A standard block and attitude adjustment method for AC turntable posture adjustment in multi-axis machining

Abstract

The present invention provides a standard block and method for testing the posture adjustment of an AC turntable for multi-axis machining. The standard block is a rectangular block with a chamfered top. The chamfered top is provided with a drilled hole for mounting a positioning pin. Several countersunk through-holes are circumferentially arranged at the center of the top of the block for connection to the turntable surface. During use, the standard block is fixedly mounted on the turntable, and a leveling meter is fixedly mounted on the Z axis. This allows the standard AC turntable's A-axis to be easily, quickly, and accurately aligned with the machine tool's X-axis, the zero-position C-axis to be aligned with the Z-axis, and the center of rotation to be determined.

Description

Technical Field

[0001] The present invention is applicable to the field of machine tool posture adjustment, and in particular relates to a posture adjustment test standard block and a posture adjustment method for a multi-axis machining AC turntable. Background Art

[0002] Modern machining demands increasingly higher precision. For multi-axis machine tools, variations in ambient temperature and the accuracy of the machine itself (such as collisions and replacement of major components) can cause deviations between the model stored in the CNC system and the actual hardware structure. These discrepancies can lead to poor workpiece machining accuracy when positioning the rotation axis. Therefore, during actual machining, multi-axis machine tools must be calibrated to improve the accuracy of the workpiece. Transforming the position and posture of the workpiece based on an AC turntable is one of the core technologies of multi-axis machining. Maintaining the A-axis of a standard AC turntable parallel to the X-axis of the machine tool, the zero-position C-axis parallel to the Z-axis, and accurately determining the center of rotation are key challenges in machine tool operation. Traditional measurement methods include ballbars, lasers, and level gauges. Regardless of the method, measuring the deviations between the A-axis, C-axis, and center of rotation is cumbersome and typically requires specialized personnel. Summary of the Invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides a standard block for adjusting the posture of an AC turntable and a posture adjustment method thereof, which can accurately adjust the posture of a multi-axis machining AC turntable.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A standard block for testing the posture adjustment of an AC turntable for multi-axis machining comprises a rectangular block; the upper corners of the block are provided with one to four chamfers; the chamfers are provided with drilled holes for mounting locating pins; and several countersunk through-holes are provided circumferentially at the center of the upper portion of the block for connection to the upper surface of the turntable. When a single locating pin is used, the pinhead has a set of coordinate values ​​at its spatial position. Rotating it 180° yields corresponding coordinate values, allowing calculation of a rotation center O. When multiple locating pins are used, the pinhead has multiple sets of coordinate values ​​at its spatial position. Rotating it 180° yields multiple sets of corresponding coordinate values. Multiple rotation centers can be calculated, and the average of these rotation centers can be used to reduce the error in the rotation center O.

[0006] Furthermore, the angle between the chamfer and the horizontal plane is about 45 degrees.

[0007] Furthermore, the accuracy of parallelism, perpendicularity, flatness and surface roughness of each face of the rectangular block is plus or minus 0.02 mm.

[0008] Furthermore, the rectangular block is a rectangular metal block, and a rust-proof layer is provided on the surface of the rectangular block.

[0009] The posture adjustment method based on the above standard block includes the following steps:

[0010] (1) Fix the standard block on the AC turntable and the level gauge on the Z axis;

[0011] (2) Operate the machine tool so that the needle of the level gauge moves left and right along the X-axis on the surface of the standard block. Observe whether the standard block is level. If it is not level, adjust the pitch of the AC turntable to make the standard block level.

[0012] (3) Operate the machine tool so that the needle of the level gauge moves back and forth along the Y-axis on the surface of the standard block, and observe whether the standard block is level from front to back. If it is not level, operate the machine tool so that the turntable rotates around the A-axis to adjust the standard to be level from front to back;

[0013] (4) Use the level gauge needle to slide across the first A-axis calibration surface of the standard block parallel to the X-axis to check whether the side surface is level front to back. If it is not level, operate the machine tool to rotate the AC turntable around the C-axis to make the side surface level front to back.

