Technological method for improving part material utilization rate through cutting-free one-step cutting

Abstract

The invention relates to the technical field of dies, in particular to a technological method for improving the part material utilization rate through cutting-free one-step cutting. S1, determining an optimization target, and preparing a blank; and S2, selecting a proper algorithm for the selected hot-formed product to perform automatic layout on the hot-formed product. And S3, a proper first connecting knife edge and a proper second connecting knife edge are selected for a hot forming product. And S4, a plurality of operation schemes can be obtained through S2 and S3, the schemes are evaluated through theoretical verification of the schemes, and the scheme with the best effect is obtained through comparison. And S5, implementing verification is conducted on the specific forming scheme mentioned in the S4. And S6, after the verification is passed, carrying out stability test on the product. And S7, verifying the material utilization rate of the finally produced effective material. Compared with the prior art, the rolling width and the step pitch are reduced, the overall comprehensive cost is greatly reduced, stamping forming and welding procedures are not affected, and the utilization rate of part materials can be increased.

Description

Technical Field

[0001] The invention relates to the technical field of mold processing, in particular to a process method for improving the utilization rate of part materials by using a one-size-fits-all method without cutting. Background Art

[0002] With the rapid development of the mold industry, the mold development cycle is getting shorter and shorter, the competition for hot-formed parts is becoming more and more fierce, and the demand for cost control of hot-formed parts is increasing. How to maintain stability in mass production is more critical, but the existing hot-forming process often leads to excess quality, the means of cutting-free assembly are immature, and the material processing utilization rate is low. Summary of the invention

[0003] In order to overcome the shortcomings of the prior art, the present invention provides a process method for improving the material utilization rate of parts by using a one-size-fits-all method without cutting. According to the simulation of the forming software, the material piece can be cut without cutting. According to the position left by the connecting knife and the modification amount, combined with the mold positioning, the two ends of the material piece can be nested. This layout method is conducive to improving the material utilization rate, and the width step of the blanking layout roll becomes smaller, and the mold size will become smaller and simpler accordingly. The arrangement of the material piece enables the discharge collection and improves the stamping efficiency, which can meet the stability of mass production and reduce costs.

[0004] In order to achieve the above purpose, a process method is designed to improve the material utilization rate of parts by using a one-size-fits-all method without cutting, which specifically includes the following steps: S1: Determine the optimization target and prepare the blank. S2: Select a suitable algorithm for the selected hot-formed product to automatically arrange the hot-formed product. S3: Select suitable cutting edge 1 and cutting edge 2 for the hot-formed product. S4: Multiple operation plans can be obtained from the above S2 and S3. The theoretical verification of the plan is used to evaluate multiple plans, and the best plan is obtained after comparison. S5: Implement and verify the specific forming plan mentioned in S4. S6: After verification, perform stability test on the product. S7: Verify the material utilization rate of the effective material obtained in the final output.

[0005] The blank described in S1 includes but is not limited to the lower inner panel of the H-pillar. The thickness of the processed blank needs to be between 1.0 and 2.1 mm; and the tensile strength meets 550 MPA.

[0006] The automatic nesting steps described in S2 include S21: importing the geometric data of the parts and importing the tool curve; S22: defining the nesting parameters and constraints, defining the drawing model, and unfolding the model; S23: determining the nesting method, selecting the appropriate nesting strategy, and determining the process incision and nesting method according to the maximum shape of the sheet; S24: setting the spacing between two sheets, and setting the overlap distance between the forming boundary and the product edge line; S25: outputting the nesting plan and related data.

[0007] The constraints described in S22 are: the mold size needs to be at least 4500×2500 mm; the gap size between the mold and the sheet is 5%~10% of the thickness of the sheet.

[0008] The process cuts described in S23 are generally continuous cuts on the same material strip; the nesting method can use straight line, diagonal, spiral or other methods suitable for the sheet.

[0009] The cutting edge standard described in S3 is that the cutting edge of the first half of the process step is as wide as possible, and the cutting edge of the latter process step is centered and perpendicular to the cutting edge cut in the previous step. The minimum width of the cutting edge needs to be guaranteed to be 3mm, the minimum radius is 2.5mm, and the transition fillet radius is 5mm.

