A method for in-machine workpiece dimension detection and automatic machine adjustment in CNC machines

Abstract

This invention relates to a method for in-machine workpiece dimension detection and automatic machine adjustment in a CNC machine. The CNC machine is equipped with a probe and a contact-type tool setter. The method includes the following steps: Step 1: Machining the part with a tool, followed by blowing air onto the part to remove debris; Step 2: Controlling the probe to perform contact-type detection on the surface of the machined part according to NC code to collect the measured values ​​of the X-axis, Y-axis, and Z-axis positions of the measured positions, and recording them in a macro variable list; Step 3: Based on the CNC coordinate system, calculating the X-axis position error based on the theoretical and measured values ​​of the X-axis positions of the measured positions. This invention can improve the stability of key product dimensions, increase yield, reduce the workload of measurement and machine adjustment personnel, save labor costs, and reduce frequent machine adjustments caused by measurement errors.

Description

Technical Field

[0001] This invention relates to the field of CNC machining technology, and specifically to a method for in-machine workpiece dimension detection and automatic machine adjustment in CNC machining. Background Technology

[0002] CNC (Computer Numerical Control) refers to the technology of automatically controlling machine tools for high-precision machining through computer programs. It converts design drawings into digital instructions, driving lathes, milling machines, and other equipment to complete operations such as cutting, drilling, and engraving. CNC machine tools can achieve automated precision machining of materials such as metals by pre-programming parameters such as tool paths, spindle speeds, and feed rates. A typical application is machining centers, equipped with automatic tool changers, which can complete multiple processes such as drilling and milling in a single setup, significantly improving efficiency and accuracy. Modern CNC machine tools are developing towards higher speeds, higher precision, and greater intelligence, supporting the manufacturing of complex parts and widely used in machinery, mold making, aerospace, and other fields, forming one of the core foundations of advanced manufacturing technology.

[0003] In existing technology, after a CNC machine tool processes a part, the part is sent to the quality inspection department for inspection. If dimensional deviations are found, the quality inspection department then provides feedback to the CNC machine tool operator, who then adjusts the machining parameters of the CNC machine tool. Because the discovery and feedback of dimensional deviations are inevitably delayed, it is difficult to reduce the mass production of defective products. Summary of the Invention

[0004] The purpose of this invention is to provide a method for CNC machine workpiece dimension detection and automatic machine adjustment, which can improve the stability of key product dimensions, increase yield, reduce the workload of measurement and adjustment personnel, save labor costs, and reduce frequent machine adjustments caused by measurement errors.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for in-machine workpiece dimension detection and automatic machine adjustment in a CNC machine, wherein the CNC is equipped with a probe and a contact-type tool setter, includes the following steps: Step 1: Use a cutting tool to process the part, then blow air into the part and clean away any debris; Step 2: Control the probe to perform contact detection on the surface of the machined part according to the NC code to collect the measured values ​​of the X-axis position, Y-axis position and Z-axis position of the measured position, and record them in the macro variable list; Step 3: Based on the CNC coordinate system, calculate the X-axis position error according to the theoretical value and the measured value of the X-axis position of the position to be measured; calculate the Y-axis position error according to the theoretical value and the measured value of the Y-axis position of the position to be measured; calculate the Z-axis position error according to the theoretical value and the measured value of the Z-axis position of the position to be measured. Step 4: Place the current tool in contact with the contact tool setter and check the length compensation value and radius compensation value of the current tool; Step 5: Based on the length compensation value, the X-axis position error, the Y-axis position error, and the Z-axis position error, align the first origin of the CNC coordinate system. The position was adjusted, and the position of the second origin was calculated. ; Step 6: Perform error compensation on the tool radius of the tool according to the radius compensation value to obtain the compensated tool radius.

[0006] Specifically, in step two: the probe is controlled to perform contact-type detection on N test positions on the surface of the processed part; In step three: N sets of errors are measured. , , where i = 1, 2, 3, ..., N; In step four: Detect the current tool length compensation value. ; In step five: Calculate the average values ​​of the X, Y, and Z axis direction errors: ; Calculate the position of the second origin : .

[0007] Specifically, the N test locations are N points of the spatial curve toolpath, and the distribution and density of the N vertices are determined according to the workpiece structure and key dimensions.

