A five-axis machine tool A-axis thermal deformation detection method based on a trigger probe

Abstract

The present application relates to five-axis machine tool thermal deformation detection technical field, disclose a kind of five-axis machine tool A-axis thermal deformation detection method based on trigger probe, comprising: when machine tool is powered on, the coordinates of each measurement reference point at each measurement position are measured, the initial ball center coordinates of standard ball at each measurement position when powered on are calculated;Enter rotating shaft cycle phase, the coordinates of each measurement reference point at each measurement position are measured, the ball center coordinates of standard ball at each measurement position in cycle phase are calculated, and the thermal deformation value of A-axis is calculated, whether it is judged to reach cooling condition, if yes, enter cooling stage, otherwise, rotating shaft cycle phase is executed;Enter cooling stage, the coordinates of each measurement reference point at each measurement position are measured, the ball center coordinates of standard ball at each measurement position are calculated, and the thermal deformation value of A-axis is calculated, whether it is judged to reach interrupt measurement condition, if yes, the thermal deformation value detection result of A-axis is obtained;The method improves detection precision and realizes the comprehensive detection of five-axis machine tool A-axis thermal deformation.

Description

Technical Field

[0001] This invention relates to the field of thermal deformation detection technology for five-axis machine tools, and specifically to a method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe. Background Technology

[0002] In the equipment manufacturing industry, CNC machine tools are hailed as the "mother machines of industry," and their development quality is a crucial indicator of a country's equipment manufacturing level. During machine tool processing, thermal deformation accounts for 40% to 70% of the total error. Therefore, thermal deformation measurement technology is vital in machine tool research. Currently, the international standard "General Rules for Machine Tool Inspection - Part 3: Determination of Thermal Effects" (ISO 230-3:2020) is widely used for thermal deformation measurement of five-axis machine tools. According to this standard, the method for detecting thermal deformation of the A-axis of a machine tool is as follows: A thermal deformation probe device with three displacement sensors is installed on the machine tool spindle to measure the displacement in the X, Y, and Z directions. A standard ball is installed on the worktable. By rotating the worktable and linearly moving the spindle, the offset of the standard ball at the three measurement positions is measured, and the amount of thermal deformation caused by the rotation of the A-axis is calculated. Although this method can detect the thermal deformation of the A-axis by calculating the amount of thermal deformation caused by the rotation of the A-axis, the matrix arrangement of the thermal deformation probe device results in a large spatial interference range, making it difficult to implement for certain types of machine tools. Summary of the Invention

[0003] To address the aforementioned shortcomings in the prior art, this invention provides a method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe, which solves the problem of large spatial interference of the probe in the prior art, thereby improving the accuracy of thermal deformation detection of the five-axis machine tool.

[0004] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: A method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe includes the following steps: S1. Preset several measurement reference points on the standard ball and preset the position of the standard ball on the five-axis machine tool table plane. At the same time, according to the travel of the A-axis of the five-axis machine tool, preset several measurement positions and install the trigger probe on the spindle above the five-axis machine tool table. Use the spindle to drive the trigger probe to perform linear motion. S2. When the five-axis machine tool is turned on, move the spindle and the five-axis machine tool worktable, and use the trigger probe to measure the coordinates of each measurement reference point at each measurement position in sequence, and calculate the initial sphere center coordinates of the standard sphere at each measurement position when the machine is turned on. S3. Enter the rotation cycle stage, rotate axis A and stop rotating axis A when the rotation time of axis A reaches the first set threshold. Use the trigger probe to measure the coordinates of each measurement reference point at each measurement position in sequence, and calculate the center coordinates of the standard ball at each measurement position in the cycle stage. The axis rotation cycle phase refers to the state when axis A is running normally. S4. Calculate the thermal deformation value of the A-axis during the rotation phase based on the initial center coordinates of the standard spheres at each measurement position when the machine is turned on and the center coordinates of the standard spheres at each measurement position during the circulation phase. S5. Determine whether the thermal deformation value of the A-axis during the shaft circulation stage has reached the cooling stage condition. If yes, proceed to step S6; otherwise, proceed to step S3. S6. When entering the cooling stage, stop rotating the A-axis. When the time elapsed since entering the cooling stage reaches the second set threshold, use the trigger probe to measure the coordinates of each measurement reference point at each measurement position in sequence, and calculate the center coordinates of the standard sphere at each measurement position during the cooling stage. The cooling phase refers to the state when the A-axis is not running. S7. Calculate the thermal deformation value of the A-axis during the cooling stage based on the initial center coordinates of the standard spheres at each measurement position when the machine is turned on and the center coordinates of the standard spheres at each measurement position during the cooling stage. S8. Determine whether the thermal deformation value of the A-axis during the cooling stage meets the interruption measurement condition. If yes, proceed to the interruption measurement stage and obtain the thermal deformation value detection result of the A-axis. Otherwise, execute step S6.

