Processing method for bottom plate of temper mill

Abstract

The invention discloses a temper mill bottom plate machining method which comprises the following specific steps that S100, appearance inspection is conducted on a bottom plate blank, and whether cracks and sand hole defects exist on the surface or not is checked; proper machining allowance is reserved according to the design size of the bottom plate; s200, a horizontal boring and milling machine is adopted, a hard alloy cutter is selected, and rough machining is conducted on the base plate blank in a multi-cutter and multi-blade milling mode; s300, the base plate obtained after rough machining is placed in an aging treatment furnace, the temperature is increased to 550-600 DEG C at the speed of 50-60 DEG C per hour, heat preservation is conducted for 4-6 hours, then the base plate is slowly cooled to the room temperature at the speed of 30-40 DEG C per hour, and therefore internal stress generated by rough machining is eliminated; s400, a horizontal boring and milling machine is adopted for conducting semi-finish machining on the bottom plate subjected to aging treatment; s500, carrying out vibration aging treatment on the semi-finished bottom plate by adopting vibration aging equipment; and S600, a high-precision numerical control grinding machine and a boring and milling machine are adopted for conducting finish machining on the bottom plate subjected to vibration aging treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of planishing machine processing, and specifically to a processing method for the bottom plate of a planishing machine. Background Art

[0002] In the processing of the bottom plate of a planishing machine, the length of the bottom plate is 4000 mm, the height is 350 mm, and the material is ZG270-500. How to ensure that the final processed product meets the requirements of the drawing has high requirements for the machine tool and the operator's level. The accuracy of the machine tool, the professional skill level of the operator, proper clamping, and appropriate feed will directly affect the final processing accuracy of the bottom plate.

[0003] The prior invention patent with the publication number CN109465605A discloses a processing technology for a wear-resistant bottom plate, and its technological steps mainly include the following: blanking, pressing, heat treatment, chamfering, and leveling. This processing technology is used for the processing of wear-resistant bottom plates and can effectively improve the wear resistance of the bottom plates. The key point of processing the bottom plate of a planishing machine is not wear resistance, but that the two bottom plates of the planishing machine need to maintain the same size. In the actual processing process, there are the following problems in the method for processing the bottom plate of a planishing machine: 1. When using the traditional pressing plate fixing method for processing, the pressing force of the pressing plate causes elastic deformation of the bottom plate, and the release of stress after processing causes springback, making it difficult to control flatness and parallelism. The deformation amount usually exceeds 0.1 mm and cannot meet the high-precision requirements. 2. When processing single pieces, the clamping error of different bottom plates and the difference in thermal deformation of the machine tool result in poor height dimension consistency, and the height difference between the two bottom plates often exceeds 0.05 mm. 3. There is a lack of a stress release process in stages. The stress concentration after rough machining is not effectively eliminated, and deformation is likely to occur due to the redistribution of stress during subsequent processing. Summary of the Invention

[0004] The purpose of the present invention is to provide a processing method for the bottom plate of a planishing machine, which solves the problems of deformation control and dimensional consistency in the processing of the bottom plate through a staged processing technology, an innovative support method, and stress control technology.

[0005] The present invention is implemented as follows:

[0006] A processing method for the bottom plate of a planishing machine, and the specific steps of this processing method are as follows:

[0007] S100. Conduct an appearance inspection on the bottom plate blank to check whether there are cracks and sand hole defects on the surface; and according to the design dimensions of the bottom plate, reserve an appropriate machining allowance;

[0008] S200. Use a horizontal boring and milling machine, select cemented carbide tools, and rough-machine the bottom plate blank by means of multi-tool and multi-edge milling;

[0009] S300. Place the rough - machined base plate in an aging furnace, heat it up to 550 - 600 °C at a rate of 50 - 60 °C per hour, hold for 4 - 6 hours, and then slowly cool it to room temperature at a rate of 30 - 40 °C per hour to eliminate the internal stress generated during rough machining.