[0008] Specifically, before step one: Use a standard calibration gauge to perform zero-point calibration on the contact tool setter to ensure that the measurement reference is consistent with the machine tool reference. Select the appropriate spring collet according to the tool type and install it on the tool holder. Pull down the spindle pull rod of the tool setter, install the tool holder, and then release the pull rod to ensure that the tool holder is fully tightened and tightly fitted with the tapered surface of the tool setter spindle.

[0009] Specifically, the reference plane of the tool holder is used as the starting point for length measurement.

[0010] Specifically, the measurement position is the location of the main cutting edge near the tip of the tool.

[0011] Specifically, the length reference measured by the tool setter is set to be consistent with the positioning reference of the inner tapered hole of the machine tool spindle.

[0012] Specifically, the ambient temperature of the tool setter should be similar to that of the machine tool processing environment, with a temperature difference of less than 5 degrees Celsius.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: After the CNC machine completes the machining of a single part, the control probe performs contact-type detection at N test positions on the part surface, and measures N sets of errors. , , Where i = 1, 2, 3, ..., N. The N positions to be measured are N points of the spatial curve toolpath, and the distribution and density of the N vertices are determined according to the workpiece structure and key dimensions.

[0014] Next, calculate the average error of N sets: ; Then, calculate the position of the second origin. : After a single part is machined by CNC, a probe is controlled to perform contact-type detection at N test positions on the part's surface. This immediately detects machining errors and corrects the origin position, ensuring that subsequent machining meets dimensional requirements without waiting for quality inspection feedback, thus preventing the production of batches of defective products. The in-machine inspection solution of this invention improves the stability of critical product dimensions, increases yield, reduces the workload of measurement and machine adjustment personnel, saves labor costs, and reduces frequent machine adjustments caused by measurement errors. Detailed Implementation

[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0016] A method for in-machine workpiece dimension detection and automatic machine adjustment in a CNC machine, wherein the CNC is equipped with a probe and a contact-type tool setter, includes the following steps: Step 1: Use a cutting tool to process the part, then blow air into the part and clean away any debris; Step 2: The control probe performs touch-type detection on the surface of the machined part to be tested according to the NC code. Specifically, the control probe performs touch-type detection on N positions to be tested on the surface of the machined part to collect the measured values ​​of the X-axis position, Y-axis position, and Z-axis position of the position to be tested, and records them in the macro variable list.

[0017] Step 3: Based on the CNC coordinate system, calculate the X-axis position error using the theoretical and measured values ​​of the X-axis position of the position to be measured. Calculate the Y-axis position error using the theoretical and measured values ​​of the Y-axis position of the position to be measured. Calculate the Z-axis position error using the theoretical and measured values ​​of the Z-axis position of the position to be measured. N sets of errors are obtained for the above N positions to be measured. , , where i = 1, 2, 3, ..., N; Step 4: Place the current tool in contact with the contact tool setter and detect the length compensation value of the current tool. With radius compensation value; Step 5: Based on the length compensation value, the X-axis position error, the Y-axis position error, and the Z-axis position error, align the first origin of the CNC coordinate system. The position was adjusted, and the position of the second origin was calculated. Specifically: First, calculate the average error in the X, Y, and Z axes: ; Then, calculate the position of the second origin. : .

[0018] Step 6: Perform error compensation on the tool radius of the tool according to the radius compensation value to obtain the compensated tool radius.

[0019] Specifically, the N test locations are N points of the spatial curve toolpath, and the distribution and density of the N vertices are determined according to the workpiece structure and key dimensions.

[0020] Specifically, before step one: use a standard calibration gauge to perform zero-point calibration on the contact tool setter to ensure that the measurement reference is consistent with the machine tool reference; Select the appropriate spring collet according to the tool type and install it on the tool holder. Pull down the spindle pull rod of the tool setter, install the tool holder, and then release the pull rod to ensure that the tool holder is fully tightened and tightly fitted with the tapered surface of the tool setter spindle.

[0021] Specifically, the reference plane of the tool holder is used as the starting point for length measurement.

[0022] Specifically, the measurement position is the location of the main cutting edge near the tip of the tool.

[0023] Specifically, the length reference measured by the tool setter is set to be consistent with the positioning reference of the inner tapered hole of the machine tool spindle.