[0010] The specific process of the theoretical verification described in S4 includes S41: importing the geometric information and material properties of the parts, and importing the layout parameters; S42: generating a layout plan by software calculation and analysis; S43: analyzing and calculating the material thickness, material size, material utilization rate, product weight, tensile strength, yield strength and other parameters of the material sheet obtained after layout; S44: adjusting the layout parameters according to the analysis results, and repeating S42 to S44 until the use requirements are met.

[0011] The specific method of implementing the verification described in S5 is to verify the shape of the blanking model by laser cutting, including S51: setting parameters such as laser power, cutting speed, and gas pressure according to the material type and thickness; S52: calibrating the equipment, using the calibration tool to accurately calibrate the laser cutting head to ensure cutting accuracy; S53: trial cutting the sheet to check whether the cutting effect meets the requirements, and adjusting the parameters described in S51 until the best cutting effect is achieved; S54: formal cutting, after confirming that the trial cutting effect is correct, start formal cutting; S55: quality inspection, inspect the size, surface quality, edge flatness, etc. of the cut sheet; S56: recording and feedback, recording key data and inspection results in the cutting process, analyzing the problems that arise and proposing improvement measures.

[0012] The laser power described in S51 is generally 3000W; when the sheet thickness is 1.0~1.3mm, the cutting speed is 14~15m / min, when it is 1.4~1.8mm, the cutting speed is 14~15m / min, when it is 1.9~2.1, the cutting speed is 8~11m / min; the air pressure of the cutting machine is generally 13bar.

[0013] The inspection standards described in S55 are: 1. The dimensional accuracy deviation from the parts is no more than 0.5mm. 2. The surface of the sheet should be free of obvious scratches, pits, burrs, indentations should be less than 0.1mm, and the edges should be free of defects such as flanging, curling, and cracks.

[0014] The product stability test method described in S6 is for batch production, which verifies the service life of the insert and the knife block through the progressive blanking die and finally confirms whether the formability is affected, and confirms whether the formability is affected by the stability of the mass-produced sheets.

[0015] The progressive blanking die described in S6 adopts the method of dividing the material on both sides for blanking.

[0016] The material utilization rate verification formula described in S7 is: material utilization rate = (net weight of materials contained in unit product / weight of materials consumed per unit product) × 100%; material utilization rate after optimized layout = (net weight of materials contained in unit product after optimization / weight of materials consumed per unit product) × 100%.

[0017] Compared with the prior art, the present invention adopts a one-size-fits-all solution without cutting, and there is no need to consider the strength of the punching knife block. The roll width and pitch are reduced, the overall comprehensive cost is greatly reduced, and it has no effect on the stamping and welding processes, which can improve the material utilization rate of parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The figure shows the simulation results of the layout of the inner panel under the H-pillar.

[0019] Figure 2 This is a schematic diagram of the position of the knife for cutting the lower inner panel of the H-pillar without cutting.

[0020] Figure 3 This is an enlarged view of the cutting edge for the H-pillar lower inner panel, which can be cut without cutting.

[0021] Figure 4 This is a schematic diagram of the H-pillar lower inner panel being cut and connected in a one-cut manner without cutting.

[0022] Figure 5 It is a flow chart of the present invention.

[0023] like Figure 2 As shown, 1 is the first cutting edge, and 2 is the second cutting edge. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] like Figure 5 As shown, a process method for improving the material utilization rate of parts by using a one-size-fits-all method without cutting is characterized in that it specifically includes the following steps: Step 1: Determine the optimization target and prepare the blank. The thickness of the processed blank is generally between 1.0 and 2.1 mm, and the tensile strength must meet 550 MPA. The present invention takes the lower inner panel of the H-pillar as an embodiment, and can also be applied to one-size-fits-all hot-formed products without cutting or without cutting.

