Path compensation method for end socket machining

Abstract

The invention discloses a path compensation method for seal head machining, which comprises the following steps: after a numerical control laser cutting machine tool is started, firstly carrying out seal head centering, and finding out a neutral axis A'o and a vertex position P'o of a seal head; the center axis Ao and the fixed point position Po of the real object coincide with the neutral axis A'o and the vertex position P'o of the machine tool mathematical model; searching the position Cia of the center of a certain cutting circle on the surface of the real object; cia is used as the center of a new circle, and coordinate transformation is carried out on a cutting circle track in the modulus; the new track of the cutting circle is converted into a cutting program to be transmitted to the numerical control machine tool; and completing compensation. According to the path compensation method for seal head machining, deviation compensation between a digital model and a real object of a seal head part is achieved, the risk that a cutting head collides with the real object is avoided, the safety coefficient during machining is improved, and compared with a manual compensation mode, the machining efficiency can be greatly improved.

Description

Technical Field

[0001] The invention relates to end cap processing, and in particular to a path compensation method for end cap processing. Background Art

[0002] The surface of the head-type parts is a spatial curve, and at the same time it has geometric symmetry and a relatively simple structure; for example, the outer surface curve of the head part takes the vertical Z axis as the rotation center, and an elliptical curve is used as the generatrix to rotate about the Z axis, which is the outer surface curve of the head.

[0003] The forming process of the head usually adopts spinning, stamping and other methods, but there are certain shape errors. At present, there are relevant national standards to constrain this error in the industry's production and processing. When this error is within a certain range, it is allowed and will not affect the use effect, so it will not be treated as a quality defect. However, when CNC machine tools are used for processing, it will cause contradictions. Currently, CNC laser cutting machines are more widely used for processing heads. The single-axis control accuracy of CNC machine tools can reach the micron level (0.001mm), and the comprehensive motion control accuracy can reach the silk level (0.01mm), but the size deviation of the head is allowed to reach the millimeter level.

[0004] However, laser processing is very sensitive to the distance between the focus and the workpiece. The trajectory of the CNC system's processing of the physical head is based on the digital model. If the deviation between the digital model and the physical object is too large, it will cause processing failure. For example, when the physical value is greater than the digital model value, the cutting head will be at risk of colliding with the physical object. When the physical value is less than the digital model value, the processing focus will not be in the appropriate position, resulting in cutting defects or cutting failures. Therefore, a method is needed to compensate for the error between the physical object and the digital model. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a path compensation method for head processing which can solve the deviation compensation between the digital model and the real object of head parts.

[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0007] A path compensation method for head processing comprises the following steps:

[0008] S1. Start the CNC laser cutting machine;

[0009] S2. Center the head and find the neutral axis A'o and vertex position P'o of the head;

[0010] S3. Align the center axis Ao and the fixed point position Po of the physical object with the neutral axis A'o and the vertex position P'o of the machine tool digital model;

[0011] S4. Find the position Cia of the center of a cutting circle on the surface of the object;

[0012] S5. Taking Cia as the center of the new circle, coordinate transformation is performed on the cutting circle trajectory in the module;

[0013] S6. The new trajectory of the cutting circle is converted into a cutting program and transmitted to the CNC machine tool;

[0014] S7. Compensation is completed.

[0015] Furthermore, the CNC laser cutting machine tool in step S1 is a five-axis interpolation motion machine tool, which includes an X-axis, a Y-axis, a Z-axis, an A-axis, and a B-axis, wherein the X-axis, the Y-axis, and the Z-axis are the main motion axes of the machine tool, the XY axes constitute a horizontal plane space, the Z axis moves up and down, the AB axis is the rotation axis of the cutting head, the A axis rotates with the X axis as the center, and the B axis is the rotation center of the Y axis.

[0016] Furthermore, the five-axis interpolation motion machine tool includes a cutting head height detection device, a cutting head height compensation device, a five-axis CNC system, data processing software and three-dimensional trajectory generation software. The cutting head height detection device uses a capacitive sensor, which is integrated in the cutting head.

[0017] Furthermore, the centering of the end cap in step S2 is based on the principle of cutting head height detection, and the central axis A'o and the vertex P'o of the end cap are calculated after detection.

[0018] Furthermore, the step S4 is specifically as follows: firstly, one of the cutting circles is selected, and after the machine tool obtains the center point position Ci on the surface of the cutting circle, the cutting head nozzle is moved to the corresponding position, and the cutting head nozzle performs a slow circular motion until the cutting head nozzle touches the outer surface of the physical workpiece, thereby obtaining the coordinate value of Cia.

[0019] Furthermore, the step S5 is specifically to use the rotation angle of the cutting head nozzle as a compensation parameter in the data processing software to process the entire set of trajectory coordinates on the digital model, and to perform coordinate conversion on the cutting circle trajectory in the digital model.