[0005] Furthermore, step S1 specifically includes: S11. Preset four measurement reference points on the standard ball and install the standard ball on the plane of the five-axis machine tool table, keeping the installation position of the standard ball away from the center of the five-axis machine tool table and the line connecting the standard ball and the center of the five-axis machine tool table parallel to the X-axis direction. The four measurement reference points are the first measurement reference point, the second measurement reference point, the third measurement reference point, and the fourth measurement reference point. S12. Based on the travel of the A-axis of the five-axis machine tool, preset three measurement positions; The three measurement positions are the first measurement position, the second measurement position, and the third measurement position. If the travel of the A-axis of the five-axis machine tool is less than -60° or 60°, then three measurement positions are selected at equal intervals according to the actual travel of the A-axis of the five-axis machine tool, and the first measurement position and the third measurement position are symmetrically distributed. If the travel of the A-axis of the five-axis machine tool is greater than -60° or 60°, then the A-axis of the five-axis machine tool is set at the positions of -60°, 0°, and 60° as the first measurement position, the second measurement position, and the third measurement position, respectively. S13. Install the trigger probe onto the spindle above the five-axis machine tool table, and use the spindle to drive the trigger probe to perform linear motion.

[0006] Furthermore, step S2 specifically includes: When the five-axis machine tool is turned on, the machine tool table rotates along the A-axis. At the same time, the spindle of the five-axis machine tool drives the trigger probe to make linear motion along the X-axis, Y-axis or Z-axis. By contacting the measurement reference points of the standard ball at each measurement position in sequence, the coordinates of each measurement reference point are obtained, and the initial center coordinates of the standard ball at each measurement position are calculated when the machine is turned on.

[0007] Furthermore, the condition for entering the cooling stage in step S6 is that the maximum difference in thermal deformation in the five directions of X-axis, Y-axis, Z-axis, A-axis, B-axis or X-axis, Y-axis, Z-axis, A-axis, C-axis in the last hour of the shaft circulation stage is less than 15% of that in the first hour of the shaft circulation stage.

[0008] Furthermore, the condition for entering the interrupted measurement stage in step S8 is that the maximum difference in thermal deformation in the five directions of X-axis, Y-axis, Z-axis, A-axis, B-axis or X-axis, Y-axis, Z-axis, A-axis, C-axis in the last hour of the cooling stage is less than 15% of that in the first hour of the cooling stage.

[0009] Furthermore, the calculation formulas for the initial center coordinates of the standard spheres at each measurement position during power-on in step S2, the center coordinates of the standard spheres at each measurement position during the looping phase in step S3, and the center coordinates of the standard spheres at each measurement position during the cooling phase in step S6 are the same and are as follows:

[0010] in, Indicates the first At each measurement time, , They represent the first Measurement position at each measurement time Different intermediate matrices at different locations, , , , They represent the first Measurement position at each measurement time The coordinates of the first, second, third, and fourth measurement reference points in the X-axis direction. , , , They represent the first Measurement position at each measurement time The coordinates of the first, second, third, and fourth measurement reference points in the Y-axis direction. , , , They represent the first Measurement position at each measurement time The coordinate values ​​of the first, second, third, and fourth measurement reference points in the Z-axis direction. , , , They represent the first The coordinates of the first measurement reference point at the first measurement position, the second measurement reference point at the second measurement position, the third measurement reference point at the third measurement position, and the fourth measurement reference point at the fourth measurement position in the X-axis direction at each measurement time. , , , They represent the first The coordinates of the first measurement reference point at the first measurement position, the second measurement reference point at the second measurement position, the third measurement reference point at the third measurement position, and the fourth measurement reference point at the fourth measurement position in the Y-axis direction at each measurement time. , , , They represent the first The coordinate values ​​of the first measurement reference point at the first measurement position, the second measurement reference point at the second measurement position, the third measurement reference point at the third measurement position, and the fourth measurement reference point at the fourth measurement position in the Z-axis direction at each measurement time. , , They represent the first Measurement position at each measurement time The coordinates of the center of the standard sphere at that location in the X, Y, and Z axes.

