A processing method for bending a plate-like easily deformable workpiece

Abstract

The present application belongs to the field of tooling part processing, and is a processing method for bending plate type easily deformable tooling. Small diameter cutters are selected to reduce cutting force, and the cutting depth of each layer is reduced to reduce the cutting amount. With the reduction of cutting force and cutting amount, the cutting heat and vibration generated during processing are also reduced, thereby reducing the deformation generated during processing. No frame and reinforcing rib are needed during numerical milling, programming is simple, and time consumption is less. No reinforcing rib is pulled during processing, internal stress is released more fully, and after numerical milling, the reinforcing rib does not need to be cut off, so that the situation of deformation after processing does not occur again, and the state of the tooling part is more stable. In the present application, the amount is removed multiple times during processing to release the residual stress in the tooling part, heat treatment, aging, leveling, and grinding processes are reasonably arranged during the intermediate process to modify, and the deformation generated during the processing of the tooling part is gradually removed, so that the deformation generated during processing is gradually reduced, and a balanced and stable state is achieved.

Description

Technical Field

[0001] This invention belongs to the field of tooling parts processing, and is a processing method for easily deformable tooling such as bent plates. Background Technology

[0002] Currently, the main processing method for "easily deformable bending plate fixtures" involves adding reinforcing ribs during the roughing, semi-finishing, and finishing stages to increase the bending resistance of the fixture parts and reduce processing deformation. However, this method requires square plates much larger than the fixture's external dimensions, resulting in low material utilization. Furthermore, the reinforcing ribs need to be positioned carefully during programming, increasing complexity. To ensure more thorough stress release within the fixture parts, the reinforcing ribs need to be thinned in the final roughing and semi-finishing stages, followed by natural aging for at least 72 hours to obtain relatively stable fixture parts. Although most of the internal stress is released during the roughing and semi-finishing stages, the reinforcing ribs still need to be completely removed in the final finishing stage, causing the fixture to deform again with uncontrollable deformation. This method often fails to meet the requirements for high-precision fixture parts. Moreover, this processing method demands a high level of technical skill from the operators, as the number, size, and position of the reinforcing ribs have a decisive impact on the final processing result.

[0003] Adding reinforcing ribs during processing results in more material used for the blank, more complex processing programming, and tooling deformation after the reinforcing ribs are removed, leading to lower controllability of the processing results. Summary of the Invention

[0004] Technical solution

[0005] A processing method for easily deformable tooling such as bent plates, the specific steps of which are as follows:

[0006] 1) Cut the material according to the shape, leaving a machining allowance X in the height direction, and follow the maximum shape on all four sides, leaving a machining allowance Y on each side; allowance X is adjusted according to the dimensional accuracy in the height direction; allowance Y is adjusted according to the length-to-width ratio and shape.

[0007] 2) The upper and lower planes are parallel in the precision planing, and a surface grinding allowance Z is left in the thickness direction; the allowance Z ensures that there is machining allowance in the two subsequent surface grinding processes to meet the final height dimension requirements;

[0008] 3) The fitter manually levels the surface to improve the deformation;

[0009] 4) Rough milling on a CNC milling machine, the specific programming method is as follows:

[0010] The programming method is Powermill programming software, using the contour machining programming method, with a tolerance of 0.1mm, allowance 'a', minimum downcutting step 'b', and selected tool. The maximum outer contour is rough milled out. Allowance 'a' is adjusted according to the length-to-width ratio and shape to ensure that the surrounding surfaces and fillets can be machined during semi-finish milling. Minimum downcutting step 'b' is adjusted according to the tool diameter.

[0011] 5) Simmering and heat leveling improve and eliminate residual internal stress, stabilize dimensions, and reduce deformation;

[0012] 6) The upper and lower planes are parallel during surface grinding. Rough grinding is required first, followed by fine grinding. The two sides are repeatedly turned over and ground to remove the deformation of the upper and lower planes and control the deformation Q of the upper and lower planes. The deformation Q is adjusted according to the allowance of the profile during semi-finish milling to ensure that there is a uniform machining allowance when the semi-finish milling is aligned.

