Three-dimensional laser cutting method for frame with n-shaped section

Abstract

The invention discloses a three-dimensional laser cutting method for a frame with an n-shaped section. The three-dimensional laser cutting method comprises the following steps that S1, a tool is clamped; s2, a part is preliminarily clamped, and a notch theoretical line is scribed; s3, alignment is carried out; s4, the cutting of all the round holes is compiled into a subprogram, and the cutting program of each notch is compiled into different bisection subprograms; and S5, the cutting track of each subprogram is preliminarily debugged, and each subprogram is adjusted as required according to the measurement result after the first workpiece is cut. The additional shaft of the machine tool controls the rotating table to rotate in a numerical control mode, so that the tool drives the part to rotate, it is ensured that each pair of notch cutting positions are located at the lowest point of the part clamping posture, cutting head movement is simplified into four-shaft movement, and interference of a rotating shaft is avoided; a small number of attitude control points are arranged to optimize the cutting attitude, three-dimensional five-axis laser cutting of the n-shaped section frame is achieved, the programming and debugging efficiency is improved, the equipment safety is improved, and the overlap ratio of notches is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of three-dimensional laser cutting methods for frame parts, and specifically relates to a three-dimensional laser cutting method for a frame with an X-shaped cross section. Background Art

[0002] In the fields of aerospace, rail vehicles, etc., sheet metal frames or profile frames of various cross sections are often used. There is a type of frame with a cross section that is approximately in the shape of a letter "J". There are usually many pairs of through notches and round holes distributed on it. The notches are used to insert structural parts such as girders and beams. These notches usually contain several shapes and are dispersed at certain angles. The traditional notch processing method is die punching. First, the notch on one side is punched out, and then the notch on the other side is punched one by one based on the punched notch. This method has the disadvantages of low efficiency, high mold cost, and high manual labor intensity. In recent years, the three-dimensional five-axis laser cutting technology of AC swing head structure has been more and more widely used in the above fields, but the three-dimensional laser cutting of the letter "J" cross-section frame is prone to the problem of interference between the cutting head and the web and bent edge of the part. One part clamping posture is to place it upright, that is, the rotation plane of the part is parallel to the XZ plane of the machine tool. In this posture, the cutting head near the nozzle is easy to collide with the web and curved edge of the part when the five-axis linkage is used, especially when the radius of curvature of the part is small and the arc of the part is long, it is more likely to collide. In this case, cutting is almost impossible; another part clamping posture is to place it horizontally, that is, the rotation plane of the part is parallel to the XY plane of the machine tool. There are two cutting schemes. One is to cut the notch on one side first and then cut the notch on the other side. In order to prevent collision, this scheme requires artificially adding many posture control points to each notch. Programming and debugging programs take a lot of time, and due to the cumulative deviation of stress release deformation, when cutting the second side, it is easy to cause large deviation in the position of the notch on the opposite side. Another scheme is to cut pairs one by one, that is, after cutting a notch on one side, rotate the tooling 180° to drive the part to turn over, and then cut the other pair of notches on the opposite side. The tooling needs to be made relatively large, and there is also the disadvantage of long programming and debugging time. At present, there is no public technology that can better solve the above problems. Summary of the invention

[0003] The problems to be solved by the present invention are: first, to use three-dimensional laser cutting to replace the existing die punching notch method; second, to propose a programming and cutting method to reduce the interference between parts and cutting heads and improve programming and debugging efficiency. In order to solve the above technical problems, the present invention provides a three-dimensional laser cutting method for a cross-section frame.

[0004] A three-dimensional laser cutting method for a cross-section frame of an X-shaped shape comprises the following steps:

[0005] S1: Clamp the tooling onto the rotary table;

[0006] S2: Use a marking template and a marking needle to mark the theoretical notch line on the part, and then stand the part upright and clamp it on the tooling;

[0007] S3: Align the tooling and use the plane features of the tooling to center it, and determine the position of the part in the machine tool after conversion;

[0008] S4: All the circular hole cutting is compiled into one subroutine, and each notch cutting program is compiled into a different cutting subroutine. Several posture control points are set to optimize the cutting posture to prevent motion interference. The notch cutting subroutines are compiled at the lowest point of the part clamping posture.

[0009] S5: First, the cutting trajectory of each subroutine is preliminarily debugged according to the deviation between the indicator light and the marking line during the simulated cutting, and then each subroutine is debugged as needed according to the measurement results after the first piece is cut.