[0011] Furthermore, the thermal deformation value of the A-axis in the rotation cycle stage in step S4 and the thermal deformation value of the A-axis in the cooling stage in step S7 both include linear displacement thermal deformation in the X-axis, Y-axis, and Z-axis directions, angular displacement thermal deformation in the A-axis direction, angular displacement thermal deformation in the B-axis direction, or angular displacement thermal deformation in the C-axis direction.

[0012] Furthermore, the formulas for calculating linear displacement thermal deformation in the X, Y, and Z axis directions are as follows:

[0013] in, Indicates the initial time. , , They represent the first The linear displacement thermal deformation values ​​of axis A in the X, Y, and Z axes at each measurement time. , , They represent the first The coordinates of the center of the standard sphere at the first measurement position at each measurement moment in the X, Y, and Z axes. , , They represent the first The coordinates of the center of the standard sphere at the third measurement position at each measurement moment in the X, Y, and Z axes. , , These represent the coordinates of the initial center of the standard sphere at the first measurement position along the X, Y, and Z axes, respectively. , , These represent the coordinates of the initial center of the standard sphere at the third measurement position in the X, Y, and Z axes, respectively.

[0014] Furthermore, the formula for calculating the angular displacement thermal deformation in the A-axis direction is:

[0015] in, Indicates the first The angular displacement thermal deformation value of axis A in the direction of axis A at each measurement time. This represents the Y-axis distance between the centers of the standard spheres at the first and third measurement positions.

[0016] Furthermore, the calculation formulas for angular displacement thermal deformation in the B-axis direction or the C-axis direction are as follows:

[0017] in, Indicates the first The angular displacement thermal deformation value of axis A in the direction of axis B at each measurement time. Indicates the first The angular displacement thermal deformation value of axis A in the direction of axis C at each measurement time. This represents the coordinates of the initial center of the standard sphere at the second measurement position along the X-axis. This represents the coordinates of the initial center of the standard sphere at the third measurement position along the Y-axis.

[0018] The present invention has the following beneficial effects: This invention proposes a method for detecting the thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe. By selecting multiple measurement positions and combining them with coordinate measurements using a trigger-type probe, it can accurately record and evaluate the thermal deformation of the A-axis. It can measure not only the linear displacement thermal deformation of the A-axis in the X, Y, and Z axes, but also the angular displacement thermal deformation in the A-axis, B-axis, and C-axis directions. This improves machining accuracy and production efficiency, enabling comprehensive detection of the thermal deformation of the A-axis of complex five-axis machine tools. It solves the technical problem of large spatial interference range that may occur with existing probe devices. Furthermore, while improving measurement accuracy, it expands the application scope, comprehensively reflecting the thermal deformation of the A-axis of a five-axis machine tool, and has broad application prospects. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating a five-axis machine tool A-axis thermal deformation detection method based on a trigger-type probe proposed in this invention. Figure 2 This is a schematic diagram of the structure of the five-axis machine tool with the trigger probe in the embodiment; Figure 3 This is a schematic diagram showing the positional relationship of each measurement location in the embodiment; Figure 4 This is a schematic diagram showing the positional relationship of the various measurement reference points of the standard sphere in the embodiment. Detailed Implementation

[0020] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0021] like Figure 1 As shown, a method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe includes the following steps S1-S8: S1. Preset several measurement reference points on the standard ball and preset the position of the standard ball on the five-axis machine tool table plane. At the same time, according to the travel of the A-axis of the five-axis machine tool, preset several measurement positions and install the trigger probe on the spindle above the five-axis machine tool table. Use the spindle to drive the trigger probe to perform linear motion.

[0022] In this embodiment, the structure of the five-axis machine tool with the trigger probe is as follows: Figure 2As shown, it includes a spindle 1, an online probe 2, a cradle 3, a standard ball 4, a clamp 5, and a worktable 6, wherein the online probe is the trigger-type probe described in this invention; furthermore, the measurement position of the standard ball is as follows... Figure 3 As shown, with the center of the worktable at 0° for both A-axis and C-axis as the reference origin, a Cartesian coordinate system of X, Y, and Z axes is established according to the national machine tool coordinate system standard. When the A-axis is at -60°, 0°, and 60° respectively (this can be adjusted according to the actual A-axis travel of the machine tool), the position of the standard ball is the measurement position; simultaneously, the positional relationship of each measurement reference point on the standard ball is as follows. Figure 4 As shown, Figure 4 The system includes a first measurement reference point, a second measurement reference point, a third measurement reference point, and a fourth measurement reference point. The principle is as follows: based on four non-coplanar points in space, the center and radius of the space sphere can be calculated. The positions of the measurement reference points are arranged such that the first measurement reference point is located at the highest point of the standard sphere, and the second, third, and fourth measurement reference points are evenly distributed on the equator of the standard sphere. This not only facilitates measurement but also minimizes measurement errors.

