Design method for electron beam welding process of irregular rotation structure

Abstract

The invention provides an electron beam welding process design method of an irregular rotation structure, which comprises the following specific steps of: 1, determining the welding posture of a welded part, and establishing an operation coordinate system; step 2, determining discrete points on the surface of a to-be-welded seam: outputting coordinates of discrete points of an inner contour line and coordinates of discrete points of an outer contour line according to the length of the welding seam; 3, electron beam welding parameters are determined, specifically, the width of a to-be-welded surface and the vertical distance between an electron gun and the to-be-welded surface are calculated, and according to the calculation result, the welding beam value needed by the thickness of a welding cross section, the focusing current value needed by the electron gun focusing to the height of the welded surface and the axial displacement of each discrete point on a horizontal coordinate axis during electron beam welding are determined; and fourthly, an electron beam welding process program is determined. According to the method, welding parameters are accurately controlled, the number of segmented welding times is reduced, and the effects of enhancing the welding quality and improving the production efficiency are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electron beam welding, and particularly relates to a method for designing an electron beam welding process for an irregular rotary structure. Background Art

[0002] A certain welded part has a large spatial structure size. The weld position is in the middle of the component, and the surface to be welded is a spatial curved surface. The thickness of the welding part and the height of the surface to be welded can only be roughly measured by measuring tools. The existing method can only perform multi-segment welding through a segmented welding method of linear interpolation and rough measurement of the thickness and welding height to be welded. The weld of the special-shaped curved surface structure is divided into multiple segments, and then each segment is welded separately. Although this welding method can achieve the connection of the entire weld after multiple rounds of adjustment, it involves multiple start and stop processes, which easily cause the quality of the weld in the start and stop areas to decline. Multi-segment welding involves multiple welding program programming, with extremely low efficiency. In addition, using measuring tools to measure the thickness and height to be welded at multiple positions results in low accuracy. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for designing an electron beam welding process for an irregular rotary structure, which realizes precise control of welding parameters, reduces the number of segmented weldings, and achieves the effects of enhancing welding quality and improving production efficiency.

[0004] The technical solution of the present invention is that the specific steps of a method for designing an electron beam welding process for an irregular rotary structure are as follows:

[0005] Step 1, determine the welding posture of the welded part and establish an operation coordinate system:

[0006] Determine the clamping orientation of the welded part during welding and the height of the origin of the electron gun coordinate system relative to the welded part during welding; the surface to be welded is placed in a vertical state as the clamping orientation; the origin of the electron gun coordinate system is opposite to the highest point of the outer surface weld of the welded part. This position is the position of the electron gun, and this point is marked;

[0007] Operation coordinate system: The coordinate origin of the operation coordinate system is the center point of the electron gun installation, and the plane where the horizontal coordinate axis and the vertical coordinate axis are located is parallel to the welded cross-section;

[0008] According to the welding posture of the welded part and the operation coordinate system, establish the positional relationship between the three-dimensional model of the welded part and the absolute coordinate system in the UG software;

[0009] Step 2, determine the discrete points on the surface of the weld to be made:

[0010] Perform isoparametric line discretization on the surface of the weld to be joined, that is, make multiple longitudinal sections on the surface of the weld to be joined. The multiple longitudinal sections are evenly distributed, and the intersection lines of the multiple longitudinal sections and the surface of the weld to be joined form discrete lines. The intersection points of the discrete lines and the inner and outer contours of the surface of the weld to be joined form discrete points;

[0011] Based on UG software, perform isoparametric line discretization on the cross-section to be welded according to the weld length, and output the coordinates of the discrete points of the inner contour line and the coordinates of the discrete points of the outer contour line;

[0012] Step 3, determine the electron beam welding parameters:

[0013] Calculate the width of the surface to be welded and the vertical distance from the electron gun to the surface of the weld to be joined. According to the calculation results, determine the welding beam current value required to penetrate the cross-section thickness, the focusing current value required for the electron gun to focus to the height of the weld surface, and the axial displacement of each discrete point on the horizontal coordinate axis during electron beam welding;

[0014] Step 4, determine the electron beam welding process program:

[0015] According to the axial displacement of each discrete point on the corresponding horizontal coordinate axis, the welding beam current value, and the focusing current value, determine the welding process program according to the requirements of the CNC control system of the electron beam welding machine.