[0010] As a preferred embodiment, the rotary table in S1 is a CNC rotary device. When its rotation plane is parallel to the XZ plane and is in a zero position, the tooling and the rotary table can be aligned as a whole by adsorbing a dial indicator on the cutting head or using the collision monitoring function of the cutting head.

[0011] As a preferred embodiment, in S2, the cross section of the symmetry plane of the part is at the lowest point, that is, the Z-direction heights of both ends are consistent.

[0012] As a preferred method, in S3, the collision monitoring function of the cutting head or the dial indicator is used for alignment and centering, so that the rotation plane of the tooling is parallel to the XZ plane of the machine tool, and the symmetry center point of the tooling is calculated and determined, and the position of the part in the machine tool is determined after conversion.

[0013] As a preferred method, relative coordinate programming is adopted in S4 to convert the notch distribution angle into the rotation angle of each pair of notches about the symmetry plane when the arc length of the part is symmetrical about the YZ plane, and the angle required for each pair of notches to rotate from the clamping zero position state to the lowest point of the part clamping posture and the movement amount in the X and Z directions are calculated. All circular holes are compiled into a subroutine and called in the clamping zero position state. The cutting order of all notches and circular holes is symmetrical cutting from the middle of the part to both ends.

[0014] Further optimization is performed by calculating r0, the outer arc radius R of the part, and the angular distribution α of the notch on the part through the structural dimensions of the tooling and the rotary table. i Calculate the angle that the tooling should rotate around its own rotation axis after cutting each pair of notches, and the movement of the center of the i-th pair of notches in the X and Z directions Δ xi , Δ zi , after the rotation is completed, the corresponding notch cutting subprogram is called, and the program header and program tail are added to form a three-dimensional laser cutting program;

[0015] Because R, α i , r0 is known, calculate Δ according to the following formula xi , Δ zi :

[0016]

[0017] The α i is the distribution angle of the i-th pair of notches about the symmetry plane of the part, that is, the distribution angle of the notch center about the arc length symmetry plane of the part, r0 is the minimum rotation radius, r i is the rotation radius of the center of the i-th pair of notches, β i is the center distribution angle of the tooling circle of the i-th pair of notches in the clamping zero position state, l i is the moving distance of the i-th pair of notch centers in the XZ plane, Δ xi , Δ zi They are the movement of the centers of the i-th pair of notches in the X and Z directions, that is, the change of the corresponding coordinate axes in the program when the subroutine is called.

[0018] As a preferred embodiment, in S5, the clamping position of the part is slightly adjusted according to the deviation between the indicator light of the first pair of notches and the scribe line in the arc length direction of the part during the simulated cutting, so that the scribe line and the indicator light coincide with each other in the arc length direction.

[0019] Beneficial effects of the present invention:

[0020] The present invention uses the additional axis CNC control of the machine tool to rotate the rotary table, so that the tooling drives the parts to rotate, ensuring that the cutting position of each pair of notches is at the lowest point of the part clamping posture, simplifying the five-axis motion of the cutting head into four-axis motion, and avoiding the interference of the rotating axis; by setting a small number of posture control points to optimize the cutting posture, the three-dimensional five-axis laser cutting of the I-shaped cross-section frame is realized, the programming and debugging efficiency is improved, while the equipment safety is improved, and the overlap of the notches is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flow chart of the method of the present invention;

[0022] Figure 2 It is a schematic diagram of the part posture when the leftmost notch turns to the lowest point of the part clamping posture;

[0023] Figure 3 This is a schematic diagram of the posture control point settings and cutting direction of a typical notch section of a part.

[0024] Among them, 1 is the part, 2 is the notch, 3 is the round hole, 4 is the posture control point, and 5 is the cutting direction; α i is the distribution angle of the i-th pair of notches about the symmetry plane of the part; r0 is the minimum rotation radius; ri is the rotation radius of the center of the i-th pair of notches; β i is the tooling center distribution angle of the i-th pair of notches in the clamping zero position state; l i is the moving distance of the center of the i-th pair of notches in the XZ plane; Δ xi is the displacement of the center of the i-th pair of notches in the X direction; Δ zi is the displacement of the center of the i-th pair of notches in the Z direction. DETAILED DESCRIPTION

[0025] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the embodiments of the present invention are given below, and the present invention is described in detail through the embodiments. It is necessary to point out that the embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Those skilled in the art in this field can make some non-essential improvements and adjustments based on the content of the present invention.