[0010] S400. Perform semi - finishing on the base plate after aging treatment using a horizontal boring and milling machine.

[0011] S500. Perform vibration aging treatment on the semi - finished base plate using a vibration aging device.

[0012] S600. Perform finish machining on the base plate after vibration aging treatment using a high - precision CNC grinding machine and a boring and milling machine. When machining the base plate with the boring and milling machine, support the base plate in a way of using a spacer block and do not use a clamping plate to fix it, so as to eliminate the elastic deformation caused by the clamping plate pressure.

[0013] Preferably, when rough - machining the base plate blank in step S200, the spindle speed of the boring and milling machine is set to 180 - 220 r / min, the feed rate is 0.3 - 0.5 mm / r, the depth of cut is 3 - 5 mm, and each surface of the base plate is rough - milled to a unilateral allowance of 3 - 4 mm. During rough machining, coolant is used for cooling and lubrication. The coolant is a water - based cutting fluid with a concentration of 5% - 8%. By recycling the coolant, cutting heat and chips are removed, tool wear is reduced, and the machining surface quality is improved.

[0014] Preferably, the specific steps for semi - finishing the base plate in step S400 are as follows:

[0015] S410. Use an indexable end - mill, with the spindle speed of the boring and milling machine being 220 - 260 r / min, the feed rate being 0.2 - 0.3 mm / r, and the depth of cut being 1 - 2 mm. Rough - mill the base plate with the unilateral allowance controlled within 1 - 1.5 mm. The machining allowance distribution formula is

[0016]

[0017] where Z 1 is the unilateral allowance after semi - finishing, a i is the deformation coefficient of the i - th machining, F i is the cutting force of the i - th machining, E is the material elastic modulus, L is the length of the base plate, and b is the width of the base plate.

[0018] S420. Use a coated carbide milling cutter. The spindle speed of the boring and milling machine is 260 - 300 r / min, the feed rate is 0.1 - 0.2 mm / r, and the depth of cut is 0.5 - 1 mm to achieve a unilateral allowance of 0.3 - 0.5 mm for finish milling the bottom plate; finish milling adopts constant linear speed control technology; according to the change of the tool diameter and the machining position, the spindle speed is automatically adjusted to keep the linear speed of the tool cutting edge constant, thus ensuring the consistency and surface finish of the machined surface.

[0019] Preferably, when performing vibration aging treatment on the bottom plate in step S500, the excitation frequency of the vibration aging equipment is 30 - 60 Hz, and the excitation time is 20 - 30 minutes to further eliminate the residual stress generated during semi-finishing; the resonance frequency formula of vibration aging is:

[0020]

[0021] where f is the excitation frequency, K is the stiffness of the bottom plate, M is the mass of the bottom plate, β is the temperature correction coefficient, ΔT is the change in the aging environment temperature, and T 0 is the standard temperature. By controlling 30 ≤ f ≤ 60 Hz, the reduction of residual stress is ≥ 30%.

[0022] Preferably, the steps for finish machining the bottom plate in step S600 are as follows:

[0023] S610. Use a high-precision CNC grinding machine to process the bottom plate by grinding; select a ceramic bond grinding wheel with a grinding wheel grit size of 80 - 100 mesh. During grinding, the linear speed of the grinding wheel is 30 - 35 m / s, the feed speed of the workbench is 5 - 10 m / min, and the grinding depth is 0.01 - 0.03 mm to ensure that the flatness, parallelism, and perpendicularity errors of the bottom plate are ≤ 0.02 mm; during the grinding process, the grinding wheel is trimmed in real time. Use a diamond roller truing device to trim the grinding wheel with a truing depth of 0.02 - 0.05 mm and a feed speed of 0.1 - 0.2 mm / r to ensure that the grinding wheel always maintains a sharp cutting edge;

[0024] S620. Mark the areas on the workbench of the boring and milling machine for placing two bottom plates, and install eight pads in each area for placing the bottom plates, and ensure that the upper surfaces of the pads are on the same horizontal plane; then place the two bottom plates on the pads in the corresponding areas respectively;

