TWI766781B - A precision machining compensation method for finding non-symmetric edge - Google Patents

Abstract

The method of present invention comprises: a model constructing step, a target generating step, a mold placing step, a mold measuring step, a deviation acquiring step and a parameter acquiring step. Wherein a bounding box and a plurality of simulated boundary points are generated on a 3D model by an electronic device and the simulated boundary points contacts the bounding box and the 3D model; a physical mold are touched by a contacting probe to generate a plurality of contacting points after a precision processing machine receives the simulated boundary points, so that a simulated corner point and a deviation value are calculated from the contacting points. The contact probe of the precision processing machine will contact the physical mold several times according to the deviation value and the simulated boundary points, so as a center point of the physical mold is calculated by the precision processing machine. Furthermore, a plurality of calculating corner points are calculated according to the simulated corner points and the bounding box by precision processing machine.

Description

Asymmetric Edge-finding Compensation Method for Precision Machining

The invention relates to an edge-finding method for precise automatic machining, in particular to a coordinate correction method for edge-finding an asymmetric mold before electrical discharge machining.

Traditional object processing technologies mostly use mechanical processing methods such as lathes, milling machines, drilling machines, planers or grinders. However, when product specifications are required to be precise, the production equipment limitations for product processing will be greatly increased. In addition to product precision in most industries, production automation is also the trend of future processing and production equipment.

Conventional precision operations are mostly electrical discharge machining (EDM) using non-traditional cutting methods. EDM mainly uses electrodes that are very close to the workpiece to apply a voltage to generate spark discharges, and use this phenomenon. The high temperature generated when it occurs is used to melt and cut the workpiece, so as to achieve precision machining of high-hardness materials.

However, the main factors affecting the precision of electric discharge machining lie in the selection of actual machining parameters and the correction of coordinate errors. The actual machining of the object is based on the electrode size, workpiece material, surface thickness and other conditions as well as the operator's experience. EDM parameters used (discharge waveform, voltage, servo parameters, ... etc.).

In addition, in order to improve the accuracy and precision of machining, it is necessary to confirm the coordinate setting of the tool origin to the workpiece edge before cutting by the electric discharge machine. Therefore, an edge finding operation is usually required to correct the error value.

The traditional edge-finding correction operation is to move the probe for edge-finding to touch the square jig on the worktable, so as to obtain a moving distance to obtain the error value. The movement of the traditional probe is firstly driven by the machine tool to rapidly feed the probe towards the square fixture, so that the probe stops close to the edge of the square mold, and then fine-tunes it through the manual handwheel to make the probe touch Go to the square jig to obtain the relevant coordinates for correction. However, in the traditional manual operation method, in addition to prolonging the error detection time, the accuracy of the detected numerical value may also be inaccurate due to manual operation, and then the wrong correction value can be obtained, which reduces the precision of the processing. , In severe cases, it will affect the yield of processed parts.

The main purpose of the present invention is to provide an automatic edge-finding correction method for a machine tool, so that the edge-finding work of an asymmetric mold can be completed quickly, so that the machining error value is automatically corrected, thereby saving processing time and reducing the occurrence of errors.

The secondary purpose of the present invention is to use the 3D model of the electronic device and the contact ball probe of the precision machining machine to detect the error value, whether it is the overall correction data of the whole 3D model or the local correction data of a part of the 3D model. It can be selected according to the needs, and the on-machine correction of the precision machining machine or the external correction of the CMM can be used, which greatly improves the accuracy of automatic edge-finding correction.

In order to achieve the foregoing purpose, the asymmetric edge finding and correction method for precision machining of the present invention includes: a model establishment step, a target generation step, a mold placement step, a mold measurement step, an error obtaining step, a parameter obtaining step and a step. Coordinate compensation steps.

In the model building step, an electronic device obtains a 3D image file, the 3D image file includes a rectangular scale model and a 3D model, the rectangular scale model has an origin of coordinates, and the 3D model has a plurality of alignments with the rectangular scale model the model base edge.