[0026] Embodiment 1:

[0027] like Figure 1-Figure 3 As shown, a three-dimensional laser cutting method for a cross-section frame of an X-shaped shape includes the following steps:

[0028] S1: Clamp the tooling onto the rotary table;

[0029] S2: Use the marking template and the marking needle to mark the theoretical line of notch 2 on part 1, and stand part 1 upright and clamp it on the tooling;

[0030] S3: Align the tooling and use the plane features of the tooling to center it, and determine the position of part 1 in the machine tool after conversion;

[0031] S4: The cutting of all the circular holes 3 is compiled into one subroutine, and the cutting program of each notch 2 is compiled into a different cutting subroutine, and a number of posture control points 4 are set to optimize the cutting posture to prevent motion interference. The notch 2 cutting subroutine is compiled at the lowest point of the clamping posture of the part 1;

[0032] S5: First, the cutting trajectory of each subroutine is preliminarily debugged according to the deviation between the indicator light and the marking line during the simulated cutting, and then each subroutine is debugged as needed according to the measurement results after the first piece is cut.

[0033] The rotary table in S1 is a CNC rotary device. When its rotation plane is parallel to the XZ plane and is in the zero position, the tooling and the rotary table are aligned as a whole by adsorbing the dial indicator on the cutting head or using the collision monitoring function of the cutting head.

[0034] In the S2, the cross section of the symmetry plane of the part 1 is at the lowest point, that is, the heights in the Z direction of both ends are consistent.

[0035] In S3, the collision monitoring function of the cutting head or the dial indicator is used for alignment and centering, so that the rotary plane of the tooling is parallel to the XZ plane of the machine tool, and the symmetry center point of the tooling is calculated and determined, and the position of the part 1 in the machine tool is determined after conversion.

[0036] The S4 adopts the relative coordinate programming method to convert the distribution angle of the notches 2 in the drawing into the rotation angle of each pair of notches 2 about the symmetry plane when the arc length of the part 1 is symmetrical about the YZ plane. The angle required for each pair of notches 2 to rotate from the clamping zero position state to the lowest point of the clamping posture of the part 1 and the movement amount in the X and Z directions are calculated. All circular holes 3 are compiled into a subroutine and called in the clamping zero position state. The cutting order of all notches 2 and circular holes 3 is symmetrical cutting from the middle of the part 1 to both ends.

[0037] r0, the outer arc radius R of part 1 and the angular distribution α of notch 2 on part 1 calculated by the structural dimensions of the fixture and rotary table i Calculate the angle that the tooling should rotate around its own rotation axis after cutting each pair of notches 2, and the movement of the center of the i-th pair of notches 2 in the X and Z directions Δ xi , Δ zi , after the rotation is completed, the corresponding notch 2 cutting subprogram is called, and the program header and program tail are added to form a three-dimensional laser cutting program;

[0038] Because R, α i , r0 is known, calculate Δ according to the following formula xi , Δ zi :

[0039]

[0040] The α i is the distribution angle of the i-th pair of notches 2 about the symmetry plane of part 1, that is, the distribution angle of the center of notch 2 on the drawing about the arc length symmetry plane of part 1, r0 is the minimum rotation radius, r i is the rotation radius of the center of the i-th pair of notches 2, β i is the tooling center distribution angle of the i-th pair of notches 2 in the clamping zero position state, l i is the moving distance of the center of the i-th pair of notches 2 in the XZ plane, Δ xi , Δ zi They are the movement of the center of the i-th pair of notches 2 in the X and Z directions, that is, the change of the corresponding coordinate axes in the program when the subroutine is called.

[0041] In S5, the clamping position of the part 1 is slightly adjusted according to the deviation between the indicator light of the first pair of notches 2 and the scribe line in the arc length direction of the part 1 during the simulated cutting, so that the scribe line and the indicator light coincide with each other in the arc length direction.

[0042] Embodiment 2:

[0043] like Figure 1-Figure 3 As shown, a three-dimensional laser cutting method for a cross-section frame of an X-shaped shape includes the following steps:

[0044] Step 1: Clamp the tooling on the rotary table;

[0045] The rotary table is an existing device, model TK15320, which can drive the tooling to rotate around its terminal rotary axis through CNC drive when the terminal axis is in a horizontal posture;

[0046] The fixture is a symmetrical structure, and its position in the machine tool can be determined by centering. Its positioning reference is kept consistent with the design reference of the part 1 as much as possible, that is, the inner side (or outer side) of the arc of the curved edge of the part 1, and can clamp the part to drive it to rotate.