[0026] Step 2: Select a suitable algorithm for the selected hot forming product to automatically nest the hot forming product. The specific process of automatic nesting is as follows: Step 21: Import the geometric data of the part and the tool curve; Step 22: Define the nesting parameters and constraints, define the drawing model, and unfold the model. In order to better accommodate the blank, the mold size needs to be at least 4500×2500mm, and the gap between the mold and the sheet needs to meet 5%~10% of the sheet thickness; Step 23: Determine the nesting method, select a suitable nesting strategy, and determine the process incision and nesting method according to the maximum shape of the sheet. In continuous stamping production, multiple parts are designed on a material strip, and parts are separated by continuous incisions to improve material utilization and production efficiency. The incision position and shape must be accurately calculated during design to ensure the dimensional accuracy and quality of the parts. The nesting method can use linear, diagonal, spiral or other methods suitable for processing sheets according to the required material utilization; Step 24: Set the spacing between two sheets and set the overlap distance between the forming boundary and the product edge line; Step 26: Output the nesting plan and related data. Since the present invention belongs to two-dimensional nesting, the nesting requires arranging as many rectangles as possible under the premise of limited material quantity to minimize waste. Generally, the nesting object is the nesting problem of irregular parts. The nesting software used in the present invention is AutoForm. The nesting methods used include heuristic algorithms and linear programming methods. The heuristic algorithm uses the shortest path method or the minimum remaining space method to perform preliminary nesting to reduce material waste; the linear programming method optimizes material utilization and improves nesting efficiency by establishing a mathematical model and using a linear programming method. Through the rectangular parts nesting optimization method, one or several parts are arranged in a single row or in pairs in a rectangle, and the problem is converted into a rectangle for nesting, such as Figure 1 This is the specific sample arrangement result of the inner panel under the H-pillar.

[0027] Step 3: Choose the appropriate cutting edge for the thermoformed product. In order to ensure the smooth implementation of the one-cut-without-cut process, the cutting edge of the first half of the process should be as wide as possible, and the cutting edge of the first step should be centered and perpendicular to the cutting edge of the previous step to avoid sharp angles. Figure 2 Figure 3 As shown, the minimum width at the cutting edge needs to be guaranteed to be 3mm, the minimum radius is 2.5mm, and the transition fillet radius is 5mm, which eliminates the problem of requiring a 6mm tool gap between the original cut-free sample sheets and the need to consider the strength of the punching knife block, thus realizing a truly one-size-fits-all processing method.

[0028] Step 4: Multiple operation plans can be obtained from the above steps 2 and 3. The theoretical verification of the plan is used to evaluate multiple plans, and the best plan is obtained after comparison. Step 4 plays the role of theoretical verification. The purpose is to verify whether the formability of the product is affected after automatic nesting. Re-import it into the analysis software for re-analysis. After the analysis is completed, verify the nesting. The specific process of theoretical verification includes step 41: importing the geometric information and material properties of the parts, importing the nesting parameters; step 42: generating the nesting plan by software calculation and analysis; step 43: the result analysis calculates the material thickness, material size, material utilization rate, product weight, tensile strength, yield strength and other parameters; step 44: adjust the nesting parameters according to the analysis results, and repeat steps 42 to 44 until the use requirements are met. The purpose of theoretical verification is to verify whether the forming is affected after automatic nesting and whether the structural positioning adjustment distance is affected. From step 4, the parameters of the H-pillar lower inner panel can be analyzed: material thickness: 2.0 mm; material size: 569×426×2; tensile strength: 850 MPa; yield strength: 515.7 MPa.

[0029] Step 5: Implement and verify the specific forming scheme mentioned in step 4. The specific method of implementing the verification includes step 51: Set the laser power, cutting speed, gas pressure and other parameters according to the material type and thickness. The laser power needs to be adjusted according to the thickness and type of the material to ensure cutting efficiency and quality. The cutting speed should match the laser power to avoid incomplete cutting due to too fast or unnecessary energy waste due to too slow cutting. The laser power is generally 3000W; when the thickness of the sheet is 1.0~1.3mm, the cutting speed is 14~15m / min, when it is 1.4~1.8mm, the cutting speed is 14~15m / min, when it is 1.9~2.1, the cutting speed is 8~11m / min; the gas pressure of the cutting machine is generally 13bar; step 52: Calibrate the equipment, use the calibration tool to accurately calibrate the laser cutting head to ensure cutting accuracy; step 53: Trial cutting of the sheet, check whether the cutting effect meets the requirements, and adjust the parameters until the best cutting effect is achieved; Step 54: Formal cutting, after confirming that the trial cutting effect is correct, start formal cutting; Step 55: Quality inspection, inspect the size, surface quality, edge flatness and other aspects of the cut sheet. The inspection standards are: 1) The deviation from the dimensional accuracy of the parts is not more than 0.5mm; 2) The sheet surface is required to have no obvious scratches, pits, burrs, and the indentation should be less than 0.1mm. The edge should have no defects such as flanging, curling, and cracks. The surface should be smooth and flat, without oil stains or rust. Step 56: Record and feedback, record the key data and inspection results during the cutting process, analyze the problems that arise and propose improvement measures. In step 5, the laser cutting method is used to verify the shape of the blanking die for simulation verification and analysis, and there is no need to repeatedly open the die to verify the forming condition of the blanking die.