The object generating step is to generate a bounding box and a plurality of simulated boundary points in the 3D model through the electronic device, wherein a corner of the bounding box can be selectively aligned with the coordinate origin, and the simulated boundary points must be located at the same time. Both the bounding box and the surface of this 3D model.

The mold placing step is to place a solid mold with the same shape as the 3D model on a square of a precision machining machine, and correct the position of the solid mold by the precision machining machine, so that most of the solid reference sides of the solid mold are parallel to each other. complex axes of the square.

The mold testing step is to make the precision processing machine generate a plurality of actual detection points on the outside of the physical mold according to a first safety value and a part of the simulated boundary points. The positions of the actual detection points are respectively moved to contact the physical mold, so that the precision machining machine obtains a first contact point, a second contact point and a third contact point.

The error obtaining step is for the electronic device to calculate a simulated corner point of the physical mold and a point between the simulated corner point and the coordinate according to the first contact point, the second contact point and the third contact point The error value of the origin, and a plurality of detection boundary points are calculated from the error value and the simulated boundary points; wherein, the detection boundary point is determined by a second safety value, the error value and the simulated boundary points. calculated.

The parameter obtaining step is to allow the contact ball probe of the precision machining machine to detect the solid mold according to the detection boundary points, so that the precision machining machine obtains a plurality of actual boundary points located on each surface of the solid mold, and the precision machining The machine obtains a center of the physical mold according to the actual boundary points point. Besides, the precision machining machine can also obtain the complex arithmetic corner points of the solid mold according to the simulated corner points and the bounding box.

The coordinate compensation step is for the precision machining machine to reset a machining origin according to the center point, the simulated corner point and the calculated corner points.

In a preferred embodiment, the bounding box is shaped as a maximal bounding box to enclose the entire 3D model, or a partial bounding box to enclose a partial component of the 3D model; wherein the bounding box has a bottom. surface, a top surface, a first side surface, a second side surface, a third side surface and a fourth side surface, the first side surface and the second side surface are adjacent to the coordinate origin, the The third side surface is located on the opposite side of the first side surface, and the fourth side surface is located on the opposite side of the second side surface.

The simulated boundary points include a first boundary point, a second boundary point, a third boundary point, a fourth boundary point and a fifth boundary point, the first boundary point is located on the top surface, the second boundary point The point is located on the first side surface, the third boundary point is located on the second side surface, the fourth boundary point is located on the third side surface, and the fifth boundary point is located on the fourth side surface.

The detection boundary points are calculated from the first boundary point, the second boundary point, the third boundary point, the fourth boundary point and the fifth boundary point respectively in combination with the error value; and the actual detection The point is calculated from the first boundary point, the second boundary point, and the third boundary point in combination with the first safety value.

A Z-axis coordinate of the center point is calculated by a pair of the first actual boundary point corresponding to the first boundary point and the coordinate origin, and an X-axis coordinate of the center point is calculated by a pair of the second boundary point. The second actual boundary point and a pair of fourth actual boundary points corresponding to the fourth boundary point are calculated, and a Y-axis coordinate of the center point is calculated by a pair of third actual boundary points corresponding to the third boundary point and a pair of It should be calculated from the fifth actual boundary point of the fifth boundary point.

The present invention is characterized in that the pre-correction and coordinate conversion of the precision machining machine can automatically correct the error value of machining by the method of the present invention, thereby saving machining time and reducing the occurrence of errors, and can be applied to the in-machine correction of the precision machining machine. Or the off-machine correction of CMM, which greatly improves the accuracy of automatic edge-finding correction and the convenience of use.