[0016] The specific steps of Step 3 are as follows:

[0017] Step 1, subtract the vertical coordinate value of the discrete point on the outer contour line from the vertical coordinate value of the discrete point on the inner contour line on the same longitudinal section to obtain the thickness of the cross-section to be welded on the same longitudinal section, so as to obtain the thickness of the cross-section to be welded on all longitudinal sections;

[0018] Step 2, obtain the vertical coordinate values of all discrete points on the outer contour line, that is, obtain the distance from the electron gun to the weld surface within different longitudinal sections;

[0019] Step 3, according to the thickness of the cross-section to be welded on all longitudinal sections obtained in Step 1, match the welding beam current value required to penetrate the cross-section thickness in the welding process database according to the order of discrete points;

[0020] Step 4, according to the distance from the electron gun to the weld surface within different longitudinal sections obtained in Step 2, match the required focusing current value in the welding process database according to the order of discrete points;

[0021] Step 5, subtract the horizontal coordinate values between adjacent discrete points on the outer contour line to obtain the axial displacement of the horizontal coordinate axis during electron beam welding.

[0022] The beneficial effects of the present invention are as follows: the present invention effectively reduces the number of segmented weldings, focuses the focusing current and the welding current, can accurately match and couple with the actual state of the workpiece to be welded, improves the weld quality, effectively increases the programming efficiency of electron beam welding, reduces the welding preparation time, improves the welding qualification rate of the workpiece to be welded, and achieves the effects of improving the welding quality and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings included herein are used to provide a further understanding of the embodiments of the present invention, which form a part of the specification, are used to illustrate the embodiments of the present invention, and together with the written description are used to explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0024] Figure 1 Schematic diagram of the structure of the workpiece to be welded in an electron beam welding process design method for an irregular rotating structure of the present invention;

[0025] Figure 2 Schematic diagram of the weld cross-section in the present invention;

[0026] Figure 3 Schematic diagram of the discrete straight line in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The technical solutions of the present invention will be further described in detail below with reference to the drawings in the specification.

[0028] As Figures 1 to 3 shown, an electron beam welding process design method for an irregular rotating structure of the present invention includes the following steps:

[0029] Step 1: Determine the welding posture of the workpiece to be welded and establish an operation coordinate system:

[0030] According to the structural characteristics of the part to be welded on the workpiece to be welded, determine the clamping orientation during welding and the height of the origin of the electron gun coordinate system relative to the workpiece to be welded; when determining the clamping orientation, try to place the surface to be welded in a vertical state as much as possible; when determining the height of the origin of the electron gun coordinate system relative to the workpiece to be welded, take the highest point of the outer surface weld of the workpiece to be welded for confirmation and mark this point for subsequent use. The electron gun uses a fixed gun type welding machine.

[0031] Operation coordinate system: Determine the coordinate system according to the welding placement posture of the workpiece to be welded, with the coordinate origin being the center point of the electron gun installation, and the plane where the horizontal coordinate axis X (or coordinate axis Y) and the vertical coordinate axis Z are located being parallel to the welded cross-section.

[0032] Import the 3D model of the workpiece to be welded into the UG software, and determine the positional relationship between the 3D model of the workpiece to be welded and the absolute coordinate system in the UG software according to the welding posture of the workpiece to be welded and the positional relationship with the operation coordinate system.

[0033] Step 2: Determine the discrete points on the surface of the weld to be formed:

[0034] As Figure 2 shown, perform isoparametric line discretization on the surface of the weld to be formed, that is, make multiple longitudinal sections on the surface of the weld to be formed. The multiple longitudinal sections are evenly distributed, and the intersection lines of the multiple longitudinal sections and the surface of the weld to be formed form discrete lines. The intersection points of the discrete lines and the inner and outer contours of the surface of the weld to be formed form discrete points.

[0035] Based on the UG software, perform isoparametric line discretization on the cross-section of the weld to be formed for the model with adjusted posture according to the weld length; the discretization density of the isoparametric discrete lines needs to be determined according to the curvature of the inner and outer contour lines of the surface to be welded and the weld length, and appropriate adjustment should be made while taking into account the operation efficiency;

[0036] Based on the UG software, load the output point plug-in developed through secondary development, and output the coordinate values of the discrete points of the inner and outer contour lines of the isoparametric discrete lines of the cross-section;

[0037] Step 3: Determine the electron beam welding parameters:

[0038] Calculate the width of the surface to be welded and the vertical distance from the electron gun to the surface of the weld to be formed, and determine the welding beam current value required to penetrate the cross-section thickness, the focusing current value required for the electron gun to focus to the height of the weld surface, and the axial displacement amount during electron beam welding according to the calculation results.