[0023] Specifically, step S1 includes S11-S13: S11. Preset four measurement reference points on the standard ball and install the standard ball on the plane of the five-axis machine tool table, keeping the installation position of the standard ball away from the center of the five-axis machine tool table and the line connecting the standard ball and the center of the five-axis machine tool table parallel to the X-axis direction; wherein, the four measurement reference points are the first measurement reference point, the second measurement reference point, the third measurement reference point, and the fourth measurement reference point.

[0024] S12. Based on the travel of the A-axis of the five-axis machine tool, preset three measurement positions.

[0025] The three measurement positions are the first measurement position, the second measurement position, and the third measurement position.

[0026] If the A-axis travel of the five-axis machine tool is less than -60° or 60°, then three measurement positions are selected at equal intervals according to the actual travel of the A-axis of the five-axis machine tool, and the first measurement position and the third measurement position are symmetrically distributed.

[0027] If the A-axis travel of the five-axis machine tool is greater than -60° or 60°, then the A-axis of the five-axis machine tool is set at the positions of -60°, 0°, and 60° as the first measurement position, the second measurement position, and the third measurement position, respectively.

[0028] S13. Install the trigger probe onto the spindle above the five-axis machine tool table, and use the spindle to drive the trigger probe to perform linear motion.

[0029] S2. When the five-axis machine tool is turned on, move the spindle and the five-axis machine tool worktable, and use the trigger probe to measure the coordinates of each measurement reference point at each measurement position in sequence, and calculate the initial sphere center coordinates of the standard sphere at each measurement position when the machine is turned on.

[0030] Specifically, step S2 includes: When the five-axis machine tool is turned on, the machine tool table rotates along the A-axis. At the same time, the spindle of the five-axis machine tool drives the trigger probe to make linear motion along the X-axis, Y-axis or Z-axis. By contacting the measurement reference points of the standard ball at each measurement position in sequence, the coordinates of each measurement reference point are obtained, and the initial center coordinates of the standard ball at each measurement position are calculated when the machine is turned on.

[0031] Specifically, the formula for calculating the initial center coordinates of the standard sphere at each measurement position during power-on in step S2 is as follows:

[0032] in, Indicates the first At each measurement time, , They represent the first Measurement position at each measurement time Different intermediate matrices at different locations, , , , They represent the first Measurement position at each measurement time The coordinates of the first, second, third, and fourth measurement reference points in the X-axis direction. , , , They represent the first Measurement position at each measurement time The coordinates of the first, second, third, and fourth measurement reference points in the Y-axis direction. , , , They represent the first Measurement position at each measurement time The coordinate values ​​of the first, second, third, and fourth measurement reference points in the Z-axis direction. , , , They represent the first The coordinates of the first measurement reference point at the first measurement position, the second measurement reference point at the second measurement position, the third measurement reference point at the third measurement position, and the fourth measurement reference point at the fourth measurement position in the X-axis direction at each measurement time. , , , They represent the first The coordinates of the first measurement reference point at the first measurement position, the second measurement reference point at the second measurement position, the third measurement reference point at the third measurement position, and the fourth measurement reference point at the fourth measurement position in the Y-axis direction at each measurement time. , , , They represent the first The coordinate values ​​of the first measurement reference point at the first measurement position, the second measurement reference point at the second measurement position, the third measurement reference point at the third measurement position, and the fourth measurement reference point at the fourth measurement position in the Z-axis direction at each measurement time. , , They represent the first Measurement position at each measurement time The coordinates of the center of the standard sphere at that location in the X, Y, and Z axes.

[0033] S3. Enter the axis rotation cycle stage, rotate axis A and stop rotating axis A when the rotation time of axis A reaches the first set threshold. Use the trigger probe to measure the coordinates of each measurement reference point at each measurement position in sequence, and calculate the center coordinates of the standard ball at each measurement position in the cycle stage. The axis rotation cycle stage is the state when axis A is running normally.