1: Electronic device

10: Right-angle scale type

101: The first plate

102: Second plate

11: 3D Models

111: Subject

112: Cylinder

113: Model base edge

2: Precision processing machine

20: Solid mold

201: Solid datum edge

202: Solid base edge

21: Right Angle Ruler

22: Contact Scouting

23: Center Point

3: Bounding Box

31: Top surface

32: First side surface

33: Second side surface

34: Third side surface

35: Fourth side surface

4: Simulate boundary points

41: First boundary point

42: Second boundary point

43: Third Boundary Point

44: Fourth Boundary Point

45: Fifth Boundary Point

46: Sixth Boundary Point

47: Seventh Boundary Point

48: Eighth Boundary Point

5: Actual detection point

51: The first actual detection point

52: The second actual detection point

53: The third actual detection point

61: The first point of contact

62: Second Contact Point

63: The third point of contact

7: Simulate corner points

8: Detect boundary points

81: The first detection boundary point

82: Second detection boundary point

83: The third detection boundary point

84: Fourth detection boundary point

85: Fifth detection boundary point

9: Actual boundary point

91: First actual boundary point

92: Second actual boundary point

93: Third actual boundary point

94: Fourth Practical Boundary Point

95: Fifth Actual Boundary Point

S1: Model building step

S2: target generation step

S3: Mold placement step

S4: Mold test step

S5: Error acquisition step

S6: Parameter acquisition step

S7: Coordinate compensation step

Fig. 1 is the flow chart of the asymmetric edge-finding correction method of precision machining of the present invention; Fig. 2 is the schematic diagram of the model establishment step of Fig. 1; Fig. 3A to Fig. 3C are the schematic diagrams of the first preferred embodiment of the generation step of Fig. 4A to 4B are schematic diagrams of the mold placement steps in FIG. 1; FIGS. 5A to 5C are schematic diagrams of the actual measurement steps of the mold in FIG. 1; FIGS. 6A to 6B are schematic diagrams of the error acquisition steps in FIG. 1; A schematic diagram of the obtaining step; and FIGS. 8A and 8B are schematic diagrams of a second preferred embodiment of the generating step of the icon in FIG. 1 .

For the convenience of further understanding and understanding of the structure, use and characteristics of the present invention, a preferred embodiment is given, and the detailed description is as follows in conjunction with the drawings:

The asymmetric edge-finding correction method for precision machining of the present invention is applied to an electronic device 1 installed with a 3D drawing software and a precision machining machine 2 for mold machining, so that the precision machining machine 2 can make a setting on the electronic device 1 . The model coordinate data is converted into a machining coordinate on an actual workbench. The precision machining machine 2 can be used in CNC machining, lathes, milling machines, drilling machines, grinding machines, wire cutting, electrical discharge machining, and ion cutting.

Please refer to FIG. 1 , the asymmetric edge-finding correction method of the present invention includes: a model establishment step S1, a target generation step S2, a mold placement step S3, a mold measurement step S4, an error acquisition step S5, and a parameter acquisition step S5. Step S6 and coordinate compensation step S7, wherein, the model establishment step S1, the target generation step S2 and the error acquisition step S5 are all performed on the electronic device 1, and the mold placement step S3, the mold measurement step S4 , the parameter acquisition step S6 and the coordinate compensation step S7 are both performed on the precision machining machine 2 .

Please refer to FIG. 2 , the model creation step S1 is to first draw a 3D drawing file with coordinate parameters in the 3D drawing software, and then let the electronic device 1 obtain the 3D drawing file, wherein the 3D drawing file includes a right angle A scale model 10 and a 3D model 11 . As shown in the figure, the right-angle scale model 10 has a first plate 101 and a second plate 102 extending horizontally toward the X-axis direction and the Y-axis direction, respectively, and the first plate 101 and the second plate An inner boundary point between 102 is set as the origin of a coordinate; the 3D model 11 has a main body 111 in a rectangular shape and a plurality of pillars 112 arranged at intervals on the right side of the main body 111 , wherein the main body 111 There are a plurality of model reference edges 113 in contact with the rectangular scale model 10 .

