A machining method for high-precision super-long flat thin-wall plate

Abstract

The application discloses a processing method of high-precision super-long flat thin-wall plate, which comprises the following steps: using the equal-height iron pad with the width of no more than 5 times of the plate thickness and the spacing of no more than 2.5 times of the plate thickness as the clamping platform, placing the super-long flat part on the cast clamping platform, and improving the rigidity and the shock resistance of the super-long flat part clamping system; rough and semi-precision processing is conducted on the clamped super-long flat part, small cutting depth, fast feeding and high-speed milling are adopted, the periphery plane allowance is removed symmetrically and uniformly, the plane is turned over after 1-1.5 mm of processing, the symmetrical plane is processed, the plane is turned over again after 1-1.5 mm of processing, and the cycle operation is conducted, the part is lifted by the special lifting and turning-over tool, and the deformation during lifting and turning-over is reduced; and the process arrangement comprises multiple loose and turning-over, clinical shape correction, deformation control and flexible clamping.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of mechanical processing, and particularly relates to a processing method of high-precision super-long flat thin-wall plate. BACKGROUND

[0002] The high-precision super-long flat thin-wall plate is a key part of certain equipment, has a length of 7520, a cross-sectional dimension of 66x50, and belongs to a typical super-thin long thin-wall plate part. In addition, the part is uniformly provided with 35 grooves with a dimension of 56x10, and each of the two side surfaces is provided with a groove with a dimension of 10x28 and a dimension of 17x25. The main plane has a roughness of Ra1.6, a flatness of 0.15, a parallelism between surfaces of 0.15, and a perpendicularity of 0.05. The part has poor rigidity, and is easily deformed in the machining process due to the influence of factors such as cutting force, clamping force, cutting heat, and residual stress, thereby causing the straightness and flatness of the part to be out of tolerance. In addition, resonance occurs between the tool and the part during cutting, and obvious shaking phenomenon occurs, the surface is provided with vibration marks, and the roughness is difficult to meet the requirements. In addition, when the uniformly distributed grooves on the machined plane are machined by using the clamping and pressing clamping and then milling, the part is obviously bent after machining, and the maximum bending amount is about 5mm. SUMMARY

[0003] In order to overcome the shortcomings of the prior art, the present application provides a processing method of high-precision super-long flat thin-wall plate to solve the technical problems of machining deformation and precision out of tolerance.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical scheme: a processing method of high-precision super-long flat thin-wall plate, characterized by comprising the following steps:

[0005] (1) using a cast iron material with a width of not more than 5 times the thickness of the plate and a spacing of not more than 2.5 times the thickness of the plate as an equal-height iron pad as a clamping platform, placing the super-long flat part on the cast clamping platform, and improving the rigidity and shock resistance of the super-long flat part clamping system;

[0006] (2) The clamped ultra-long flat parts are rough and semi-finished. The small depth of cut and fast feed high-speed milling method is used to remove the excess material of the large planes on all four sides symmetrically and evenly. After machining 1 to 1.5 mm of the large plane, it is flipped over and the symmetrical surface is machined. The same process is repeated for 1 to 1.5 mm. The parts are lifted by special lifting and flipping fixtures to reduce the deformation during lifting and flipping. According to the cutting performance of the thin-walled plate material, the cutting tools and cutting parameters are selected to control the deformation of rough and semi-finishing to be less than 0.5 mm. The grooves on both sides of the parts, the positioning pin holes and keyways are rough milled and allowances are left during the semi-finishing of the large planes on all four sides. After the semi-finishing is completed, the screw holes are machined to the required position to reduce the impact of drilling on the plane accuracy. After the large planes on all four sides are machined to the required size, the grooves on both sides are finished to control the deformation of the finishing to be less than 0.2 mm.

[0007] The machining plane adopts a multi-point evenly distributed side top clamping method to reduce the clamping force during plane milling. The machining of side grooves adopts side positioning. The machining of large planes, stepped surfaces, and side grooves adopts a multi-point evenly distributed pressure plate clamping method.

[0008] After each plane is machined, the parts are manually vibrated and shaped using square timber to equalize the residual milling stress.

[0009] For the parts after being lifted and flipped, the grooved surfaces are machined at intervals. Each stepped surface is removed evenly in stages using a single cut, with each cut depth not exceeding 0.3mm. Odd-numbered grooves are machined sequentially. After all odd-numbered grooves are machined, even-numbered grooves are machined sequentially in the same way.

[0010] In the above technical solution, in step (2), the distance between the lower end of the wooden block and the upper plane of the part during the shaping process is no more than 300mm, and the number of taps is no less than 5 times each time.

[0011] In the above technical solution, in step (2), the part is flipped using a flipping tool. The flipping tool is designed with an opening size 2mm larger than the part blank thickness and a depth no greater than the part width, and is a 4 / 5 U-shaped open clamp.