[0020] Compared with the prior art, the advantages of the present invention are as follows: this path compensation method for head processing solves the deviation compensation between the digital model and the real object of head parts. There is no risk of collision between the cutting head and the real object, which improves the safety factor during processing and can greatly improve the processing efficiency compared with manual compensation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a schematic flow chart of a path compensation method for head processing of the present invention;

[0023] Figure 2 It is a schematic diagram of the workpiece placement space in a path compensation method for end cap processing of the present invention;

[0024] Figure 3 It is a schematic diagram of the positions of various detection points in a path compensation method for end cap processing of the present invention;

[0025] Figure 4 It is a schematic diagram of compensation trajectory of a path compensation method for head processing of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but only represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it is not necessary to further define and explain it in the subsequent drawings. In the description of the embodiments of the present invention, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0028] In addition, the terms "horizontal" and "vertical" do not mean that the components must be absolutely horizontal or vertical, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure or component must be completely horizontal, but can be slightly tilted.

[0029] In the description of the embodiments of the present invention, "plurality" means at least 2.

[0030] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Example

[0032] Please refer to the instruction manual Figure 1 As shown in the instruction manual, Figure 1 The figure shows a processing flow diagram of a path compensation method for head processing of the present invention. The path compensation method for head processing of the present invention is used for the processing of head parts, and mainly utilizes a CNC laser cutting machine tool. The CNC laser cutting machine tool is a five-axis interpolation motion machine tool. The five-axis interpolation motion machine tool includes an X-axis, a Y-axis, a Z-axis, an A-axis, and a B-axis, wherein the X-axis, the Y-axis, and the Z-axis are the main motion axes of the machine tool, the XY axes constitute a horizontal plane space, the Z-axis moves up and down, the AB axes are the rotation axes of the cutting head, the A axis rotates with the X-axis as the center, and the B axis is the Y-axis rotation center; in addition, the five-axis interpolation motion machine tool includes a cutting head height detection device, a cutting head height compensation device, a five-axis CNC system, data processing software, and a three-dimensional trajectory generation software.

[0033] The cutting head height detection device uses a capacitive sensor, which is integrated into the cutting head. The nozzle of the cutting head is the detection end. The position between the nozzle vertex and the workpiece is different, and the feedback capacitance value is different. By processing and calculating the capacitance value, the position distance between the nozzle and the workpiece is corresponding to realize the height detection function.

[0034] The cutting head height compensation device mainly realizes the small range movement of the cutting head on its own central axis. When the compensation device takes effect, the movement of the cutting head is that the cutting head moves on its own central axis, and the XYZAB axes can remain stationary; the cutting head height compensation device is composed of guide rails, sliders, lead screws, servo motors, servo drives, PLC control and other functional components. Like the existing cutting head height compensation device, the function of the cutting head height compensation device is that when the cutting head is adjusted within a small distance, there will be no machine tool jitter. It can play a role in surface detection or collision detection. The data generated during the actual measurement process can be automatically provided to the data processing software through the CNC system to participate in data compensation.

[0035] The five-axis CNC system, because the curve of the processing object has the characteristics of a spatial curve, the CNC system used needs to be able to realize five-axis interpolation motion control, and the CNC system needs to have the ability to communicate data with external software.

[0036] The data processing software can read the digital model trajectory of the parts generated by the three-dimensional trajectory generation software, and can communicate with the machine tool, that is, the data collected by the machine tool can be transmitted to the data processing software, the digital model trajectory of the parts can be converted into coordinates, and the modified data can be transmitted to the machine tool CNC system for use.

[0037] Three-dimensional trajectory generation software, this type of software can use mature commercial software, and its main function is to convert the digital model of the parts designed by the design software into a walking trajectory that can be read and used by CNC machine tools.

[0038] The specific working mode of this path compensation method for head processing is as follows:

[0039] Step S1: start the CNC laser cutting machine;

[0040] Step S2: Find the neutral axis A'o and vertex position P'o of the head; specifically, Figure 2 As shown, first set a suitable centering diameter according to the diameter of the workpiece, for example, 50% of the diameter. According to the cutting head height detection principle, when the cutting head nozzle and the workpiece reach a certain height, it means that the workpiece surface is detected. The coordinate values ​​of the four points on the detection circle are obtained in sequence: P1 (x1, y1, z1), P2 (x2, y2, z2), P3 (x3, y3, z3), P4 (x4, y4, z4) and the coordinate value of the vertex of the head P'o (x5, y5, z5); the detection circle is a horizontal circle, so the Z-axis values ​​of the four points are equal, that is, z1 = z2 = z3 = z4; after completing the detection, calculate the center axis A'o and the vertex P'o of the head;

[0041] in:

[0042] x5=(x2+x4) / 2,y5=(y1+y2) / 2

[0043] z5 is the measured value;