[0039] Step 1: Subtract the Z-value coordinates of the discrete points on the inner and outer contour lines of the same longitudinal section from the Z-value coordinates of the discrete points on the inner contour line to obtain the thickness of the cross-section to be welded on the same longitudinal section, so as to obtain the thickness of the cross-section to be welded on all longitudinal sections;

[0040] Step 2: Obtain the distance from the electron gun to the weld surface within different longitudinal sections by taking all the Z coordinate values of the discrete points on the outer contour line;

[0041] Step 3: According to the thickness of the cross-section to be welded on all longitudinal sections obtained in Step 1, match the welding beam current value required to penetrate the cross-section thickness in the welding process database in the order of discrete points;

[0042] Step 4: According to the distance from the electron gun to the weld surface within different longitudinal sections obtained in Step 2, match the required focusing current value in the welding process database in the order of discrete points;

[0043] Step 5: Subtract the X(Y)-value coordinates between adjacent discrete points on the outer contour line to calculate the axial displacement amount of the X(Y) axis during electron beam welding;

[0044] Step 4, determine the electron beam welding process program:

[0045] According to the requirements of the CNC control system of the electron beam welder, determine the electron beam welding process program based on the X (Y) - axis displacement amounts, welding beam current values, and focusing current values corresponding to the respective discrete points.

[0046] The present invention not only ensures high - quality electron beam welding of non - regular rotary structures, but also significantly improves the welding efficiency.

Claims

1. A method for designing an electron beam welding process for an irregular rotary structure, characterized in that: The specific steps of this design method are as follows: Step 1: Determine the welding posture of the welded parts and establish an operation coordinate system: Determine the clamping orientation of the welded parts during welding and the height of the origin of the electron gun coordinate system relative to the welded parts during welding; the orientation with the surface to be welded placed vertically is the clamping orientation; the origin of the electron gun coordinate system corresponds to the highest point of the outer surface weld of the welded parts, and this position is the electron gun position, and this point is marked; Operation coordinate system: The origin of the operation coordinate system is the center point of the electron gun installation, and the plane where the horizontal coordinate axis and the vertical coordinate axis are located is parallel to the welded section; According to the welding posture of the welded parts and the operation coordinate system, establish the positional relationship between the three-dimensional model of the welded parts in the UG software and the absolute coordinate system in the UG software; Step 2: Determine the discrete points on the surface of the weld to be made: Perform isoparametric line discretization on the surface of the weld to be made, that is, make multiple longitudinal sections on the surface of the weld to be made. The multiple longitudinal sections are evenly distributed, and the intersection lines of the multiple longitudinal sections and the surface of the weld to be made form discrete lines. The intersection points of the discrete lines and the inner and outer contours of the surface of the weld to be made form discrete points; Based on the UG software, perform isoparametric line discretization on the cross-section to be welded according to the weld length, and output the coordinate values of the discrete points of the inner contour line and the coordinate values of the discrete points of the outer contour line; Step 3: Determine the electron beam welding parameters: Calculate the width of the surface to be welded, the vertical distance from the electron gun to the surface of the weld to be made, and determine the welding beam current value required to penetrate the cross-section thickness, the focusing current value required for the electron gun to focus to the height of the weld surface, and the axial displacement of each discrete point on the horizontal coordinate axis during electron beam welding according to the calculation results; Step 4: Determine the electron beam welding process program: According to the axial displacement of each discrete point on the corresponding horizontal coordinate axis, the welding beam current value, and the focusing current value, determine the welding process program according to the requirements of the CNC control system of the electron beam welding machine.

2. The design method of the electron beam welding process for an irregular rotary structure according to claim 1, wherein: The specific steps of Step 3 are as follows: Step 1: Subtract the vertical coordinate value of the discrete point on the outer contour line and the vertical coordinate value of the discrete point on the inner contour line on the same longitudinal section to obtain the thickness of the cross-section to be welded on the same longitudinal section, so as to obtain the thickness of the cross-section to be welded on all longitudinal sections; Step 2: Obtain the vertical coordinate values of all discrete points on the outer contour line, that is, obtain the distance from the electron gun to the weld surface in different longitudinal sections; Step 3: According to the thickness of the cross-section to be welded on all longitudinal sections obtained in Step 1, match the welding beam current value required to penetrate the cross-section thickness in the welding process database according to the order of discrete points; Step 4: According to the distance from the electron gun to the weld surface in different longitudinal sections obtained in Step 2, match the required focusing current value in the welding process database according to the order of discrete points; Step 5: Subtract the horizontal coordinate values between adjacent discrete points on the outer contour line to obtain the axial displacement of the horizontal coordinate axis during electron beam welding.

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