[0014] (5) Operate the machine tool and rotate the AC turntable 90 degrees around the A-axis; slide the needle of the level gauge across the second A-axis calibration surface of the standard block parallel to the X-axis to check whether the second A-axis calibration surface is horizontal. If it is not horizontal, it means that there is an intersection angle between the A-axis and the X-axis on the horizontal plane. Then reset the AC turntable to zero, rotate it 90 degrees, and measure the horizontality of this side again. Repeat this process until this side is horizontal.

[0015] (6) Rotate the AC turntable 90 degrees around the A-axis and return to the zero position. Then rotate it 90 degrees around the C-axis and check whether the upward side of the standard block is horizontal. If it is not horizontal, it means that there is a deviation between the C-axis and the Z-axis. Then further check the intersection angle. The deviation between the side and the horizontal plane is the current deviation between the C-axis and the Z-axis. If the deviation between the C-axis and the Z-axis is not within the allowable range, repeat the above steps. After several repetitions, if the deviation is still outside the allowable range, it can be considered that the deviation is either a problem with the turntable quality, a problem with the module quality, or a problem with the module installation.

[0016] (7) When the deviation between the C axis and the Z axis is within the tolerance range, further measure the rotation center; install the positioning pin to the drill hole of the standard block, return the AC turntable position to zero, measure the position P of the positioning pin by the measuring rod of the machine tool or the nozzle of the printer, and then operate the machine tool to rotate the turntable 180 degrees around the C axis. Point P reaches the symmetrical point Q around the rotation center O, so the rotation center is

[0017] O=(P+Q) / 2

[0018] (8) Reset the position of the AC turntable to zero, then rotate the AC turntable 90 degrees around the A axis, and calculate the new position that point P should reach based on the kinematic principles of the machine tool and the position of point O; then measure the actual position of point P, and compare the deviation d between the actual position and the new position. If d is within the given tolerance range, it means that the measurement of the turntable center O is accurate; if it is not within the tolerance range, it means that the position of the turntable center is not measured accurately, or there is no intersection between the A axis and the C axis when the turntable leaves the machine, that is, the AC turntable does not have a rotation center; eliminate measurement errors by repeating (7) and (8) multiple times.

[0019] Beneficial effects: The present invention overcomes the problems of low test results accuracy obtained by traditional measurement methods, complicated operation, and the operator consuming a lot of energy and taking a long time in the process of leveling the machine tool. The use of standard blocks can conveniently, quickly and accurately adjust the posture of the multi-axis machining AC turntable, accurately make the A-axis of the AC turntable parallel to the X-axis of the machine tool, and the zero-position C-axis parallel to the Z-axis, and measure the center of rotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the assembly drawing of the standard block for the AC turntable attitude adjustment test;

[0021] Figure 2 It is a structural diagram of a rectangular block;

[0022] Figure 3 It is a schematic diagram of the interior of the rectangular block;

[0023] Figure 4 This is a schematic diagram of the positioning needle;

[0024] Numbers in the figure: 1. Locating pin; 2. Standard block; 3. Drill hole; 4. Countersunk through hole; 5. Second A-axis calibration surface; 6. Locating pin positioning surface; 7. First A-axis calibration surface; 8. Horizontal calibration surface. DETAILED DESCRIPTION

[0025] The present invention will be further explained below with reference to the accompanying drawings and embodiments.

[0026] The steps for making the standard block provided by the present invention are as follows: first, take a rectangular metal block (usually an iron block) with the required length, width and height, and chamfer the corners on its upper part, which can be 1 to 4, such as Figure 1 、 2 As shown, this embodiment chamfers two diagonal corners. The angle between the chamfered surface (i.e., the locating pin positioning surface 6) and the horizontal plane is approximately 45 degrees. The chamfered area is preferably large enough to allow drilling and installation of the locating pin. There are no precision requirements for the angle or chamfered area; skilled workers can use their experience to achieve the desired functional requirements.