[0034] In this embodiment, the relationship between the spindle circulation stage and the cooling stage is as follows: when the measurement begins, the five-axis machine tool enters the spindle circulation stage; when the thermal deformation of the five-axis machine tool meets the conditions for entering the cooling stage, the measurement experiment enters the cooling stage; and during the measurement in the cooling stage, if the thermal deformation of the five-axis machine tool meets the conditions for interrupting the measurement, the experiment terminates. Furthermore, both the spindle circulation stage and the cooling stage consist of multiple measurement time intervals, and each interval... Each measurement time utilizes a trigger-type probe to sequentially measure the coordinates of each measurement reference point at each measurement location, thereby calculating the center coordinates of the standard sphere at each measurement location. Furthermore, a first set threshold is... ,in, are natural numbers and That is, every At each measurement moment, the coordinates of each measurement reference point at each measurement position are measured sequentially using a trigger probe. At the same time, the calculation formula for the center coordinates of the standard sphere at each measurement position during the cycle is the same as the calculation formula for the initial center coordinates of the standard sphere at each measurement position when the machine is turned on. By substituting the data measured in this stage into the formula, the center coordinates of the sphere at each measurement moment in this stage can be calculated.

[0035] S4. Based on the initial center coordinates of the standard spheres at each measurement position when the machine is turned on and the center coordinates of the standard spheres at each measurement position during the cycle phase, calculate the thermal deformation value of the A-axis during the cycle phase of the rotating shaft.

[0036] In this embodiment, the five axes of the five-axis machine tool are three linear motion axes (X, Y, and Z) and two rotary axes (A, B, or C). This embodiment focuses on thermal deformation detection of the A-axis of the five-axis machine tool, i.e., the A-axis is fixed, and the remaining rotary axes are either the B-axis or the C-axis. Therefore, when the remaining rotary axis is the B-axis, the detection of the corresponding direction of the A-axis includes linear displacement thermal deformation in the X, Y, and Z-axis directions, angular displacement thermal deformation in the A-axis direction, and angular displacement thermal deformation in the B-axis direction. When the remaining rotary axis is the C-axis, the detection of the corresponding direction of the A-axis includes linear displacement thermal deformation in the X, Y, and Z-axis directions, angular displacement thermal deformation in the A-axis direction, and angular displacement thermal deformation in the C-axis direction. The calculation formulas are as follows: Specifically, the formulas for calculating linear displacement thermal deformation in the X, Y, and Z axis directions are as follows:

[0037] in, Indicates the initial time. , , They represent the first The linear displacement thermal deformation values ​​of axis A in the X, Y, and Z axes at each measurement time. , , They represent the first The coordinates of the center of the standard sphere at the first measurement position at each measurement moment in the X, Y, and Z axes. , , They represent the first The coordinates of the center of the standard sphere at the third measurement position at each measurement moment in the X, Y, and Z axes. , , These represent the coordinates of the initial center of the standard sphere at the first measurement position along the X, Y, and Z axes, respectively. , , These represent the coordinates of the initial center of the standard sphere at the third measurement position in the X, Y, and Z axes, respectively.

[0038] Specifically, the formula for calculating the angular displacement thermal deformation in the A-axis direction is:

[0039] in, Indicates the first The angular displacement thermal deformation value of axis A in the direction of axis A at each measurement time. This represents the Y-axis distance between the centers of the standard spheres at the first and third measurement positions.

[0040] Specifically, the calculation formulas for angular displacement thermal deformation in the B-axis direction or angular displacement thermal deformation in the C-axis direction are as follows:

[0041] in, Indicates the first The angular displacement thermal deformation value of axis A in the direction of axis B at each measurement time. Indicates the first The angular displacement thermal deformation value of axis A in the direction of axis C at each measurement time. This represents the coordinates of the initial center of the standard sphere at the second measurement position along the X-axis. This represents the coordinates of the initial center of the standard sphere at the third measurement position along the Y-axis.

[0042] S5. Determine whether the thermal deformation value of axis A during the shaft circulation stage has reached the cooling stage condition. If yes, proceed to step S6; otherwise, proceed to step S3.

[0043] S6. Enter the cooling stage, stop rotating the A-axis, and when the time elapsed since entering the cooling stage reaches the second set threshold, use the trigger probe to sequentially measure the coordinates of each measurement reference point at each measurement position, and calculate the center coordinates of the standard sphere at each measurement position during the cooling stage; wherein, the cooling stage is the state in which the A-axis stops running.

[0044] In this embodiment, the second set threshold is ,in, are natural numbers and That is, every At each measurement moment, the coordinates of each measurement reference point at each measurement position are measured sequentially using a trigger probe, thereby calculating the center coordinates of the standard sphere at each measurement position during the cooling stage.

[0045] Specifically, the condition for entering the cooling stage in step S6 is that the maximum difference in thermal deformation in the five directions of X-axis, Y-axis, Z-axis, A-axis, B-axis or X-axis, Y-axis, Z-axis, A-axis, C-axis in the last hour of the rotation cycle stage is less than 15% of that in the first hour of the rotation cycle stage.