[0044] Step S3: aligning the central axis Ao and the fixed point position Po of the physical object with the neutral axis A'o and the vertex position P'o of the machine tool digital model; specifically, during the coordinate conversion, the central axis Ao and the vertex Po in the digital model are moved to A'o and P'o, and this process can be completed in the numerical control system;

[0045] Step S4: Find the position Cia of the center of a cutting circle on the surface of the object; specifically, Figure 3 As shown, one of the cutting circles is selected, and the machine tool obtains the center point position Ci on the surface of the cutting circle and moves the cutting head nozzle to the corresponding position. When approaching quickly, it gradually approaches slowly; the reason for the slow approach is that the contour of the physical head may be larger or smaller than the value of the digital model. From a safety perspective, in order to prevent excessive collision and damage, the speed is reduced; when detecting the position of the center of the cutting circle on the physical object, the running trajectory adopted by the cutting head nozzle is as follows, with P'o as the center of the circle and the straight-line distance from Po to Ci on the digital model as the radius R, and a slow circular motion is performed until the nozzle touches the outer surface of the physical workpiece, and the coordinate value of Cia is obtained. At this time, the circular motion is completed in a vertical plane, which is perpendicular to the horizontal plane, that is, perpendicular to the plane formed by XY, so the rotation angle α = arctan ((yia-yi) / (xia-xi));

[0046] Step S5: Taking Cia as the center of the new circle, coordinate transformation is performed on the cutting circle trajectory in the digital model; specifically, the rotation angle α is used as a compensation parameter in the data processing software to process the entire set of trajectory coordinates on the digital model, and coordinate transformation is performed on the cutting circle trajectory in the digital model;

[0047] Step S5: converting the new cutting circle trajectory into a cutting program and transmitting it to the CNC machine tool; specifically, after the coordinate conversion of the cutting circle trajectory in the digital model is completed, generating the new cutting circle trajectory into a cutting program and transmitting it to the CNC machine tool;

[0048] Step S5: The compensation of the cutting circle is completed.

[0049] If there are multiple cutting holes on a head part, they are traversed and processed one by one in this way, the compensation calculation is completed, and finally a complete cutting program is generated and transmitted to the machine tool CNC system. The machine tool performs processing according to the new trajectory program.

[0050] This path compensation method for head processing solves the deviation compensation between the digital model and the actual object of head parts. There is no risk of collision between the cutting head and the actual object, which improves the safety factor during processing and can greatly improve processing efficiency compared with manual compensation methods.

[0051] It should be emphasized that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A path compensation method for head processing, characterized in that: The following steps are involved: S1. Start the CNC laser cutting machine; S2. Center the head and find the neutral axis A'o and vertex position P'o of the head; S3. Align the center axis Ao and the fixed point position Po of the physical object with the neutral axis A'o and the vertex position P'o of the machine tool digital model; S4. Find the position Cia of the center of a cutting circle on the surface of the object; S5. Taking Cia as the center of the new circle, coordinate transformation is performed on the cutting circle trajectory in the module; S6. The new trajectory of the cutting circle is converted into a cutting program and transmitted to the CNC machine tool; S7. Compensation is completed.

2. A path compensation method for head processing according to claim 1, characterized in that: The CNC laser cutting machine tool in step S1 is a five-axis interpolation motion machine tool, which includes an X-axis, a Y-axis, a Z-axis, an A-axis, and a B-axis, wherein the X-axis, the Y-axis, and the Z-axis are the main motion axes of the machine tool, the XY-axis constitutes a horizontal plane space, the Z-axis moves up and down, the AB-axis is the rotation axis of the cutting head, the A-axis rotates with the X-axis as the center, and the B-axis is the rotation center of the Y-axis.

3. A path compensation method for head processing according to claim 2, characterized in that: The five-axis interpolation motion machine tool includes a cutting head height detection device, a cutting head height compensation device, a five-axis numerical control system, data processing software and three-dimensional trajectory generation software. The cutting head height detection device adopts a capacitive sensor which is integrated in the cutting head.

4. A path compensation method for head processing according to claim 1, characterized in that: The centering of the end cap in step S2 is based on the principle of cutting head height detection, and the central axis A'o and the vertex P'o of the end cap are calculated after detection.

5. A path compensation method for head processing according to claim 1, characterized in that: Specifically, step S4 includes first selecting one of the cutting circles, and then the machine tool obtains the center point position Ci on the surface of the cutting circle and moves the cutting head nozzle to the corresponding position. The cutting head nozzle performs a slow circular motion until the cutting head nozzle touches the outer surface of the physical workpiece, and obtains the coordinate value of Cia.

6. A path compensation method for head processing according to claim 1, characterized in that: Specifically, the step S5 is to use the rotation angle of the cutting head nozzle as a compensation parameter in the data processing software to process the entire set of trajectory coordinates on the digital model, and to perform coordinate conversion on the cutting circle trajectory in the digital model.

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