High-precision laser cutting tool and cutting method for variable-cross-section semi-cylindrical sheet metal part

Abstract

The invention discloses a high-precision laser cutting tool and cutting method for a variable-cross-section semi-cylindrical sheet metal part, relates to the technical field of laser cutting, and solves the problem of cutting precision deviation of such parts. The tool designed by the invention comprises the reference plane used for drawing the arc length contour line of the part in the early stage and detecting the arc length size of the part, the whole tool is formed by splicing and welding a plurality of common steel plates, and the upper molded surface of each vertical plate is consistent with the outer surface of the part in shape, so that the effective fitting and supporting effects on the part are ensured; and the other steel plates have fixing and reinforcing effects. The cutting method comprises the steps that allowance is reserved for lineation on a sheet metal part, cutting is conducted after red light emitted by the laser device is manually adjusted and aligned with the lineation, after cutting is completed, the deviation between the actual cutting size and the expected cutting size is calculated through measurement, and then correction is conducted by adjusting the ordinate value in the cutting program. And finally, precise cutting of the variable-cross-section semi-cylindrical sheet metal part is achieved, and the high-precision size requirement of the part is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser cutting, in particular to a high-precision laser cutting tool and method for variable cross-section semi-cylindrical sheet metal parts. BACKGROUND

[0002] With the rapid development of the aerospace field, the requirements for flight equipment are gradually increasing, and therefore the size requirements for each component of the flight equipment are becoming increasingly stringent. In variable cross-section semi-cylindrical parts, the diameter of some parts reaches φ500mm, and the semi-circular arc length reaches 800mm, but the overall arc length tolerance is only 0 to +0.2mm, and the single-sided tolerance is only 0 to +0.1mm, so the size tolerance requirement is extremely strict, approaching the requirements of numerical control milling. Due to the existence of certain deviations in the shape and structure of the sheet metal parts, the thickness deviation of the parts, and the deviation of the laser cutting precision, the traditional laser cutting method cannot directly complete the profile forming of the parts in one step, and often requires manual tooling and precise grinding to complete the accurate profile forming of the parts, which has many disadvantages such as long overall process flow, long time consumption, and high labor proportion. In addition, the consistency of the parts is poor, and there is a certain proportion of unqualified products.

[0003] Furthermore, the variable cross-section semi-cylindrical parts may have a certain degree of springback or deformation during the forming process. If a convex die tool structure is used, the sheet metal part will wrap the entire tool inside it. In this way, it is not possible to directly observe and detect whether the part is clamped against the tire, and it can only be indirectly inspected by knocking and identifying the sound, which has a large error. SUMMARY

[0004] The present application is to solve the problem of cutting precision deviation of variable cross-section semi-cylindrical parts mentioned above, and therefore proposes a high-precision laser cutting tool and method for variable cross-section semi-cylindrical sheet metal parts. The present application supports the variable cross-section semi-cylindrical parts through a concave die tool, makes a reserved allowance marking on the sheet metal part, and adjusts the cutting path coordinate value according to the actual cutting size, to realize the accurate cutting of the variable cross-section semi-cylindrical sheet metal part, and meet the high-precision size requirement of the part.

[0005] The present application proposes a high-precision laser cutting tool for variable cross-section semi-cylindrical sheet metal parts, which is composed of multiple steel plates welded together, and the overall tool has a concave die structure. After the sheet metal part is clamped on the concave die structure, the gap between the vertical plates is used to check the degree of clamping against the tire before cutting the sheet metal part by inserting a feeler gauge.

[0006] Furthermore, two reference planes are provided on the upper surface of the tool, and the height difference between the reference planes and the theoretical cutting position of the sheet metal part is a fixed size. The reference planes can be used to deduce the theoretical cutting position of the sheet metal part. The reference planes are also used to check the accuracy of the cutting size of the sheet metal part.

[0007] Further, the upper surface of the tool contacts the part position and is provided with a chamfer structure, which ensures effective support for the sheet metal part without interfering with the laser head cutting.

[0008] Further, the chamfer structure and the concave die surface are smoothly transitioned.