[0046] In this embodiment, the X-axis is used as an example to clearly illustrate the conditions for entering the cooling stage, specifically: The preset measurement time interval is ,in, This represents the maximum (minimum) thermal deformation of axis A in the X-axis direction within the current hour; This represents the maximum (minimum) thermal deformation of axis A in the X-axis direction during the first hour of the shaft rotation cycle. During the shaft rotation cycle, the difference between the current hour and the maximum thermal deformation of axis A in the X-axis direction during the first hour of the rotation cycle is compared to determine the result. Is it less than 15%?

[0047] At the same time, the same operation is performed on the remaining Y-axis, Z-axis, A-axis, B-axis or Y-axis, Z-axis, A-axis, C-axis directions. When the maximum thermal deformation difference at all measurement times in all directions is less than 15%, the cooling stage is entered; otherwise, the axis rotation cycle stage continues.

[0048] S7. Calculate the thermal deformation value of the A-axis during the cooling stage based on the initial center coordinates of the standard spheres at each measurement position when the machine is turned on and the center coordinates of the standard spheres at each measurement position during the cooling stage.

[0049] In this embodiment, the thermal deformation value of the A-axis in the cooling stage also includes linear displacement thermal deformation in the X-axis, Y-axis, and Z-axis directions, angular displacement thermal deformation in the A-axis direction, angular displacement thermal deformation in the B-axis direction, and angular displacement thermal deformation in the C-axis direction. Furthermore, the calculation formula for the thermal deformation value of the A-axis in the cooling stage is the same as the calculation formula for the thermal deformation value of the A-axis in the shaft circulation stage. That is, by substituting the data in this stage into the above formula, the thermal deformation value of the A-axis in the cooling stage can be calculated.

[0050] S8. Determine whether the thermal deformation value of the A-axis during the cooling stage meets the interruption measurement condition. If yes, proceed to the interruption measurement stage and obtain the thermal deformation value detection result of the A-axis. Otherwise, execute step S6.

[0051] Specifically, the condition for entering the interruption measurement stage in step S8 is that the maximum difference in thermal deformation in the five directions of X-axis, Y-axis, Z-axis, A-axis, B-axis or X-axis, Y-axis, Z-axis, A-axis, C-axis in the last hour of the cooling stage is less than 15% of that in the first hour of the cooling stage.

[0052] In this embodiment, taking the X-axis as an example, the conditions for entering the interrupted measurement stage are clearly explained as follows: The preset measurement time interval is , This represents the maximum (minimum) thermal deformation of axis A in the X-axis direction within the current hour; This represents the maximum (minimum) thermal deformation of the A-axis in the X-axis direction during the first hour of the cooling phase. During the cooling phase, the difference between the current hour and the maximum thermal deformation of the A-axis in the X-axis direction during the first hour of the cooling phase is compared to determine... Is it less than 15%?

[0053] Simultaneously, the same operation is performed on the remaining Y-axis, Z-axis, A-axis, B-axis or Y-axis, Z-axis, A-axis, C-axis. When the maximum thermal deformation difference in all directions at all measurement times is less than 15%, the measurement is interrupted to determine the deformation status of the A-axis based on the thermal deformation value of the A-axis during the cooling phase. Otherwise, the cooling phase continues.

[0054] In summary, the five-axis machine tool A-axis thermal deformation detection method proposed in this invention, based on a trigger-type probe, accurately records and evaluates the thermal deformation of the A-axis by selecting multiple measurement positions and combining coordinate measurements with a trigger-type probe. Specifically, it calculates the displacement thermal deformation of the A-axis along the X, Y, and Z axes, as well as the angular thermal deformation along the A, B, or C axes, using the coordinate changes of the center of a standard sphere at each measurement position after thermal deformation. This allows for accurate measurement and evaluation of the thermal deformation of the five-axis machine tool A-axis, improving machining accuracy and production efficiency. It also enables comprehensive detection of thermal deformation of the A-axis in complex five-axis machine tools, thus solving the technical problem of potentially large spatial interference ranges caused by probe devices used in existing technologies. This method can serve as an important supplement to international measurement methods. Furthermore, while improving measurement accuracy, this method expands its application scope, comprehensively reflecting the thermal deformation of the five-axis machine tool A-axis, and has broad application prospects.