[0030] Step 6: After verification, conduct stability test on the product. The product stability test method described in step 6 is for batch production. The service life of the inserts and blocks is verified through the progressive blanking die, and the formability is finally confirmed whether it is affected. The stability of the mass-produced blanks is confirmed whether the formability is affected. The purpose of the stability test is to verify the service life and whether there are problems with the blade chipping and burr generation. Figure 4 As shown, the progressive blanking die in step 6 adopts the method of dividing the materials on both sides for blanking. The two sheets of materials slide down from the front and right sides of the die respectively. The two sheets of materials are stacked separately, so there is no need for manual sorting, which improves the efficiency of blanking and stamping.

[0031] Step 7: Verify the material utilization rate of the effective materials finally obtained, and use the material utilization rate verification formula: material utilization rate = (net weight of materials contained in unit product / weight of materials consumed per unit product) × 100%; material utilization rate after optimized layout = (net weight of materials contained in unit product after optimization / weight of materials consumed per unit product) × 100%. In the embodiment of the present invention, the material utilization rate of the lower inner plate of the H-pillar is increased from 1.67×2kg / 4.133kg to 1.67×2kg / 3.8kg after layout optimization, and from 80.8% to 87.9%.

[0032] The present invention can simulate automatic arrangement of cutting-free or non-cutting sheets through step 2, theoretically verify the scheme through step 4, implement verification through step 5, and confirm batch stability through step 6, ultimately eliminating the 6mm upper die space between the original cutting-free arrangement sheets. The one-size-fits-all processing mode no longer needs to consider the strength of the upper die, and can achieve the purpose of increasing material utilization. The sheets can also be separated during the blanking process in step 6. Local steps can be optimized and adjusted in all processes, and can be applied to any parts that can be exempted from cutting. The implementation is simple and easy to understand, and the cost can be greatly reduced.

Claims

1. A process method for improving the material utilization rate of parts by using a one-size-fits-all process without cutting, characterized in that: The specific steps include: S1: Determine the optimization target and prepare the blank. S2: Select a suitable algorithm for the selected hot forming product to automatically arrange the hot forming product. S3: Select the appropriate cutting edge 1 (1) and cutting edge 2 (2) for the hot forming product. S4: From the above S2 and S3, multiple operation plans can be obtained, and the plans are theoretically verified. Multiple plans are evaluated and the best plan is obtained through comparison. S5: Implement and verify the specific forming plan mentioned in S4. S6: After verification, the product is tested for stability. S7: Verify the material utilization rate of the effective material obtained in the final output.

2. A process method for improving the utilization rate of part materials by cutting-free one-size-fits-all according to claim 1, characterized in that: The blank described in S1 includes but is not limited to the lower inner panel of the H-pillar. The thickness of the processed blank needs to be between 1.0 and 2.1 mm; and the tensile strength meets 550 MPA.

3. The process method for improving the utilization rate of part materials by cutting-free one-size-fits-all according to claim 1, characterized in that: The automatic nesting steps described in S2 include S21: importing the geometric data of the parts and importing the tool curve; S22: defining the nesting parameters and constraints, defining the drawing model, and unfolding the model; S23: determining the nesting method, selecting the appropriate nesting strategy, and determining the process incision and nesting method according to the maximum shape of the sheet; S24: setting the spacing between two sheets, and setting the overlap distance between the forming boundary and the product edge line; S25: outputting the nesting plan and related data.