[0013] 7) Semi-finish milling on a CNC milling machine, the specific programming method is as follows:

[0014] The programming method is Powermill programming software, using the contour machining programming method, with a tolerance of 0.1mm, allowance c, minimum cutting step d, and selected tool. The four sides and fillets are semi-finish milled, and the reference holes are reserved. The allowance c is adjusted according to the length-to-width ratio and shape to ensure that the four sides and fillets can be machined during finish milling. The minimum cutting step d is adjusted according to the tool diameter.

[0015] 8) Under natural conditions, aging for 24 hours improves and eliminates residual stress, and stabilizes the material's microstructure and dimensions;

[0016] 9) The upper and lower planes are parallel during surface grinding. Rough grinding is required first, followed by fine grinding. The two sides are repeatedly turned over for grinding to remove the deformation of the upper and lower planes. The deformation W of the upper and lower planes is controlled. The deformation W is adjusted according to the final surface accuracy to ensure that the surface and fillets can be milled precisely.

[0017] 10) CNC milling for finish milling, the specific programming method is as follows:

[0018] The Powermill programming software is used for programming, employing a contour machining programming method with a tolerance of 0.05mm, allowance e, and minimum downcut step f. This method semi-finish mills the four sides and fillets. The allowance e is adjusted according to the aspect ratio and shape to ensure that the four sides and fillets can be machined during finish milling. The minimum downcut step f is adjusted according to the tool diameter. Under natural conditions, the deformation of the upper and lower planes of the fixture is checked. Once the fixture is stable, contour machining programming is performed with a tolerance of 0.02mm, allowance 0mm, and downcut step for finish milling the four sides and fillets. The minimum-maximum downcut step gh is adjusted according to the tool diameter.

[0019] Furthermore, step 11 is included, where the fitter performs fine polishing of all surfaces and rounded corners, and rounds the sharp corners of non-working parts.

[0020] Furthermore, in step 1, the allowance X is specifically 8mm-12mm, which is adjusted according to the dimensional accuracy in the height direction, and preferably 10mm; in step 1, the allowance Y is specifically 8mm-20mm, which is adjusted according to the aspect ratio and shape, and preferably 13mm-15mm.

[0021] Furthermore, in step 2, the allowance Z is specifically 1mm-3mm, which is adjusted according to the dimensional accuracy in the height direction, and preferably 2mm;

[0022] Furthermore, in step 4, the blade diameter is preferably ≤20mm; in step 4, the allowance a is specifically 3.5mm-6mm, adjusted according to the aspect ratio and shape, preferably 5mm; in step 4, the minimum downward cutting step distance b is specifically ≤0.5mm, adjusted according to the blade diameter.

[0023] Furthermore, in step 6, Q is specifically <0.7mm, and is preferably 0.3mm smaller than the semi-finish milling allowance, depending on the adjustment of the profile allowance during semi-finish milling.

[0024] Furthermore, in step 7, the blade is preferably ≤12mm in diameter;

[0025] Furthermore, in step 7, the allowance c is specifically 0.8mm-1.2mm, which is adjusted according to the aspect ratio and shape, and preferably 1mm; in step 7, the minimum cutting step distance d is specifically ≤0.3mm, which is adjusted according to the tool diameter;

[0026] Furthermore, in step 9, W is specifically ≤0.5mm, which needs to be adjusted according to the final surface accuracy;

[0027] Furthermore, in step 10, the blade diameter is preferably ≤12mm; the allowance e in step 10 is specifically 0.2mm-0.5mm, adjusted according to the aspect ratio and shape, preferably 0.4mm; the minimum downward cutting step distance f in step 10 is specifically ≤0.3mm, adjusted according to the blade diameter;

[0028] In step 10, under natural conditions, the deformation of the upper and lower planes is detected. If the deformation is greater than W, it is necessary to return to step 9 and perform surface grinding again.