[0055] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

[0056] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe, characterized in that, Includes the following steps: S1. Preset several measurement reference points on the standard ball and preset the position of the standard ball on the five-axis machine tool table plane. At the same time, according to the travel of the A-axis of the five-axis machine tool, preset several measurement positions and install the trigger probe on the spindle above the five-axis machine tool table. Use the spindle to drive the trigger probe to perform linear motion. S2. When the five-axis machine tool is turned on, move the spindle and the five-axis machine tool worktable, and use the trigger probe to measure the coordinates of each measurement reference point at each measurement position in sequence, and calculate the initial sphere center coordinates of the standard sphere at each measurement position when the machine is turned on. S3. Enter the rotation cycle stage, rotate axis A and stop rotating axis A when the rotation time of axis A reaches the first set threshold. Use the trigger probe to measure the coordinates of each measurement reference point at each measurement position in sequence, and calculate the center coordinates of the standard ball at each measurement position in the cycle stage. The axis rotation cycle phase refers to the state when axis A is running normally. S4. Calculate the thermal deformation value of the A-axis during the rotation phase based on the initial center coordinates of the standard spheres at each measurement position when the machine is turned on and the center coordinates of the standard spheres at each measurement position during the circulation phase. S5. Determine whether the thermal deformation value of the A-axis during the shaft circulation stage has reached the cooling stage condition. If yes, proceed to step S6; otherwise, proceed to step S3. S6. When entering the cooling stage, stop rotating the A-axis. When the time elapsed since entering the cooling stage reaches the second set threshold, use the trigger probe to measure the coordinates of each measurement reference point at each measurement position in sequence, and calculate the center coordinates of the standard sphere at each measurement position during the cooling stage. The cooling phase refers to the state when the A-axis is not running. S7. Calculate the thermal deformation value of the A-axis during the cooling stage based on the initial center coordinates of the standard spheres at each measurement position when the machine is turned on and the center coordinates of the standard spheres at each measurement position during the cooling stage. S8. Determine whether the thermal deformation value of the A-axis during the cooling stage meets the interruption measurement condition. If yes, proceed to the interruption measurement stage and obtain the thermal deformation value detection result of the A-axis. Otherwise, execute step S6.

2. The method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe according to claim 1, characterized in that, Step S1 specifically includes: S11. Preset four measurement reference points on the standard ball and install the standard ball on the plane of the five-axis machine tool table, keeping the installation position of the standard ball away from the center of the five-axis machine tool table and the line connecting the standard ball and the center of the five-axis machine tool table parallel to the X-axis direction. The four measurement reference points are the first measurement reference point, the second measurement reference point, the third measurement reference point, and the fourth measurement reference point. S12. Based on the travel of the A-axis of the five-axis machine tool, preset three measurement positions; The three measurement positions are the first measurement position, the second measurement position, and the third measurement position. If the travel of the A-axis of the five-axis machine tool is less than -60° or 60°, then three measurement positions are selected at equal intervals according to the actual travel of the A-axis of the five-axis machine tool, and the first measurement position and the third measurement position are symmetrically distributed. If the travel of the A-axis of the five-axis machine tool is greater than -60° or 60°, then the A-axis of the five-axis machine tool is set at the positions of -60°, 0°, and 60° as the first measurement position, the second measurement position, and the third measurement position, respectively. S13. Install the trigger probe onto the spindle above the five-axis machine tool table, and use the spindle to drive the trigger probe to perform linear motion.

3. The method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe according to claim 2, characterized in that, Step S2 specifically includes: When the five-axis machine tool is turned on, the machine tool table rotates along the A-axis. At the same time, the spindle of the five-axis machine tool drives the trigger probe to make linear motion along the X-axis, Y-axis or Z-axis. By contacting the measurement reference points of the standard ball at each measurement position in sequence, the coordinates of each measurement reference point are obtained, and the initial center coordinates of the standard ball at each measurement position are calculated when the machine is turned on.

4. The method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe according to claim 3, characterized in that, The condition for entering the cooling stage in step S6 is that the maximum difference in thermal deformation in the five directions of X-axis, Y-axis, Z-axis, A-axis, B-axis or X-axis, Y-axis, Z-axis, A-axis, C-axis in the last hour of the shaft circulation stage is less than 15% of that in the first hour of the shaft circulation stage.

5. The method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe according to claim 4, characterized in that, The condition for entering the interrupted measurement stage in step S8 is that the maximum difference in thermal deformation in the five directions of X-axis, Y-axis, Z-axis, A-axis, B-axis or X-axis, Y-axis, Z-axis, A-axis, C-axis in the last hour of the cooling stage is less than 15% of that in the first hour of the cooling stage.