Referring to FIG. 3A , the object generation step S2 is to perform calculation on the 3D model 11 after the electronic device 1 obtains the 3D image file, so that the 3D model 11 generates a bounding box 3 , and one side of the bounding box 3 The corners are aligned to the origin of this coordinate. As shown in the figure, the bounding box 3 can be a maximum bounding box that wraps the main body 111 and the cylinders 112, so that the entire 3D model 11 is wrapped; however, this is only for the convenience of illustration, that is, the The bounding box 3 can be another local bounding box (not shown) that only covers the main body 111, so that a partial component of the 3D model 11 is covered. Besides, the partial bounding box can also be used for different 3D models. Model 11 is shaped so that all corners can be misaligned with this coordinate origin.

As shown, the bounding box 3 has a bottom surface, a top surface 31 , a first side surface 32 , a second side surface 33 , a third side surface 34 and a fourth side surface 35 . side surface 32 The second side surface 33 is adjacent to the coordinate origin, the third side surface 34 is located on the opposite side of the first side surface 32 , and the fourth side surface 35 is located on the opposite side of the second side surface 33 .

Please refer to the first preferred embodiment shown in FIG. 3B and FIG. 3C , after the bounding box 3 is generated, a plurality of simulated boundary points 4 can be automatically generated by the drawing software or manually selected by the user, wherein all simulated boundary points 4 must be It is located on both the surface of the bounding box 3 and the 3D model 11 at the same time; as shown in the figure, the simulated boundary points 4 include a first boundary point 41 , a second boundary point 42 , a third boundary point 43 , a A fourth boundary point 44 and a fifth boundary point 45, the first boundary point 41 is located on the top surface 31, the second boundary point 42 is located on the first side surface 32, the third boundary point 43 is located on the second side On the surface 33 , the fourth boundary point 44 is located on the third side surface 34 , and the fifth boundary point 45 is located on the fourth side surface 35 .

Referring to FIG. 4A, the mold placing step S3 is to place a solid mold 20 with the same shape as the 3D model 11 in the precision machining machine 2, wherein the precision machining machine 2 has a right angle 21, a calibration device ( Not shown), a contact ball 22, and the solid mold 20 is placed beside the right angle 21.

Since the physical mold 20 is placed manually or mechanically, there will be some skewed deviation. Therefore, please refer to FIG. 4B , after the physical mold 20 is placed, the precision machining machine 2 will pass through the The correcting device is used to move the position of the solid mold 20 , so that the two solid reference sides 201 and 202 of the solid mold 20 are respectively parallel to the coordinate X and Y axes of the right angle 21 .

Please refer to FIG. 5A , the mold measurement step S4 is for the precision machining machine 2 to obtain a first safety value and the first boundary point 41 , the second boundary point 42 and the third boundary adjacent to the coordinate origin Point 43, wherein the first safety value can be input at the electronic device 1, so that the first safety value and the simulated boundary points 4 are transmitted to the precision machining machine 2, or the precision machining machine 2 directly input the first safety value; then the precision machining machine 2 will follow the first safety value and the three modes The pseudo-boundary points 4 respectively generate a plurality of actual detection points 5 on the outside of the physical mold 20 , and the actual detection points 5 include a first actual detection point 51 , a second actual detection point 52 and a third actual detection point 53 .

Please refer to FIGS. 5B and 5C , the contact probe 22 of the precision machining machine 2 will first move to the position of the first actual detection point 51 , and from the first actual detection point 51 along a Z-axis direction The physical mold 20 moves linearly, and then moves to the position of the second actual detection point 52, from which the second actual detection point 52 moves linearly toward the physical mold 20 along a Y-axis direction, and finally, moves to the third actual detection point 52. The actual detection point 53 is then moved linearly toward the physical mold 20 along an X-axis direction from the third actual detection point 53 .

The precision machining machine 2 contacts the top surface 31 of the solid mold 20 in the Z-axis direction to form a first contact point 61 , and the precision machining machine 2 contacts the first side surface 32 of the solid mold 20 in the Y-axis direction to form a first contact point 61 . The second contact point 62, and the precision machining machine 2 contacts the second side surface 33 of the physical mold 20 in the X-axis direction to form a third contact point 63, so that the precision machining machine 2 obtains that the physical mold 20 is located in the actual mold 20. Multiple real coordinate point locations for the workbench.