[0027] In the middle of the standard block 2, a countersunk through hole 4 is drilled for connecting the standard block 2 and the upper surface of the turntable. Figure 1 and 2 As shown, after chamfering and drilling, the surface of standard block 2 is finished. The six faces of standard block 2 can be divided into three groups of parallel faces. The side faces should be perpendicular to the upper and lower bases. The requirements for parallelism, perpendicularity, and surface roughness are determined by the standard designer based on the machining accuracy of the machine tool. For a five-axis FDM 3D printer, the requirements for parallelism, perpendicularity, and surface roughness are set to plus or minus 0.02 mm.

[0028] After the standard block 2 is processed on the milling machine, the surface can be subjected to rust-proof treatment, but it is necessary to ensure that the parallelism, perpendicularity and surface roughness of the surface after the rust-proof treatment still meet the precision requirements.

[0029] When using this standard block to calibrate the AC turntable shown in the figure, the operating steps are as follows:

[0030] (1) Fix the standard block on the turntable and fix the leveling meter on the Z axis.

[0031] (2) Operate the machine tool so that the needle of the level gauge moves left and right along the X-axis on the surface of the standard block. Observe whether the standard block is level left and right. If it is not level, adjust the pitch of the AC turntable to make the standard block level.

[0032] (3) Operate the machine tool so that the needle of the level gauge moves back and forth along the Y-axis on the surface of the standard block, and observe whether the standard block is level front to back. If it is not level, operate the machine tool so that the turntable rotates around the A-axis to adjust the standard to be level front to back.

[0033] (4) Use the level gauge needle to slide across the first A-axis calibration surface 7 of the standard block parallel to the X-axis to check whether the side surface is level from front to back. If it is not level, operate the machine tool and rotate the turntable around the C-axis to make the side surface level from front to back.

[0034] (5) Operate the machine tool to rotate the turntable 90 degrees around the A-axis. Slide the needle of the level gauge across the second A-axis calibration surface 5 of the standard block parallel to the X-axis to check whether the second A-axis calibration surface 5 is horizontal. If it is not horizontal, it means that there is an intersection angle between the A-axis and the X-axis on the horizontal plane. Then, reset the turntable to zero, rotate it 90 degrees, and measure the horizontality of this side again. Repeat this process until this side is horizontal.

[0035] (6) Rotate the turntable 90 degrees around the A-axis and return to the zero position. Then rotate it 90 degrees around the C-axis and check whether the upward side of the standard block is horizontal. If it is not horizontal, it means that there is a deviation between the C-axis and the Z-axis. Then further check the intersection angle. The deviation between the side and the horizontal plane is the current deviation between the C-axis and the Z-axis. This deviation may be a problem with the turntable quality, the module quality, or the module installation.

[0036] (7) When the deviation between the C-axis and the Z-axis is within the tolerance range, further measure the rotation center. Install the positioning pin to the standard block and return the turntable to zero position, as shown in Figure 3. Measure the position P of the positioning pin using the measuring rod of the machine tool or the nozzle of the printer. Then operate the machine tool to rotate the turntable 180 degrees around the C-axis. Point P reaches the symmetrical point Q around the rotation center O, so the rotation center is

[0037] O=(P+Q) / 2

[0038] (8) Return the turntable to zero position, then rotate the turntable 90 degrees around the A axis. Calculate the new position that point P should reach based on the kinematics of the machine tool and the position of point O. Then measure the actual position of point P and compare the deviation d between the actual position and the new position. If d is within the given tolerance range, it means that the measurement of the turntable center O is accurate. If it is not within the tolerance range, it means that either the position of the turntable center is not measured accurately, or there is no intersection between the A axis and the C axis when the turntable is out of the machine, that is, the turntable does not have a rotation center. Repeat (7) and (8) multiple times to eliminate measurement errors.