4. A process method for improving the utilization rate of part materials by cutting-free one-size-fits-all according to claim 3, characterized in that: The constraints described in S22 are: the mold size needs to be at least 4500×2500 mm; the gap size between the mold and the sheet is 5%~10% of the thickness of the sheet.

5. The process method for improving the utilization rate of part materials by cutting-free one-size-fits-all method according to claim 3 is characterized in that: The process cuts described in S23 are generally continuous cuts on the same material strip; the nesting method can use straight line, diagonal, spiral or other methods suitable for the sheet.

6. The process method for improving the utilization rate of part materials by cutting-free one-size-fits-all according to claim 1, characterized in that: The cutting edge standard described in S3 is that the cutting edge of the first half of the process step is as wide as possible, and the cutting edge of the latter process step is centered and perpendicular to the cutting edge cut in the previous step. The minimum width of the cutting edge needs to be guaranteed to be 3mm, the minimum radius is 2.5mm, and the transition fillet radius is 5mm.

7. The process method for improving the utilization rate of part materials by cutting-free one-size-fits-all method according to claim 1, characterized in that: The specific process of the theoretical verification described in S4 includes S41: importing the geometric information and material properties of the parts, and importing the nesting parameters; S42: generating a nesting plan by software calculation and analysis; S43: Analyze and calculate the material thickness, material size, material utilization rate, product weight, tensile strength, yield strength and other parameters after the material arrangement is obtained; S44: Adjust the arrangement parameters according to the analysis results, and repeat S42 to S44 until the use requirements are met.

8. The process method for improving the utilization rate of part materials by cutting-free one-size-fits-all method according to claim 1, characterized in that: The specific method of implementing the verification described in S5 is to verify the shape of the blanking model by laser cutting, including S51: setting parameters such as laser power, cutting speed, and gas pressure according to the material type and thickness; S52: calibrating the equipment, using the calibration tool to accurately calibrate the laser cutting head to ensure cutting accuracy; S53: trial cutting the sheet to check whether the cutting effect meets the requirements, and adjusting the parameters described in S51 until the best cutting effect is achieved; S54: formal cutting, after confirming that the trial cutting effect is correct, start formal cutting; S55: quality inspection, inspect the size, surface quality, edge flatness, etc. of the cut sheet; S56: recording and feedback, recording key data and inspection results in the cutting process, analyzing the problems that arise and proposing improvement measures.

9. The process method for improving the utilization rate of part materials by cutting-free one-size-fits-all method according to claim 9 is characterized in that: The laser power described in S51 is generally 3000W; when the sheet thickness is 1.0~1.3mm, the cutting speed is 14~15m / min, when it is 1.4~1.8mm, the cutting speed is 14~15m / min, when it is 1.9~2.1, the cutting speed is 8~11m / min; the air pressure of the cutting machine is generally 13bar.

10. A process method for improving the utilization rate of part materials by cutting-free one-size-fits-all according to claim 9, characterized in that: The inspection standards described in S55 are:

1. The dimensional accuracy deviation from the parts is no more than 0.5mm; 2. The surface of the sheet should be free of obvious scratches, pits, burrs, the indentation should be less than 0.1mm, and the edges should be free of defects such as flanging, curling, and cracks.

11. The process method for improving the utilization rate of part materials by cutting-free one-size-fits-all method according to claim 1, characterized in that: The product stability test method described in S6 is for batch production, which verifies the service life of the insert and the knife block through the progressive blanking die and finally confirms whether the formability is affected, and confirms whether the formability is affected by the stability of the mass-produced sheet.

12. The process method for improving the utilization rate of part materials by cutting-free one-size-fits-all method according to claim 7, characterized in that: The progressive blanking die described in S6 adopts the method of dividing the material on both sides for blanking.

13. The process method for improving the utilization rate of part materials by cutting-free one-size-fits-all method according to claim 1, characterized in that: The material utilization rate verification formula described in S7 is: Material utilization rate = (net weight of materials contained in unit product / weight of materials consumed per unit product) × 100%; Material utilization rate after optimized layout = (net weight of materials contained in unit product after optimization / weight of materials consumed per unit product) × 100%.

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