[0025] S630. After the bottom plate is placed stably, use a feeler gauge and the light transmission method to detect the gap between the bottom plate and the pad. The feeler gauge of 0.02 cannot enter; for the light transmission method, use a flashlight to illuminate one side of the pad, and if no light can be seen on the other side of the pad, it is considered qualified. The flatness error accumulation formula is:

[0026]

[0027] Among them, δ flat is the flatness error, F i is the machining force at the i-th time, L is the length of the bottom plate, E is the elastic modulus of the material, I is the moment of inertia of the bottom plate cross-section, α is the coefficient of thermal expansion, and ΔT i is the temperature change during the i-th machining. δ is controlled by this formula flat ≤0.02 mm;

[0028] S640. Adopt the boring process and use a precision boring tool. During boring, the spindle speed is 300 - 350 r / min, and the feed rate is 0.05 - 0.1 mm / r to ensure the dimensional accuracy and position accuracy of the holes. The hole diameter tolerance is controlled within ±0.01 mm, and the hole pitch tolerance is controlled within ±0.02 mm. In this way, the hole system of the bottom plate is machined; during the hole system machining process, the tool compensation technology is adopted. By measuring the actual size and wear condition of the tool, the radius and length of the tool are compensated to improve the machining accuracy of the holes; the calculation formula for the position accuracy of the hole system is:

[0029]

[0030] Among them, ΔP is the hole pitch error, ΔX / ΔY / ΔZ are the three-coordinate positioning errors, θ is the perpendicularity deviation of the machine tool spindle, and L is the hole center distance. The hole pitch tolerance ΔP is controlled by this formula ≤ ±0.02 mm.

[0031] 6. A method for machining a bottom plate of a planishing machine according to any one of claims 1 - 5, characterized in that it further includes step S700. Use a three-coordinate measuring instrument to comprehensively detect the dimensional accuracy, shape accuracy, and position accuracy of the bottom plate; if the detection result exceeds the tolerance range, according to the deviation situation, adopt the method of fitter scraping or micro-grinding for correction until all the accuracy indexes of the bottom plate meet the design requirements; the dimension compensation formula during the inspection and correction process is:

[0032]

[0033] Among them, H 修正 is the height after correction, H 实测 is the measured height, δ j is the machining deformation at the j-th place, L j is the length of the machining area at the j-th place, L is the total length of the bottom plate, and E j is the local elastic modulus of the material at the j-th place. The height dimension correction accuracy is achieved to be ≤ ±0.01 mm by this formula.

[0034] Preferably, the cushion block in step S600 includes a support block, a chuck is provided below the support block, and the support block and the chuck are connected by a compression bolt.

[0035] Preferably, a second counterbore is provided in the middle of the support block. The cross-section of the chuck is T-shaped, and a second threaded groove is provided at the top end of the chuck. The pressing bolt passes through the second counterbore and is threadedly connected to the second threaded hole of the chuck. The top surface of the pressing bolt is lower than the upper surface of the support block.

[0036] Preferably, the cushion block further includes a bottom support plate. Adjusting screws are rotatably connected to both sides of the support block. The bottom end of the adjusting screw is threadedly connected to the bottom support plate. The top end of the adjusting screw is lower than the upper surface of the support block.

[0037] Preferably, first counterbores are symmetrically provided on both sides of the support block. Bearings are provided at the bottoms of the first counterbores. A transfer shaft is provided at the top end of the adjusting screw. The transfer shaft is in interference connection with the bearing. A bolt head is provided at the top end of the transfer shaft for rotating the adjusting screw. A through hole is provided in the middle of the bottom support plate for the pressing bolt to pass through the bottom support plate. Slots are symmetrically provided on both sides at the bottom of the support block. Plug-in blocks are symmetrically provided on both sides of the upper surface of the bottom support plate. A first threaded groove is provided in the middle of the top end of the plug-in block. The adjusting screw is threadedly connected to the first threaded groove.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] 1. By placing two blanks to be processed on the gantry boring and milling machine at the same time, the present invention can process the two bottom plates simultaneously, solving the problem of dimensional differences in traditional single-piece processing. And by releasing the allowance in stages and using natural support without a pressing plate, the deformation of the bottom plate is controlled within 0.02 mm, and the flatness, parallelism, and perpendicularity errors are ≤ 0.02 mm.