[0029] Technical effect

[0030] This invention utilizes the conformal cutting method of tooling parts to save materials and reduce costs. During CNC milling programming, small-diameter tools are selected to reduce cutting forces and depth of cut per layer, thus reducing the amount of material removed. As the cutting force and amount of material removed decrease, the cutting heat and vibration generated during machining also decrease, thereby reducing deformation. CNC milling eliminates the need for reinforcing ribs, simplifying programming and reducing time consumption. Without reinforcing ribs pulling the part during machining, internal stress is released more fully, and there is no need to remove reinforcing ribs after CNC milling, preventing post-machining deformation and resulting in a more stable tooling part. This invention employs multiple, gradual material removal processes during machining to release residual stress within the tooling part. The intermediate processes also include rationally arranged heat treatment, aging, leveling, and surface grinding to gradually remove deformation generated during machining, reducing deformation from large to small, ultimately achieving a balanced and stable state. This invention can be applied to the field of mechanical parts machining, providing a new approach for controlling machining deformation in the machining of weakly rigid parts. Detailed Implementation

[0031] The present invention will be further described below with reference to embodiments. The following description represents only a portion of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] 1. Cut the material according to the shape, leaving a machining allowance of 10mm in the height direction, and follow the maximum shape on all four sides, leaving a machining allowance of 15mm on each side;

[0034] 2. The upper and lower planes are parallel after precision planing, and a 2mm allowance is left for surface grinding in the thickness direction;

[0035] 3. The fitter manually levels the surface to improve the deformation.

[0036] 4. Rough milling on a CNC milling machine, the specific programming method is as follows:

[0037] The programming was performed using Powermill programming software, with a contour machining programming method, a tolerance of 0.1mm, a allowance of 5mm, a minimum downcutting step of 0.5mm, and a φ20r1 flat-bottomed rounded corner tool to rough mill the maximum outer contour.

[0038] 5. Simmering and heat leveling improve and eliminate residual internal stress, stabilize dimensions, and reduce deformation;

[0039] 6. The upper and lower surfaces of the surface should be parallel. Rough grinding is required first, followed by fine grinding. The surfaces should be turned over repeatedly to remove the deformation of the upper and lower surfaces. The deformation should be controlled to be <0.7mm.

[0040] 7. Semi-finish milling on a CNC milling machine, the specific programming method is as follows:

[0041] The programming is done using Powermill programming software, with a contour machining programming method, a tolerance of 0.1mm, a allowance of 1mm, a minimum cutting step of 0.3mm, and a φ12r1 flat-bottomed rounded corner cutter. The four sides and rounded corners are semi-finished and milled, and a reference hole is reserved.

[0042] 8. Under natural conditions, after aging for 24 hours, residual stress is improved and eliminated, and the material microstructure and dimensions are stabilized;

[0043] 9. The upper and lower surfaces of the surface should be parallel. Rough grinding is required first, followed by fine grinding. The surfaces should be turned over repeatedly to remove the deformation of the upper and lower surfaces. The deformation should be controlled to be ≤0.5mm.

[0044] 10. CNC milling for finish milling; the specific programming method is as follows:

[0045] The Powermill programming software is used for programming, employing a contour machining programming method with a tolerance of 0.05mm, a allowance of 0.4mm, and a minimum cutting step of 0.3mm. The four sides and fillets are semi-finish milled. The deformation of the fixture is checked under natural conditions. Once the fixture is stable, contour machining programming is performed again with a tolerance of 0.02mm, a allowance of 0mm, and (minimum, maximum) cutting step of (0.2, 0.3)mm. The four sides and fillets are then finish milled.

[0046] 11. The fitter performs fine finishing and polishing of all surfaces and rounded corners, and rounds the sharp corners of non-working parts.

