vertical bracket (2) is connected to a horizontal fixture (3) and fixed on the machine tool bed, and is used to clamp a laser displacement sensor fixture (5), a laser displacement sensor (6) and a servo motor (8). The laser displacement sensor (6) is used to measure the size of a workpiece clamped on a machine tool spindle (1).

3. The in-machine measurement system for numerical control machining according to claim 1, wherein: The in-machine measurement system controls the opening and closing of a protective cover (4). The protective cover (4) is installed on a servo motor swing arm (7). The protective cover (4) is controlled by the servo motor (8) to flip to protect the laser displacement sensor (6) and prevent the cutting chips flying out during the cutting process from damaging the measurement accuracy of the laser displacement sensor (6).

4. The in-machine measurement system for numerical control machining according to claim 1, characterized in that: The linear scale body (9) is fixed on the machine tool bed. The linear scale reading head (10) is fixed to a slide table through a reading head connecting piece (11) to detect the axial movement size of the tool in real time.

5. The in-machine measurement system for numerical control machining according to claim 1, wherein: The in-machine measurement system includes a circular grating encoder (12). The circular grating encoder (12) is fixed on the machine tool spindle through an encoder connecting piece (13) and can detect the rotation speed of the machine tool and the roundness of the workpiece to be measured in real time.

6. The in-machine measurement system for numerical control machining according to claim 1, wherein: Data transmission between the data acquisition card and the host computer is realized through an industrial Ethernet communication interface to improve the real-time performance and stability of data transmission.

7. The in-machine measurement system for numerical control machining according to claim 2, wherein: The laser displacement sensor fixture (5) is made of an anti-vibration and heat-insulating material to reduce the influence of heat sources and vibrations in the processing environment on the measurement accuracy of the sensor.

8. The in-machine measurement system for numerical control machining according to claim 3, characterized in that: The servo motor (8) is a multi-turn absolute servo motor and has the function of accurately controlling the opening and closing angle of the protective cover and feedbacking position information.

9. The in-machine measurement system for numerical control machining according to claim 4, characterized in that: The linear scale reading head (10) has a temperature compensation function and can maintain a stable measurement accuracy under the change of processing temperature.

10. The in-machine measurement system for numerical control machining according to claim 5, characterized in that: The resolution of the circular grating encoder (12) is not less than 0.001° to meet the requirements of high-precision workpiece roundness detection.

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