[0040] 2. By turning the workpiece over and correcting the deformation multiple times in the semi-finishing stage, the present invention reduces the subsequent processing difficulty. In the finishing process, a finishing cutter head is used, and the surface finish of Ra1.6 is achieved in one processing, avoiding secondary polishing.

[0041] 3. By detecting the coplanarity of the cushion block and using the method of light transmission with a feeler gauge to ensure the support accuracy, the present invention reduces the dependence on the experience of operators and improves the processing reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a flow block diagram of the processing method of the present invention;

[0043] Figure 2 is a top view of the cushion block of the present invention installed on the workbench of the boring and milling machine;

[0044] Figure 3 is a structural schematic diagram of the cushion block of the present invention;

[0045] Figure 4 is a structural schematic diagram of the support block of the present invention from the front-end oblique downward perspective;

[0046] Figure 5 It is a schematic structural view of the support block of the present invention from the rear inclined upward perspective;

[0047] Figure 6 It is a schematic structural view of the bottom support plate of the present invention;

[0048] Figure 7 It is a schematic structural view of the adjusting screw of the present invention;

[0049] Figure 8 It is a schematic structural view of the chuck of the present invention.

[0050] In the figure: 1, support block; 11, first counterbore; 12, bearing; 13, second counterbore; 14, slot; 2, bottom support plate; 21, insertion block; 22, first thread groove; 23, perforation; 3, adjusting screw; 31, adapter shaft; 32, bolt head; 4, chuck; 41, second thread groove; 5, compression bolt. Detailed implementation manners

[0051] In the present invention, unless otherwise clearly specified and defined, the terms "installation", "connection", "connection", "fixation" and other terms shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0052] The following will be further described in conjunction with the drawings and specific embodiments:

[0053] Embodiment 1

[0054] As Figure 1 and Figure 2 shown, a method for machining the bottom plate of a planishing machine, the specific steps of the machining method are as follows:

[0055] S100. Perform an appearance inspection on the bottom plate blank to check whether there are cracks and sand hole defects on the surface; and according to the design dimensions of the bottom plate, reserve an appropriate machining allowance, and control the unilateral machining allowance between 5 - 7 mm; the material of the bottom plate blank is ZG270 - 500.

[0056] S200. Use a horizontal boring and milling machine, select cemented carbide tools, and rough machine the blank of the bottom plate by multi-tool and multi-edge milling. When rough machining the blank of the bottom plate, set the spindle speed of the boring and milling machine at 180 - 220 r / min, the feed rate at 0.3 - 0.5 mm / r, and the depth of cut at 3 - 5 mm. Rough mill each surface of the bottom plate to a unilateral allowance of 3 - 4 mm. During rough machining, use coolant for cooling and lubrication. The coolant is a water-based cutting fluid with a concentration of 5% - 8%. Through the recycling of the coolant, take away the cutting heat and chips, reduce tool wear, and improve the machining surface quality.

[0057] S300. Place the rough-machined bottom plate in an aging furnace, heat it up to 550 - 600 °C at a rate of 50 - 60 °C per hour, hold for 4 - 6 hours, and then slowly cool it to room temperature at a rate of 30 - 40 °C per hour to eliminate the internal stress generated during rough machining.