Please refer to FIG. 6A , the error obtaining step S5 is for the electronic device 1 to obtain the coordinate data of the first contact point 61 , the second contact point 62 and the third contact point 63 generated by the precision machining machine 2 , Then, the electronic device 1 calculates a simulated corner point 7 of the physical mold 20 and an error value between the simulated corner point 7 and the coordinate origin, wherein the simulated corner point 7 is not related to the The physical mold 20 is in contact, and the error value includes an X-axis error and a Y-axis error.

Please refer to FIG. 6B , in the following, the electronic device 1 will further assign the first boundary point 41 , the second boundary point 42 , the third boundary point 43 , the fourth boundary point 44 and the fifth boundary point 45 The calculation is carried out in combination with the error value and a second safety value, so as to generate a setting distance from the physical mold 20. A first detection boundary point 81 , a second detection boundary point 82 , a third detection boundary point 83 , a fourth detection boundary point 84 and a fifth detection boundary point 85 are located.

Please refer to FIG. 7A , the parameter obtaining step S6 is for the precision machining machine 2 to obtain the first detection boundary point 81 , the second detection boundary point 82 , the third detection boundary point 83 , and the fourth detection boundary point 84 and the fifth detection boundary point 85, the first detection boundary point 81, the second detection boundary point 82, the third detection boundary point 83, and the fourth detection boundary point are sequentially detected by the contact ball 22. Point 84 and the fifth detection boundary point 85 are subjected to moving contact detection, so that each surface of the physical mold 20 generates a first actual boundary point 91, a second actual boundary point 92, a third actual boundary point 93, a A fourth actual boundary point 94 and a fifth actual boundary point 95 .

Please refer to FIG. 7B , the precision machining machine 2 will calculate the coordinate data of the X-axis, the Y-axis and the Z-axis respectively to calculate a center point 23 of the physical mold 20, wherein the Z-axis coordinate data is calculated by the The first actual boundary point 91 and the Z-axis coordinate parameters of the coordinate origin are calculated, and the Y-axis coordinate data is obtained by adding the two Y-axis coordinate parameters of the second actual boundary point 92 and the fourth actual boundary point 94. After averaging, the X-axis coordinate data is averaged by adding the two X-axis coordinate parameters of the third actual boundary point 93 and the fifth actual boundary point 95, so that the three-axis data of the center point 23 can be accurately obtained. .

Please refer to FIG. 7C . In addition, the precision machining machine 2 will automatically calculate the complex calculation corner points 71 of the physical mold 20 according to the simulated corner points 7 and the bounding box 3 , so that the calculation The corner points 71 and the simulated corner points 7 are located at the eight corner positions of the bounding box 3 respectively.

Finally, the coordinate compensation step S7 is for the precision machining machine 2 to reset a machining origin (not shown) according to the center point 23 , the simulated corner points 7 and the calculated corner points 71 .

8A and 8B, in the second preferred embodiment, the difference is that the simulated boundary points 4 further include a sixth boundary point 46, a seventh boundary point 47 and an eighth boundary point 48, the Six boundary points 46 are located on the top surface 31 , the seventh boundary point 47 is located on the first side surface 32 , and the eighth boundary point 48 is located on the second side surface 33 .

The first boundary point 41 , the second boundary point 42 and the third boundary point 43 are used to generate the actual detection points 5 , and the fourth boundary point 44 , the fifth boundary point 45 , the The six boundary points 46 , the seventh boundary point 47 and the eighth boundary point 48 are used to generate the detection boundary points 8 . Unlike the first preferred embodiment, the first boundary point 41 , the second boundary point 42 and the third boundary point 43 are used for two calculations, and are respectively generated as a plurality of actual boundary points 9 and a plurality of Detect boundary point 8.