[0047] Results: The processing method of this invention produces qualified parts.

[0048] Example 2

[0049] The processing method for easily deformable tooling such as bent plates, with the following specific steps:

[0050] 1. Cut the material according to its shape, leaving a machining allowance X in the height direction, and follow the maximum shape on all four sides, leaving a machining allowance Y on each side; allowance X is adjusted according to the dimensional accuracy in the height direction; allowance Y is adjusted according to the length-to-width ratio and shape.

[0051] 2. The upper and lower planes are parallel after precision planing, and a surface grinding allowance Z is left in the thickness direction; the allowance Z ensures that there is machining allowance for the two subsequent surface grinding operations to meet the final height dimension requirements;

[0052] 3. The fitter manually levels the surface to improve the deformation.

[0053] 4. Rough milling on a CNC milling machine, the specific programming method is as follows:

[0054] The programming method is Powermill programming software, using the contour machining programming method, with a tolerance of 0.1mm, allowance 'a', minimum downcutting step 'b', and selected tool. The maximum outer contour is rough milled out. Allowance 'a' is adjusted according to the length-to-width ratio and shape to ensure that the surrounding surfaces and fillets can be machined during semi-finish milling. Minimum downcutting step 'b' is adjusted according to the tool diameter.

[0055] 5. Simmering and heat leveling improve and eliminate residual internal stress, stabilize dimensions, and reduce deformation;

[0056] 6. The upper and lower surfaces should be parallel during surface grinding. Rough grinding is required first, followed by fine grinding. The surfaces should be repeatedly turned over and ground to remove the deformation of the upper and lower surfaces and control the deformation Q of the upper and lower surfaces. The deformation Q should be adjusted according to the allowance of the profile during semi-finish milling to ensure that there is a uniform machining allowance during semi-finish milling alignment.

[0057] 7. Semi-finish milling on a CNC milling machine, the specific programming method is as follows:

[0058] The programming method is Powermill programming software, using the contour machining programming method, with a tolerance of 0.1mm, allowance c, minimum cutting step d, and selected tool. The four sides and fillets are semi-finish milled, and the reference holes are reserved. The allowance c is adjusted according to the length-to-width ratio and shape to ensure that the four sides and fillets can be machined during finish milling. The minimum cutting step d is adjusted according to the tool diameter.

[0059] 8. Under natural conditions, after aging for 24 hours, residual stress is improved and eliminated, and the material microstructure and dimensions are stabilized;

[0060] 9. The upper and lower planes are parallel during surface grinding. Rough grinding is required first, followed by fine grinding. The two sides are repeatedly turned over for grinding to remove the deformation of the upper and lower planes. The deformation W of the upper and lower planes is controlled. The deformation W is adjusted according to the final surface accuracy to ensure that the surface and fillets can be milled precisely.

[0061] 10. CNC milling for finish milling; the specific programming method is as follows:

[0062] The Powermill programming software is used for programming, employing a contour machining programming method with a tolerance of 0.05mm, allowance e, and minimum downcut step distance f. This is used for semi-finish milling of the four sides and fillets. The allowance e is adjusted according to the aspect ratio and shape to ensure that the four sides and fillets can be machined during finish milling. The minimum downcut step distance f is adjusted according to the tool diameter. Under natural conditions, the deformation of the upper and lower planes of the fixture is checked. Once the fixture is stable, contour machining programming is performed with a tolerance of 0.02mm, allowance 0mm, and a (minimum-maximum) downcut step distance (gh) for finish milling of the four sides and fillets. The minimum-maximum downcut step distance (gh) is adjusted according to the tool diameter.

[0063] Furthermore, step 11 is included, where the fitter performs fine polishing of all surfaces and rounded corners, and rounds the sharp corners of non-working parts.