[0047] When the rotation plane of the rotary table is parallel to the XZ plane and is in the zero position, the rotation plane of the tooling can be made parallel to the XZ plane, and the tooling and the rotary table can be aligned as a whole by adsorbing a dial indicator on the cutting head or using the collision monitoring function of the cutting head;

[0048] When the rotating plane of the tooling is parallel to the XZ plane, it is helpful to save travel and improve program operation efficiency.

[0049] Step 2: Preliminarily clamp part 1, return the rotary table to zero, clamp the marking template on part 1, make the process allowances at both ends roughly equal, use a marking needle to mark the theoretical lines of notch 2 and circular hole 3 on part 1, stand part 1 upright and clamp it on the tooling, make the cross section of the symmetry plane of part 1 at the lowest point, that is, the Z-direction heights at both ends are consistent. At this time, the theoretical arc length of part 1 can be considered symmetrical about the YZ plane, and this state is the clamping zero position state.

[0050] Step 3: Align, return the cutting head to zero, move the cutting head, utilize the plane features of the tooling, use the collision monitoring function of the cutting head or the dial indicator to align and center the tooling, make the rotating plane of the tooling parallel to the XZ plane of the machine tool, and calculate and determine the symmetry center point of the tooling, and after conversion, determine the position of Part 1 in the machine tool.

[0051] Step 4: Programming. For each notch 2, three-dimensional modeling is performed separately. The sketches of notch 2 and circular hole 3 are established on the XZ plane, and the symmetric center position of notch 2 is designed to be at the lowest point of part 1. The distribution angle of circular hole 3 is converted to the distribution angle when the part is symmetrical about the YZ plane, and all circular holes 3 are built in one model. Using programming software, based on the three-dimensional model of circular hole 3 and the three-dimensional model of each notch 2, the cutting edges of circular hole 3 and notch 2 are picked up, automatic cutting trajectory is generated, and several posture control points 4 are set to optimize the program of notch 3 through cutting direction 5 to prevent motion interference, and the cutting program of each notch 2 is compiled into different cutting subprograms.

[0052] Using relative coordinate programming, the distribution angle of notch 2 in the drawing is converted into the rotation angle of each pair of notches 2 about the symmetry plane when the arc length of the part is symmetrical about the YZ plane. The angle and the movement amount in the X and Z directions required for each pair of notches 2 to rotate from the clamping zero position to the lowest point of the part clamping posture are calculated. All circular holes 3 are compiled into a subroutine and called in the clamping zero position state. The cutting order of all notches 2 and circular holes 3 is symmetrical cutting from the middle of the part to both ends.

[0053] The angle that the tooling should rotate around its own rotation axis after cutting each pair of notches 2 is calculated based on r0 obtained through calculation of the structural dimensions of the tooling and the rotary table, the outer arc radius R of part 1, and the angular distribution αi of notches 2 on part 1, as well as the movement Δxi and Δzi of the center of the i-th pair of notches in the X and Z directions are calculated. After the rotation is completed, the corresponding notch cutting subroutine is called, and the program header and program tail are added to form a three-dimensional laser cutting program.

[0054] Because R, α i , r0 is known, Δ can be calculated according to the following formula xi , Δ zi :

[0055]

[0056] In the formula, the α i is the distribution angle of the i-th pair of notches 2 about the symmetry plane of part 1, that is, the distribution angle of the center of notch 2 on the drawing about the arc length symmetry plane of part 1, r0 is the minimum rotation radius, r i is the rotation radius of the center of the i-th pair of notches 2, β i is the tooling center distribution angle of the i-th pair of notches 2 in the clamping zero position state, l i is the moving distance of the center of the i-th pair of notches 2 in the XZ plane, Δ xi , Δ zi They are the movement of the center of the i-th pair of notches 2 in the X and Z directions, that is, the change of the corresponding coordinate axes in the program when the subroutine is called.

[0057] Step 5: Simulate and debug the program. According to the deviation between the indicator light and the scribe line of the first pair of notches 2 in the simulated cutting in the arc length direction of part 1, the clamping position of part 1 is slightly adjusted to make the scribe line coincide with the indicator light in the arc length direction. First, debug the cutting trajectory of each subprogram according to the deviation between the cutting indicator light and the scribe line in the radial direction observed during the simulation, and then debug each subprogram again as needed according to the measurement results after the first piece is cut to obtain a finalized NC program.

[0058] By simulating the deviation between the indicator light and the marking, it is possible to prevent the first piece from being scrapped after being cut. After the program is debugged, there is no need to mark the subsequent parts before cutting.