Claims

1. The posture adjustment method based on the posture adjustment test standard block for multi-axis machining AC turntable is characterized by: The standard block is a rectangular block; the corners of the upper part of the rectangular block are provided with 1 to 4 chamfers; the chamfers are provided with drill holes for installing positioning pins; the upper center position of the rectangular block is provided with a plurality of countersunk through holes for connecting with the upper surface of the turntable; The posture adjustment method comprises the following steps: (1) Fix the standard block on the AC turntable and the level gauge on the Z axis; (2) Operate the machine tool so that the needle of the level gauge moves left and right along the X-axis on the surface of the standard block. Observe whether the standard block is level. If it is not level, adjust the pitch of the AC turntable to make the standard block level. (3) Operate the machine tool so that the needle of the level gauge moves back and forth along the Y-axis on the surface of the standard block, and observe whether the standard block is level from front to back. If it is not level, operate the machine tool so that the turntable rotates around the A-axis to adjust the standard block to be level from front to back; (4) Use the level gauge needle to slide across the first A-axis calibration surface of the standard block parallel to the X-axis to check whether the side surface is level front to back. If it is not level, operate the machine tool to rotate the AC turntable around the C-axis to make the side surface level front to back; (5) Operate the machine tool and rotate the AC turntable 90 degrees around the A-axis; slide the needle of the level gauge across the second A-axis calibration surface of the standard block parallel to the X-axis to check whether the second A-axis calibration surface is horizontal. If it is not horizontal, it means that there is an intersection angle between the A-axis and the X-axis on the horizontal plane. Then reset the AC turntable to zero, rotate it 90 degrees, and measure the horizontality of this side again. Repeat this process until this side is horizontal.

2. The posture adjustment method according to claim 1, characterized in that: The angle between the chamfer and the horizontal plane is 45 degrees.

3. The posture adjustment method according to claim 1, characterized in that: The accuracy of parallelism, perpendicularity, flatness and surface roughness of each face of the rectangular block is plus or minus 0.02 mm.

4. The posture adjustment method according to claim 1, characterized in that: The rectangular block is a rectangular metal block, and a rust-proof layer is provided on the surface of the rectangular block.

5. The posture adjustment method according to claim 1, characterized in that: The posture adjustment method further comprises the following steps: (6) Rotate the AC turntable 90 degrees around the A-axis and return to the zero position, then rotate it 90 degrees around the C-axis to check whether the upward side of the standard block is horizontal. If it is not horizontal, it means that there is a deviation between the C-axis and the Z-axis. Then further check the intersection angle. The deviation between the side and the horizontal plane is the current deviation between the C-axis and the Z-axis.

6. The posture adjustment method according to claim 5, characterized in that: The posture adjustment method further comprises the following steps: (7) When the deviation between the C-axis and the Z-axis is within the tolerance range, the rotation center is further measured; the positioning pin is installed in the drilled hole of the standard block, the AC turntable position is reset to zero, and the position P of the positioning pin is measured by the measuring rod of the machine tool. Then the machine tool is operated to rotate the turntable 180 degrees around the C-axis. Point P reaches the symmetrical point Q around the rotation center O, so the rotation center is O=(P+Q) / 2 (8) Reset the position of the AC turntable to zero, then rotate the AC turntable 90 degrees around the A axis, and calculate the new position that point P should reach based on the kinematic principles of the machine tool and the position of point O; then measure the actual position of point P, and compare the deviation d between the actual position and the new position. If d is within the given tolerance range, it means that the measurement of the turntable center O is accurate; if it is not within the tolerance range, it means that the position of the turntable center is not measured accurately, or there is no intersection between the A axis and the C axis when the turntable leaves the machine, that is, the AC turntable does not have a rotation center; eliminate measurement errors by repeating (7) and (8) multiple times.

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