[0009] A cutting method using the above-mentioned variable cross-section semi-tubular sheet metal part high-precision laser cutting tool, comprising the following steps: Step one, place the sheet metal part in the tool, and use the magnetic attraction method to fix the part blank and the tool, and use the plug gauge to detect the fit degree of the sheet metal part after molding; Step two, use the height gauge to draw a line on the inspection reference plane, and the reserved amount is N+2X mm, N is the theoretical size, and 2X is the reserved amount; use the red light emitted by the laser cutting equipment to manually adjust and align with the line, and fit the cutting path through the front, middle and rear three points and the alignment positioning method; Step three, ① according to the line, carry out the first reserved amount cutting, and use the height gauge to measure the actual cutting size, calculate the deviation between the actual cutting size and the expected cutting size, and then adjust the longitudinal coordinate value of the three points for correction; ② after correction, carry out the second cutting, reduce the longitudinal coordinate value of the three points by X mm, still carry out the cutting in the reserved amount mode, and again use the height gauge to measure the actual cutting size, detect whether there is a deviation between the actual cutting size and the expected reserved amount size N+X mm, and detect whether the cutting size is accurate; ③ after verifying the accuracy of the second cutting, adjust the longitudinal coordinate value to N mm for the third cutting, that is, the actual cutting size of the part; Step four, after the first cutting is accurate, the subsequent batch production can be cut according to the last accurate cutting mode.

[0010] The variable cross-section semi-tubular sheet metal part high-precision laser cutting tool and the cutting method have the following beneficial effects: (1) The variable cross-section semi-tubular sheet metal part high-precision laser cutting tool and the cutting method can support the sheet metal part through the concave die tool, and can fix the sheet metal part through the high-strength magnet, and can detect the fit degree between the sheet metal blank and the tool through the gap between the various vertical plates of the tool, through the plug gauge and visual inspection.

[0011] (2) The high-precision laser cutting tool and cutting method for the variable cross-section semi-cylindrical sheet metal part, the height gauge is used to draw a reserved allowance line on the inspection reference plane of the tool, the laser head of the laser cutting equipment is used to calibrate the reserved allowance line, the cutting path is fitted through the alignment of three coordinate points, after the first cutting, the coordinate values of the subsequent cutting path are adjusted according to the actual cutting size, the accurate cutting of the variable cross-section semi-cylindrical sheet metal part is realized, the high-precision size requirement of the part is met, and the cutting accuracy can be detected in the early stage of the cutting process. BRIEF DESCRIPTION OF DRAWINGS

[0012] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this application, illustrate embodiments of the application and explain them, which do not constitute an inappropriate limitation on the application.

[0013] In the drawings: Figure 1 is a schematic view of the variable cross-section semi-cylindrical sheet metal part according to the present application; Figure 2 is a schematic view of the punch tooling according to the background art; Figure 3 is a schematic view of the high-precision laser cutting tool for the variable cross-section semi-cylindrical sheet metal part according to the present application; Figure 4 is a schematic view of the plug gauge inspection position of the high-precision laser cutting tool for the variable cross-section semi-cylindrical sheet metal part according to the present application; Figure 5 is a schematic view of the inspection reference plane of the high-precision laser cutting tool for the variable cross-section semi-cylindrical sheet metal part according to the present application; Figure 6 is a schematic view of the reserved allowance line on the variable cross-section semi-cylindrical sheet metal part according to the present application; Figure 7 is a schematic view of the calibration position on the variable cross-section semi-cylindrical sheet metal part according to the present application; Wherein: 1-end plate, 2-stand plate, 3-top plate, 4-bottom plate, 5-connection plate, 6-inspection reference plane, 7-first cutting position, 8-second cutting position, 9-third cutting position, 10-calibration starting point, 11-calibration intermediate point, 12-calibration end point, 13-plug gauge inspection position one, 14-plug gauge inspection position two. DETAILED DESCRIPTION

[0014] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0015] Specific implementation method one: see Figures 1-7 The high-precision laser cutting tool for the variable cross-section semi-cylindrical sheet metal part in the embodiment is composed of a plurality of steel plates which are welded together, and the overall tool has a concave die structure. After the sheet metal part is clamped on the concave die structure, the operator uses the gap between the vertical plates 2 to check the tire fit degree of the sheet metal part before cutting by inserting a feeler gauge. The tool includes a base and a plurality of vertical plates 2, and the vertical plates 2 are vertically arranged on the base. End plates 1 are arranged at both ends of the base, and the end plates 1 and the vertical plates 2 are connected by connecting plates 5. The base includes a plurality of bottom plates 4. A top plate 3 is arranged above the vertical plates 2 and the end plates 1, and the upper surface of the top plate 3 is a test reference plane 6. The test reference plane 6 is used to place a height gauge, and is used to pre-leave a margin line on the part contour before cutting, and to test the size of the cut part. A plurality of high-strength magnets are arranged on the vertical plates 2, and the high-strength magnets are used to adsorb and fix the sheet metal part.