[0012] In the above technical solution, in step (2), during rough machining, a three-sided groove milling cutter with a small cutting depth and multiple milling operations are used to remove the excess material of the grooves on both sides, leaving a 3mm allowance on each side; during semi-finishing, the excess material of the upper and lower surfaces of the grooves is removed uniformly, leaving a 0.5mm allowance on each side; during finishing, the upper and lower surfaces are first machined to the required size, and the upper and lower surfaces of the grooves are then milled with the planes as a reference to ensure the parallelism between the groove surface and the upper and lower surfaces.

[0013] The beneficial effects of this invention are: by using equal-height shims with reasonable force distribution, and by arranging the process to loosen and flip the shims multiple times, perform clinical correction, control deformation, flexibly clamp, and perform step-by-step milling, the technical problems of large deformation, low processing efficiency, fast tool wear, low surface roughness, and low processing accuracy in cutting ultra-high precision slender and flat stainless steel thin-walled plates are solved. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the shape and position accuracy and surface roughness of the upper and lower planes of the thin-walled plate in this invention.

[0015] Figure 2 This is a schematic diagram of the shape and position accuracy and surface roughness of the groove plane on the side of the thin-walled plate in this invention.

[0016] Figure 3 This is a partially enlarged view of the groove on the lower plane of the thin-walled plate in this invention.

[0017] Figure 4 This is a schematic diagram of the placement of the medium-height shims and workpieces according to the present invention.

[0018] Figure 5 for Figure 4 A schematic diagram of the mounting plate inside the slot.

[0019] Figure 6 for Figure 4 The diagram shows the compression clamping process.

[0020] Figure 7 This is a structural diagram of the flipping fixture.

[0021] Figure 8 This is a schematic diagram of the groove spacing cutting of the present invention.

[0022] Among them: 1. pressure plate, 2. leveling pad, 3. workpiece. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1 to 8 The method for processing a high-precision, ultra-long, flat, thin-walled plate includes the following steps:

[0025] (1) Place the ultra-long flat parts on the casting mounting platform to improve the rigidity and shock resistance of the ultra-long flat parts mounting system. The casting mounting platform is a cast iron shim with a width not exceeding 5 times the plate thickness and a spacing not exceeding 2.5 times the plate thickness. The reasonable spacing can ensure heat dissipation of the parts and the rigidity of the mounting system.

[0026] (2) Clamping the super-long flat parts, rough and semi-finishing, using small cutting depth, fast feed and high speed milling, removing the four around large plane allowance symmetrically and uniformly, using multi-point evenly distributed side top clamping for processing plane, reducing the clamping force during plane milling, using side positioning for processing side groove, using multi-point evenly distributed pressing plate clamping for processing large plane and step surface and side groove;

[0027] (3) After each plane processing, using square wood to artificially vibrate and correct the shape of the part, and homogenizing the milling residual stress of the part;

[0028] (4) Hoisting the part through a special hoisting and turning over tool to reduce the deformation during hoisting and turning over;

[0029] (5) Processing the groove surface of the hoisted and turned over part, using interval processing (odd-even method) for the groove surface, and using one-cut-down method for uniformly removing the allowance of each step surface;

[0030] (6) According to the cutting performance of the thin-walled plate material, selecting the tool and cutting parameters, and controlling the deformation of rough and semi-finishing to be less than 0.5mm, and the deformation of finishing to be less than 0.2mm;

[0031] (7) Rough milling and leaving allowance for the two side grooves, each positioning pin hole and keyway of the part processed in the last step during semi-finishing of the four around large plane, and then finishing the two side groove surfaces after processing the four around plane to size,

[0032] (8) Processing each screw hole to position after semi-finishing, reducing the influence of drilling on the plane accuracy.

[0033] In the above technical scheme, in step (1), the equal-height iron pad of cast iron material with a width not more than 5 times the thickness of the thin-walled plate and a spacing not more than 2.5 times the thickness of the plate is used as the clamping and processing platform.

[0034] In the above technical scheme, in step (3), the distance between the lower end of the wooden square and the upper plane of the part is not more than 300mm during the correction, and the number of knocks each time is not less than 5. After each clamping and processing of the part, the clamping and pressing are loosened, which will cause deformation due to uneven stress distribution. To solve this problem, a wooden square with a size of 1000x80x80 is used for artificial knocking correction in the length direction with a spacing not more than 5 times the thickness of the plate. The artificial vibration aging method is used to homogenize the residual stress of the part and correct the deformation of the workpiece.

[0035] In the above technical scheme, in step (4), the part turning over is carried out at the first and last 2 / 9 positions of the part simultaneously using a turning over tool. The opening size of the turning over tool is designed to be 2mm larger than the thickness of the part blank, and the depth is not more than 4 / 5 of the width of the part.

[0036] In the above technical solution, in step (5), each step surface is removed by a uniform step method with one knife; each time the cutting depth is not greater than 0.3 mm, and the odd-numbered grooves are processed in turn, and after all the odd-numbered grooves are processed, the even-numbered grooves are processed in turn in the same way.