S1: Model building step

S2: target generation step

S3: Mold placement step

S4: Mold test step

S5: Error acquisition step

S6: Parameter acquisition step

S7: Coordinate compensation step

Claims (6)

An asymmetric edge-finding correction method for precision machining, comprising: a model building step, obtaining a 3D image file from an electronic device, the 3D image file including a rectangular scale model and a 3D model, the rectangular scale model has a coordinate origin point, the 3D model has a plurality of model reference edges aligned with the rectangular scale model; a target generation step generates a bounding box and a plurality of simulated boundary points in the 3D model through the electronic device, wherein the simulated boundary points are located at the same time Surfaces of both the bounding box and the 3D model, the bounding box has a bottom surface, a top surface, a first side surface, a second side surface, a third side surface and a fourth side surface, the first side surface One side surface and the second side surface are adjacent to the coordinate origin, the third side surface is located on the opposite side of the first side surface, and the fourth side surface is located on the opposite side of the second side surface; the The simulated boundary points include a first boundary point, a second boundary point, a third boundary point, a fourth boundary point and a fifth boundary point, the first boundary point is located on the top surface, and the second boundary point is located at the first side surface, the third boundary point is located on the second side surface, the fourth boundary point is located on the third side surface, the fifth boundary point is located on the fourth side surface; a mold placing step, a precision A square of the processing machine places a solid mold with the same shape as the 3D model, and the precision machining machine corrects the position of the solid mold, so that most of the solid reference sides of the solid mold are respectively parallel to the plural coordinate axes of the right angle; In a mold measurement step, the precision processing machine generates a plurality of actual detection points on the outer side of the physical mold according to a first safety value and a part of the simulated boundary points. A contact probe of the precision processing machine will be determined by The positions of the actual detection points are respectively moved to contact the physical mold, so that the precision machining machine obtains a first contact point, a second contact point and a third contact point; In an error obtaining step, the electronic device calculates a simulated corner point of the physical mold and a distance between the simulated corner point and the coordinate origin according to the first contact point, the second contact point and the third contact point The error value of the point, and a plurality of detection boundary points are calculated from the error value and the simulated boundary points, wherein the detection boundary points are determined by the first boundary point, the second boundary point, and the third boundary point. , the fourth boundary point and the fifth boundary point are calculated according to the error value respectively; and the actual detection points are calculated by the first boundary point, the second boundary point and the third boundary point respectively matching the first boundary point A safety value is calculated; and a parameter acquisition step, the contact ball probe of the precision machining machine detects the solid mold according to the detection boundary points, so that the precision machining machine obtains a plurality of parameters located on each surface of the solid mold Actual boundary points, the precision machining machine obtains a center point of the entity mold according to the actual boundary points. The asymmetric edge-finding correction method for precision machining as claimed in claim 1, wherein the bounding box is formed into a maximum bounding box to cover the entire 3D model, or a partial bounding box to cover a part of the 3D model member. The asymmetric edge-finding correction method for precision machining according to claim 1, wherein a Z-axis coordinate of the center point is calculated from a pair of the first actual boundary point corresponding to the first boundary point and the coordinate origin, An X-axis coordinate of the center point is calculated by a pair of second actual boundary points corresponding to the second boundary point and a pair of fourth actual boundary points corresponding to the fourth boundary point, and a Y-axis coordinate of the center point is calculated by a pair of third actual boundary points corresponding to the third boundary point and a pair of fifth actual boundary points corresponding to the fifth boundary point. The asymmetric edge finding correction method for precision machining as claimed in claim 1, wherein, in the parameter obtaining step, the precision machining machine obtains the complex arithmetic corner points of the solid mold according to the simulated corner points and the bounding box. The asymmetric edge-finding correction method for precision machining as claimed in claim 1, wherein, in the error obtaining step, the detection boundary point is calculated by a second safety value, the error value and the simulated boundary points out. The asymmetric edge-finding correction method for precision machining as claimed in claim 1, wherein the method further comprises a coordinate compensation step, the precision machining machine recalculates the center point, the simulated corner point and the calculated corner points Set a machining origin.

Images