[0059] It should be noted that, in order to simplify the figure, the rotary table, cutting platform, cutting head, etc. are not shown in the figure. The embodiment of the method of the present invention can convert the five-axis linkage into the four-axis linkage of XYZA. The method of the present invention is also applicable to the case where the zero position state of the clamping is + / -90° of the rotary table, that is, Figure 2 Rotate 90° counterclockwise / clockwise, and the five-axis can be converted into four-axis linkage of XYZC. When cutting each pair of notches 2, they are at the rightmost / leftmost point of the part clamping posture.

[0060] It should be noted that the embodiments described are intended to help readers understand the principles of the present invention, and it should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. A person skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical inspiration disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A three-dimensional laser cutting method for a cross-section frame, characterized in that: The steps include: S1: Clamp the tooling onto the rotary table; S2: Use a marking template and a marking needle to mark the theoretical notch line on the part, and then stand the part upright and clamp it on the tooling; S3: Align the tooling and use the plane features of the tooling to center it, and determine the position of the part in the machine tool after conversion; S4: All the circular hole cutting is compiled into one subroutine, and each notch cutting program is compiled into a different cutting subroutine. Several posture control points are set to optimize the cutting posture to prevent motion interference. The notch cutting subroutines are compiled at the lowest point of the part clamping posture. S5: First, the cutting trajectory of each subroutine is preliminarily debugged according to the deviation between the indicator light and the marking line during the simulated cutting, and then each subroutine is debugged as needed according to the measurement results after the first piece is cut.

2. The three-dimensional laser cutting method of a "X"-shaped cross-section frame according to claim 1, characterized in that: The rotary table in S1 is a CNC rotary device. When its rotation plane is parallel to the XZ plane and is in the zero position, the tooling and the rotary table are aligned as a whole by adsorbing the dial indicator on the cutting head or using the collision monitoring function of the cutting head.

3. The three-dimensional laser cutting method of a "X"-shaped cross-section frame according to claim 1, characterized in that: In the S2, the cross section of the symmetry plane of the part is at the lowest point, that is, the heights in the Z direction of both ends are consistent.

4. The three-dimensional laser cutting method of a "X"-shaped cross-section frame according to claim 1, characterized in that: In S3, the collision monitoring function of the cutting head or the dial indicator is used for alignment and centering, so that the rotary plane of the tooling is parallel to the XZ plane of the machine tool, and the symmetry center point of the tooling is calculated and determined, and the position of the part in the machine tool is determined after conversion.

5. The three-dimensional laser cutting method of a "X"-shaped cross-section frame according to claim 1, characterized in that: The S4 adopts the relative coordinate programming method to convert the notch distribution angle into the rotation angle of each pair of notches about the symmetry plane when the arc length of the part is symmetrical about the YZ plane. The angle required for each pair of notches to rotate from the clamping zero position state to the lowest point of the part clamping posture and the movement amount in the X and Z directions are calculated. All circular holes are compiled into a subroutine and called in the clamping zero position state. The cutting order of all notches and circular holes is symmetrical cutting from the middle of the part to both ends.

6. The three-dimensional laser cutting method of a "X"-shaped cross-section frame according to claim 5, characterized in that: r0, the outer arc radius R of the part and the angular distribution α of the notch on the part calculated by the structural dimensions of the fixture and the rotary table i Calculate the angle that the tooling should rotate around its own rotation axis after cutting each pair of notches, and the movement of the center of the i-th pair of notches in the X and Z directions Δ xi , Δ zi , after the rotation is completed, the corresponding notch cutting subprogram is called, and the program header and program tail are added to form a three-dimensional laser cutting program; Because R, α i , r0 is known, calculate Δ according to the following formula xi , Δ zi : The α i is the distribution angle of the i-th pair of notches about the symmetry plane of the part, that is, the distribution angle of the notch center about the arc length symmetry plane of the part, r0 is the minimum rotation radius, r i is the rotation radius of the center of the i-th pair of notches, β i is the center distribution angle of the tooling circle of the i-th pair of notches in the clamping zero position state, l i is the moving distance of the i-th pair of notch centers in the XZ plane, Δ xi , Δ zi They are the movement of the centers of the i-th pair of notches in the X and Z directions, that is, the change of the corresponding coordinate axes in the program when the subroutine is called.

7. The three-dimensional laser cutting method of a "X"-shaped cross-section frame according to claim 1, characterized in that: In S5, the clamping position of the part is slightly adjusted according to the deviation between the indicator light of the first pair of notches and the scribe line in the arc length direction of the part during the simulated cutting, so that the scribe line and the indicator light coincide with each other in the arc length direction.

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