[0064] Furthermore, the conformal cutting in step 1 saves materials and reduces costs compared to existing cutting methods;

[0065] Furthermore, in step 1, the allowance X is specifically 8mm-12mm, which is adjusted according to the dimensional accuracy in the height direction, and preferably 10mm;

[0066] Furthermore, in step 1, the allowance Y is specifically 8mm-20mm, which can be adjusted according to the aspect ratio and shape, and is preferably 13mm-15mm;

[0067] Furthermore, in step 2, the allowance Z is specifically 1mm-3mm, which is adjusted according to the dimensional accuracy in the height direction, and preferably 2mm;

[0068] Furthermore, in step 4, the blade is preferably ≤20mm in diameter;

[0069] Furthermore, in step 4, the allowance 'a' is specifically 3.5mm-6mm, which can be adjusted according to the aspect ratio and shape, with 5mm being preferred.

[0070] Furthermore, in step 4, the minimum cutting step distance b is specifically ≤0.5mm, which is adjusted according to the tool diameter;

[0071] Furthermore, in step 6, Q is specifically <0.7mm, and is preferably 0.3mm smaller than the semi-finish milling allowance, depending on the adjustment of the profile allowance during semi-finish milling.

[0072] Furthermore, in step 7, the blade is preferably ≤12mm in diameter;

[0073] Furthermore, in step 7, the allowance c is specifically 0.8mm-1.2mm, which can be adjusted according to the aspect ratio and shape, and is preferably 1mm;

[0074] Furthermore, in step 7, the minimum downward cutting step distance d is specifically ≤0.3mm, which is adjusted according to the tool diameter;

[0075] Furthermore, in step 9, W is specifically ≤0.5mm, which needs to be adjusted according to the final surface accuracy;

[0076] Furthermore, in step 10, the diameter of the blade is preferably ≤12mm;

[0077] Furthermore, in step 10, the allowance e is specifically 0.2mm-0.5mm, which can be adjusted according to the aspect ratio and shape, and is preferably 0.4mm;

[0078] Furthermore, in step 10, the minimum downward cutting step distance f is specifically ≤0.3mm, which is adjusted according to the tool diameter;

[0079] Furthermore, in step 10, under the natural state, the deformation of the upper and lower planes is detected. If the deformation is greater than W, it is necessary to return to step 9 and perform surface grinding again.

[0080] Furthermore, in step 10, the (minimum-maximum) cutting step distance (gh) is specifically (0.05-0.3) mm, which is adjusted according to the tool diameter.