[0024] Specifically, the ambient temperature of the tool setter should be similar to that of the machine tool processing environment, with a temperature difference of less than 5 degrees Celsius.

[0025] The working principle of this invention is as follows: After the CNC machine completes the machining of a single part, the control probe performs contact-type detection at N test positions on the part surface, and measures N sets of errors. , , Where i = 1, 2, 3, ..., N. The N positions to be measured are N points of the spatial curve toolpath, and the distribution and density of the N vertices are determined according to the workpiece structure and key dimensions.

[0026] Next, calculate the average error of N sets: ; Then, calculate the position of the second origin. : After a single part is machined by CNC, a probe is controlled to perform contact-type detection at N test positions on the part's surface. This immediately detects machining errors and corrects the origin position, ensuring that subsequent machining meets dimensional requirements without waiting for quality inspection feedback, thus preventing the production of batches of defective products. The in-machine inspection solution of this invention improves the stability of critical product dimensions, increases yield, reduces the workload of measurement and machine adjustment personnel, saves labor costs, and reduces frequent machine adjustments caused by measurement errors.

[0027] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for in-machine workpiece dimension detection and automatic machine adjustment in a CNC machine, wherein the CNC is equipped with a probe and a contact-type tool setter, characterized in that, Includes the following steps: Step 1: Use a cutting tool to process the part, then blow air into the part and clean away any debris; Step 2: Control the probe to perform contact detection on the surface of the machined part according to the NC code to collect the measured values ​​of the X-axis position, Y-axis position and Z-axis position of the measured position, and record them in the macro variable list; Step 3: Based on the CNC coordinate system, calculate the X-axis position error according to the theoretical value and the measured value of the X-axis position of the position to be measured; calculate the Y-axis position error according to the theoretical value and the measured value of the Y-axis position of the position to be measured; calculate the Z-axis position error according to the theoretical value and the measured value of the Z-axis position of the position to be measured. Step 4: Place the current tool in contact with the contact tool setter and check the length compensation value and radius compensation value of the current tool; Step 5: Based on the length compensation value, the X-axis position error, the Y-axis position error, and the Z-axis position error, align the first origin of the CNC coordinate system. The position was adjusted, and the position of the second origin was calculated. ; Step 6: Perform error compensation on the tool radius of the tool according to the radius compensation value to obtain the compensated tool radius.

2. The method for CNC machine workpiece dimension detection and automatic machine adjustment according to claim 1, characterized in that: In step two: the probe is controlled to perform contact-type detection on N test positions on the surface of the machined part; In step three: N sets of errors are measured. , , where i = 1, 2, 3, ..., N; In step four: Detect the current tool length compensation value. ; In step five: Calculate the average values ​​of the X, Y, and Z axis direction errors: ； Calculate the position of the second origin : 。 3. The method for CNC machine workpiece dimension detection and automatic machine adjustment according to claim 2, characterized in that, The N test locations are N points of the spatial curve toolpath, and the distribution and density of the N vertices are determined according to the workpiece structure and key dimensions.

4. The method for CNC machine workpiece dimension detection and automatic machine adjustment according to claim 1, characterized in that, Before step one: Use a standard calibration gauge to perform zero-point calibration on the contact tool setter to ensure that the measurement reference is consistent with the machine tool reference. Select the appropriate spring collet according to the tool type and install it on the tool holder. Pull down the spindle pull rod of the tool setter, install the tool holder, and then release the pull rod to ensure that the tool holder is fully tightened and tightly fitted with the tapered surface of the tool setter spindle.

5. The method for CNC machine workpiece dimension detection and automatic machine adjustment according to claim 1, characterized in that, The reference plane of the tool holder is used as the starting point for length measurement.

6. The method for CNC machine workpiece dimension detection and automatic machine adjustment according to claim 1, characterized in that, The measurement position is taken as the position of the main cutting edge near the tip of the tool.

7. The method for CNC machine workpiece dimension detection and automatic machine adjustment according to claim 1, characterized in that, The length reference measured by the tool setter is set to be consistent with the positioning reference of the inner tapered hole of the machine tool spindle.

8. The method for CNC machine workpiece dimension detection and automatic machine adjustment according to claim 1, characterized in that, The ambient temperature of the tool setter should be similar to that of the machine tool processing environment, with a temperature difference of less than 5 degrees Celsius.

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