6. The method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe according to claim 5, characterized in that, The calculation formulas for the initial center coordinates of the standard spheres at each measurement position during power-on in step S2, the center coordinates of the standard spheres at each measurement position during the looping phase in step S3, and the center coordinates of the standard spheres at each measurement position during the cooling phase in step S6 are the same and are as follows: Among them, t i Let A represent the i-th measurement time. mi B mi Let Q1 represent the different intermediate matrices at measurement position m at the i-th measurement time. xmi Q2 xmi Q3 xmi Q4 xmi Q1 represents the coordinates of the first, second, third, and fourth measurement reference points at measurement position m at the i-th measurement time, along the X-axis. ymi Q2 ymi Q3 ymi Q4 ymi Q1 represents the coordinates of the first, second, third, and fourth measurement reference points at measurement position m at the i-th measurement time, along the Y-axis. zmi Q2 zmi Q3 zmi Q4 zmi Q1 represents the coordinates of the first, second, third, and fourth measurement reference points at measurement position m at the i-th measurement time, along the Z-axis. x1i Q2 x2i Q3 x3i Q4 x4i Let Q1 represent the coordinates of the first measurement reference point at the first measurement position, the second measurement reference point at the second measurement position, the third measurement reference point at the third measurement position, and the fourth measurement reference point at the fourth measurement position at the i-th measurement time, respectively, along the X-axis. y1i Q2 y2i Q3 y3i Q4 y4i Let Q1 represent the coordinates of the first measurement reference point at the first measurement position, the second measurement reference point at the second measurement position, the third measurement reference point at the third measurement position, and the fourth measurement reference point at the fourth measurement position at the i-th measurement time, respectively, along the Y-axis. z1i Q2 z2i Q3 z3i Q4 z4i Let P represent the coordinates of the first measurement reference point at the first measurement position, the second measurement reference point at the second measurement position, the third measurement reference point at the third measurement position, and the fourth measurement reference point at the fourth measurement position at the i-th measurement time, respectively, along the Z-axis. xmi P ymi P zmi Let X, Y, and Z represent the coordinates of the center of the standard sphere at measurement position m at the i-th measurement time, in the X, Y, and Z directions, respectively.

7. The method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe according to claim 6, characterized in that, The thermal deformation value of the A-axis in the rotation cycle stage in step S4 and the thermal deformation value of the A-axis in the cooling stage in step S7 both include linear displacement thermal deformation in the X-axis, Y-axis and Z-axis directions, angular displacement thermal deformation in the A-axis direction, angular displacement thermal deformation in the B-axis direction or angular displacement thermal deformation in the C-axis direction.

8. The method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe according to claim 7, characterized in that, The formulas for calculating linear displacement thermal deformation in the X, Y, and Z axis directions are as follows: Where t0 represents the initial time. P represents the linear displacement thermal deformation values ​​of axis A in the X, Y, and Z directions at the i-th measurement time, respectively. x1i P y1i P z1i Let P represent the coordinates of the center of the standard sphere at the first measurement position at the i-th measurement time along the X, Y, and Z axes, respectively. x3i P y3i P z3i Let P represent the coordinates of the center of the standard sphere at the third measurement position at the i-th measurement time along the X, Y, and Z axes, respectively. 0 x1 P 0 y1 P 0 z1 Let P represent the coordinates of the initial center of the standard sphere at the first measurement position along the X, Y, and Z axes, respectively. 0 x3 P 0 y3 P 0 z3 These represent the coordinates of the initial center of the standard sphere at the third measurement position in the X, Y, and Z axes, respectively.

9. The method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe according to claim 8, characterized in that, The formula for calculating the angular displacement thermal deformation in the A-axis direction is: in, Let l represent the angular displacement thermal deformation value of the A-axis in the A-axis direction at the i-th measurement moment, and l represent the Y-axis distance between the centers of the standard spheres at the first and third measurement positions.

10. The method for detecting thermal deformation of the A-axis of a five-axis machine tool based on a trigger-type probe according to claim 9, characterized in that, The formulas for calculating angular displacement thermal deformation in the B-axis direction or angular displacement thermal deformation in the C-axis direction are as follows: in, This represents the angular displacement thermal deformation value of axis A in the direction of axis B at the i-th measurement moment. P represents the angular displacement thermal deformation value of axis A in the direction of axis C at the i-th measurement moment. 0 x2 P represents the coordinates of the initial center of the standard sphere at the second measurement position along the X-axis. 0 y3 This represents the coordinates of the initial center of the standard sphere at the third measurement position along the Y-axis.

Images