[0081] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein. The specific embodiments described above further illustrate the purpose, technical solutions, 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 present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A processing method for easily deformable tooling such as bent plates, characterized in that, The specific steps are as follows: Step 1: blanking, leaving a machining allowance X in the height direction, and following the maximum contour around, leaving a machining allowance Y on one side; the allowance X is adjusted according to the dimensional accuracy in the height direction; the allowance Y is adjusted according to the length-width ratio and shape; Step 2: fine planing of the upper and lower planes to be parallel, leaving a planing allowance Z in the thickness direction; the allowance Z ensures that there is a machining allowance for the subsequent two times of planing, and meets the final height size requirement; Step 3: hand leveling by a bench worker to improve the deformation condition; Step 4: rough milling on a numerical control milling machine, and the specific programming method is as follows: The powermill programming software is used for programming, the contour machining programming method is used, the tolerance is 0.1mm, the allowance a is selected, the minimum step-down distance b is selected, the tool is selected, and the maximum contour is rough milled; the allowance a is adjusted according to the length-width ratio and shape to ensure that the semi-finish milling can be machined; the minimum step-down distance b is adjusted according to the tool diameter; Step 5: tempering, hot leveling, improving and eliminating residual internal stress, stabilizing the size, and reducing deformation; Step 6: planing the upper and lower planes to be parallel, requiring rough grinding first, then fine grinding, repeatedly turning over and grinding to remove the deformation amount of the upper and lower planes, and controlling the deformation amount Q of the upper and lower planes; the deformation amount Q is adjusted according to the semi-finish milling surface allowance to ensure that there is a uniform machining allowance when the semi-finish milling is aligned; Step 7: semi-finish milling on a numerical control milling machine, and the specific programming method is as follows: The powermill programming software is used for programming, the contour machining programming method is used, the tolerance is 0.1mm, the allowance c is selected, the minimum step-down distance d is selected, the tool is selected, the semi-finish milling is performed on the four surrounding surfaces and the corners, and the reference hole is reserved; the allowance c is adjusted according to the length-width ratio and shape to ensure that the finish milling can be machined; the minimum step-down distance d is adjusted according to the tool diameter; Step 8: aging for 24 hours in a natural state to improve and eliminate residual stress, stabilize the material structure and size; Step 9: planing the upper and lower planes to be parallel, requiring rough grinding first, then fine grinding, repeatedly turning over and grinding to remove the deformation amount of the upper and lower planes, and controlling the deformation amount W of the upper and lower planes; the deformation amount W is adjusted according to the final surface accuracy to ensure that the surface and the corner can be finish milled; Step 10: finish milling on a numerical control milling machine, and the specific programming method is as follows: The powermill programming software is used for programming, the contour machining programming method is used, the tolerance is 0.05mm, the allowance e is selected, the minimum step-down distance f is selected, and the semi-finish milling is performed on the four surrounding surfaces and the corners; the allowance e is adjusted according to the length-width ratio and shape to ensure that the finish milling can be machined; the minimum step-down distance f is adjusted according to the tool diameter; the deformation amount of the upper and lower planes of the tool is checked in a natural state, the tool state is stable, the contour machining programming is performed again with a tolerance of 0.02mm and an allowance of 0mm, the step-down distance is selected, and the four surrounding surfaces and the corners are finish milled; the minimum-maximum step-down distance g-h is adjusted according to the tool diameter.

2. The method according to claim 1, wherein Step 11 is also included, which is to polish all the surfaces and corners by a bench worker, and the sharp corners of the non-working part are rounded.

3. The method according to claim 1, wherein The allowance X in step 1 is specifically 8mm-12mm, which is adjusted according to the dimensional accuracy in the height direction; the allowance Y in step 1 is specifically 8mm-20mm, which is adjusted according to the length-width ratio and shape.

4. The method of claim 1, wherein the method further comprises: The excess Z in step 2 is specifically 1mm-3mm, which is adjusted according to the dimensional accuracy in the height direction.

5. The method of claim 1, wherein the method further comprises: The cutter diameter in step 4 is ≤20mm; the excess a in step 4 is specifically 3.5mm-6mm, which is adjusted according to the length-width ratio and shape; the minimum step-down distance b in step 4 is specifically ≤0.5mm, which is adjusted according to the cutter diameter.

6. The method of claim 1, wherein the method further comprises: The Q in step 6 is specifically <0.7mm, which is adjusted according to the excess of the semi-finish milling profile.

7. The method of claim 1, wherein the method further comprises: The cutter diameter in step 7 is ≤12mm; the excess c in step 7 is specifically 0.8mm-1.2mm, which is adjusted according to the length-width ratio and shape; the minimum step-down distance d in step 7 is specifically ≤0.3mm, which is adjusted according to the cutter diameter.

8. The method of claim 1, wherein the method further comprises: The W in step 9 is specifically ≤0.5mm, which is adjusted according to the accuracy of the final profile.

9. The method of claim 1, wherein the method further comprises: The cutter diameter in step 10 is ≤12mm; the excess e in step 10 is specifically 0.2mm-0.5mm, which is adjusted according to the length-width ratio and shape; the minimum step-down distance f in step 10 is specifically ≤0.3mm, which is adjusted according to the cutter diameter.

10. The method of claim 1, wherein the method further comprises: In step 10, the deformation of the upper and lower planes in the natural state is detected; if the deformation is >W, it is necessary to return to step 9 for flat grinding.