[0016] Two reference planes 6 are arranged on the upper surface of the tool on both sides, and the height difference (which can be converted into an arc length) between the reference planes 6 and the theoretical cutting position of the sheet metal part is a fixed size. The reference planes 6 can be used to deduce the theoretical cutting position of the sheet metal part. The reference planes 6 are also used to test the accuracy of the cutting size of the sheet metal part.

[0017] A chamfer structure is arranged at the position where the upper surface of the tool contacts the part, and the chamfer structure supports the sheet metal part without interfering with the cutting of the laser head, thereby supporting the sheet metal part to the greatest extent to ensure the accuracy of the cutting of the part. The chamfer structure and the concave die surface are smoothly transitioned.

[0018] The chamfer structure and the concave die surface are smoothly transitioned.

[0019] A cutting method using the above-mentioned high-precision laser cutting tool for the variable cross-section semi-cylindrical sheet metal part, including the following steps: Step one, place the sheet metal part in the tool, and use the high-strength magnet adsorption method to fix the part blank and the tool, and use the feeler gauge to detect the tire fit degree of the sheet metal part after clamping; Step two, use the height gauge to draw the pre-allowance line on the inspection datum plane 6, the pre-allowance is N+2X mm, N is the theoretical value size, 2X is the allowance left; use the red light emitted by the laser cutting equipment to adjust and align with the line, and fit the cutting path through the alignment and positioning of the front, middle and rear three points. Step three, ① according to the line, carry out the first pre-allowance cutting, and use the height gauge to measure the actual cutting size, calculate the deviation between the actual cutting size and the expected cutting size (N+2X mm), and then correct by adjusting the vertical coordinate value of the three points; ② after correction, carry out the second cutting, reduce the vertical coordinate value of the three points by X mm, still carry out the cutting according to the pre-allowance (N+X mm), and again use the height gauge to measure the actual cutting size, detect whether there is deviation between the actual cutting size and the expected pre-allowance size N+X mm, and detect whether the cutting size is accurate; ③ after verifying the accuracy of the second cutting, adjust the vertical coordinate value to cutting N mm, and carry out the third cutting, that is, the actual cutting size of the part.

[0020] Step four, after the first cutting is accurate, the subsequent batch production can be cut according to the last accurate cutting method.

[0021] The specific cutting process of the high-precision laser cutting tool for the variable cross-section half-cylinder sheet metal part in this embodiment is as follows: Place the sheet metal part in the tool and use a high-strength magnet to fix it; use a plug gauge to detect the tire tightness of the sheet metal part after molding at plug gauge inspection position one 13 and plug gauge inspection position two 14.

[0022] Place the height gauge on the inspection datum plane 6 on the tool to draw the pre-allowance line, the height gauge line drawing form is as shown in Figure 6 , first draw the line 10 mm higher than the actual cutting position line of the sheet metal part, as indicated by the pre-allowance line 7 in Figure 6 , then use the laser head to calibrate the point to fit the cutting path, the calibration point method is as shown in Figure 7 , the number of calibration points is 3, which are calibration starting point 10, calibration intermediate point 11 and calibration ending point 12, as indicated by the positions of the three arrows in Figure 7 , then generate a line on the same plane through the automatic fitting function of the laser cutting equipment.

[0023] The height gauge markings (with a 10mm allowance) are laser-calibrated using the method described above. The first cut is then made with the allowance at position 7. The actual cut dimensions are then checked using a height gauge. If the actual cut dimensions at the three calibration points are 10.08mm, 9.82mm, and 10.26mm higher than the theoretical dimensions, respectively, adjustments can be made by adjusting the vertical coordinate value. Figure 6 As shown, then cut at position 8 (5mm higher than the theoretical value), lowering the longitudinal coordinate of the laser cutting equipment by 10.08-5.0=5.08mm, 9.82-5.0=4.82mm, and 10.26-5.0=5.26mm respectively, leaving a 5.0mm allowance. Check again with a height gauge. Generally, the 5mm allowance has been achieved at this point. After confirming it's acceptable, no further adjustments are needed; simply lower the longitudinal coordinate value by another 5mm to the final size to complete the cut. Figure 6 The final cutting can be performed by following the cutting path at the third cutting position 9 in the program. After the first part is cut, no further adjustments are needed. The adjusted program can be used to directly cut subsequent parts, thus achieving the goal of high-precision laser cutting of variable cross-section semi-cylindrical sheet metal parts.