[0037] In the above technical solution, in step (6), during rough machining, the plane is turned over after being machined for 1-1.5 mm, and the symmetrical surface is machined, and the plane is turned over again after being machined for 1-1.5 mm, and the cycle operation is repeated.

[0038] During semi-finishing machining, the large plane is turned over after removing 0.5 mm, and the deformation is controlled to be not more than 0.2 mm. After turning over, the bottom gap needs to be filled, which can reduce the workpiece vibration during cutting and improve the cutting surface quality.

[0039] In the above technical solution, in step (7), during rough machining, the two side grooves are removed by a small cutting depth and multiple milling method with a three-flute slot milling cutter, and each surface is left with a 3 mm excess; during semi-finishing machining, the upper and lower plane excesses of the grooves are removed uniformly, and each surface is left with a 0.5 mm excess; during finishing machining, the upper and lower planes are machined to the required size, and the grooves are precisely milled based on the planes, so as to ensure the parallelism of the grooves and the upper and lower planes.

[0040] In step (2), during finishing machining, the two side grooves are clamped by the inner clamping plate, the conventional clamping plate is modified into a clamping plate 1 which can be directly pressed into the groove, so as to reduce the number of clamping plate replacement, and the parallelism of the upper and lower planes can be better guaranteed. The workpiece 3 is fixed on the equal-height anvil 2 by the two clamping plates 1.

[0041] The above is only a preferred embodiment of the present application, but the protection scope of the present application is not limited thereto, any changes or replacements within the technical range disclosed by the present application can be easily thought by those skilled in the art, and should be covered within the protection scope of the present application.

Claims

1. A method for processing high-precision ultra-long flat thin-walled plates, characterized by: It comprises the following steps: (1) using the equal-height gasket iron of cast iron material with the width not more than 5 times of the plate thickness and the spacing not more than 2.5 times of the plate thickness as the clamping platform, the super-long flat parts are placed on the clamping platform of the castings, the rigidity and the shock resistance of the clamping system of the super-long flat parts are improved; (2) the clamped super-long flat parts are roughed and semi-finished, the small cutting depth, fast feeding and high-speed milling are adopted to remove the surplus of the four large planes symmetrically and uniformly; after the processing of 1-1.5 mm of each large plane, the plane is turned over, the symmetric plane is processed, and the same processing is repeated, the parts are lifted by the special lifting and turning-over tooling to reduce the deformation during lifting and turning-over; according to the cutting performance of the thin-walled plate material, the tool and the cutting parameters are selected to control the deformation of the roughing and semi-finishing to be less than 0.5 mm, the grooves on both sides of the parts, the positioning pin holes and the key grooves are roughed and surplus is left during the semi-finishing of the four large planes; after the semi-finishing is completed, the screw holes are processed in place to reduce the influence of drilling on the plane accuracy; after the four large planes are processed to the size, the two-side groove faces are finished, and the deformation of the finishing is controlled to be less than 0.2 mm; The multi-point uniform distribution side and top clamping is adopted for the processing of the plane to reduce the clamping force during the plane milling, the side positioning is adopted for the processing of the side groove, and the multi-point uniform distribution clamping of the pressing plate is adopted for the processing of the large plane and the step face and the side groove; After the processing of each plane is completed, the wooden square is used to artificially vibrate the parts to homogenize the milling residual stress of the parts; The groove faces of the parts after lifting and turning-over are processed by the interval processing of the groove faces, the step faces are uniformly removed by the one-time cutting method, the cutting depth is not greater than 0.3 mm, the odd-numbered grooves are processed in turn, and after the processing of all the odd-numbered grooves is completed, the even-numbered grooves are processed in turn by the same method.

2. The method of claim 1, wherein the high-precision ultra-long flat thin-wall plate is characterized in that: In step (2), the distance between the lower end of the wooden square and the upper plane of the part is not greater than 300 mm during the shaping, and the number of blows is not less than 5 times each time.

3. The method of claim 1, wherein the high-precision ultra-long flat thin-wall plate is characterized in that: In step (2), the turning-over tooling is used for the turning-over of the parts, the turning-over tooling is designed as a 2mm-opening-size, 4 / 5-depth-of-the-part-width ￠-shaped opening clamp.

4. The method of claim 1, wherein the high-precision ultra-long flat thin-wall plate is characterized in that: In step (2), the three-flute slot milling cutter is used for the roughing of the two-side grooves with small cutting depth and multiple milling, and the surplus of each face is 3mm; the semi-finishing is processed by uniformly removing the surplus of the upper and lower planes of the groove, and the surplus of each face is 0.5mm; during the finishing, the upper and lower planes are processed to the requirements, the upper and lower planes of the groove are finished by taking the planes as the reference to ensure the parallelism of the groove faces and the upper and lower planes.

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