[0024] In summary, the high-precision laser cutting fixture and method for variable cross-section semi-cylindrical sheet metal parts described in this invention supports the sheet metal part using a concave mold fixture and fixes it with a high-strength magnet. The fit between the sheet metal blank and the fixture can be checked by inserting a feeler gauge and visual inspection through the gaps between the various vertical plates 2 on the fixture. The high-precision laser cutting fixture and method for variable cross-section semi-cylindrical sheet metal parts described in this invention uses a height gauge to mark a pre-reserved allowance on the inspection reference plane of the fixture. The laser head of the laser cutting equipment is used to calibrate the pre-reserved allowance markings. The cutting path is fitted by aligning three coordinate points. After the first cut, the coordinate values ​​of subsequent cutting paths are adjusted according to the actual cutting dimensions to achieve precise cutting of variable cross-section semi-cylindrical sheet metal parts, meeting the high-precision dimensional requirements of the parts. Furthermore, the cutting accuracy can be detected early in the cutting process.

[0025] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the invention. They can also be reasonable combinations of the features described in the above embodiments. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-precision laser cutting fixture for a variable cross-section semi-cylindrical sheet metal part, characterized in that: The tooling is composed of multiple steel plates welded together, and the overall tooling is a concave mold structure. After the sheet metal parts are mounted on the concave mold structure, the fit of the sheet metal parts before cutting is checked by inserting a feeler gauge through the gap between the vertical plates (2).

2. The high-precision laser cutting fixture for variable cross-section semi-cylindrical sheet metal parts according to claim 1, characterized in that: Two reference planes (6) are provided on both sides of the upper surface of the tooling. The height difference between the reference plane (6) and the theoretical cutting position of the sheet metal part is a fixed dimension. The theoretical cutting position of the sheet metal part can be deduced through the reference plane (6). The reference plane (6) is also used to check the accuracy of the cutting dimension of the sheet metal part.

3. The high-precision laser cutting fixture for variable cross-section semi-cylindrical sheet metal parts according to claim 1, characterized in that: The upper surface of the tooling has a chamfered structure at the contact position with the part, which ensures that it provides effective support for the sheet metal part without interfering with the laser head cutting.

4. The high-precision laser cutting fixture for variable cross-section semi-cylindrical sheet metal parts according to claim 3, characterized in that: The chamfered structure and the concave model surface transition smoothly.

5. A cutting method using the high-precision laser cutting fixture for variable cross-section semi-cylindrical sheet metal parts as described in claim 1, characterized in that: Includes the following steps: Step 1: Place the sheet metal part in the fixture, use a magnet to fix the part blank to the fixture, and use a feeler gauge to check the fit of the sheet metal part to the fixture after it is assembled. Step 2: Use a height gauge to mark the sheet metal part on the inspection reference plane (6) with a reserved allowance of N+2Xmm, where N is the theoretical size and 2X is the allowance left; use the red light emitted by the laser cutting equipment to manually adjust and align with the marking, and fit the cutting path by aligning and positioning the front, middle and back three points with the marking. Step 3: ① Make the first cut according to the marked line, leaving a margin, and measure the actual cut size with a height gauge. Calculate the deviation between the actual cut size and the expected cut size, and then correct it by adjusting the ordinate values ​​of the three points; ② After correction, make the second cut, lowering the ordinate values ​​of the three points by X mm, still making the cut with the margin, and measure the actual cut size again with a height gauge to check if there is a deviation between the actual cut size and the expected margin size N+X mm, and check if the cut size is accurate; ③ After verifying the accuracy of the second cut, adjust the ordinate value to the cut size N mm, and make the third cut, which is the cut size of the part in its actual state; Step 4: After the first piece is cut accurately, subsequent batch production can be carried out by cutting in the same way as the last accurate cut.

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