[0058] S400. Use a horizontal boring and milling machine to semi-finish machine the bottom plate after aging treatment. The specific steps for semi-finishing the bottom plate are as follows:

[0059] S410. Use an indexable end mill, set the spindle speed of the boring and milling machine at 220 - 260 r / min, the feed rate at 0.2 - 0.3 mm / r, and the depth of cut at 1 - 2 mm. Control the unilateral allowance at 1 - 1.5 mm and rough mill the bottom plate. The machining allowance distribution formula is

[0060]

[0061] where Z 1 is the unilateral allowance after semi-finishing (mm), a i is the deformation coefficient of the i-th machining (0.8 ≤ a i ≤ 1.2), F i is the cutting force of the i-th machining (N), E is the material elastic modulus (E = 210 GPa), L is the length of the bottom plate (mm), and b is the width of the bottom plate (mm).

[0062] S420. Use a coated cemented carbide milling cutter, set the spindle speed of the boring and milling machine at 260 - 300 r / min, the feed rate at 0.1 - 0.2 mm / r, and the depth of cut at 0.5 - 1 mm. Finish mill the bottom plate to make the unilateral allowance reach 0.3 - 0.5 mm. Finish milling adopts the constant linear speed control technology. According to the change of the tool diameter and the machining position, automatically adjust the spindle speed to keep the linear speed of the tool cutting edge constant, so as to ensure the consistency and smoothness of the machining surface.

[0063] S500, the semi-finished bottom plate is subjected to vibration aging treatment by a vibration aging device; when the bottom plate is subjected to vibration aging treatment, the vibration aging device has an excitation frequency of 30-60Hz and an excitation time of 20-30 minutes to further eliminate the residual stress generated during the semi-finishing process; the vibration aging resonance frequency formula is:

[0064]

[0065] Where f is the excitation frequency (Hz), K is the base stiffness (N / m), M is the base mass (kg), and β is the temperature correction coefficient (β = 1.2 × 10 -5 ℃ -1 ), ΔT is the change of aging environment temperature (℃), T 0 For the standard temperature (20°C), the residual stress reduction of ≥30% is achieved by controlling 30≤f≤60Hz.

[0066] S600, use high-precision CNC grinders and boring and milling machines to finish the base plate after vibration aging treatment, and use pad support to support the base plate when the boring and milling machine processes the base plate without using a pressure plate to fix it, so as to eliminate the elastic deformation caused by the pressure of the pressure plate. The steps for finishing the base plate are as follows:

[0067] S610, adopts high-precision CNC grinding machine to process the bottom plate with grinding technology; selects ceramic bond grinding wheel with a grinding wheel particle size of 80-100 mesh. During grinding, the grinding wheel linear speed is 30-35m / s, the table feed speed is 5-10m / min, and the grinding depth is 0.01-0.03mm, ensuring that the bottom plate flatness, parallelism, and verticality errors are ≤0.02mm; during the grinding process, the grinding wheel is dressed in real time, using a diamond roller dresser to dress the grinding wheel at a dressing depth of 0.02-0.05mm and a feed speed of 0.1-0.2mm / r to ensure that the grinding wheel always maintains a sharp cutting edge;

[0068] S620. Define an area on the workbench of the boring and milling machine for placing two base plates, and install eight pads in each area for placing base plates (the pads are placed as shown in the figure). Figure 2 As shown), and ensure that the upper surfaces of the pads are on the same level; then place the two bottom plates on the pads in the corresponding areas respectively;

[0069] S630. After the base plate is stable, use the feeler gauge and light transmission method to check the gap between the base plate and the pad. The feeler gauge should not penetrate 0.02. The light transmission method uses a flashlight to illuminate one side of the pad. If no light can be seen on the other side of the pad, it is considered qualified. The cumulative formula for flatness error is:

[0070]

[0071] Among them, δ flat is the flatness error (mm), F i is the machining force of the i-th time (N), L is the length of the bottom plate (4000 mm), E is the elastic modulus of the material (210 GPa), I is the moment of inertia of the bottom plate cross-section (mm 4 ), α is the coefficient of thermal expansion (1.2×10 -5 ℃ -1 ), ΔT i is the temperature change of the i-th machining (℃), and δ f lat is controlled by this formula to be ≤0.02 mm.

[0072] S640. Adopt the boring process and use a precision boring tool. When boring, the spindle speed is 300 - 350 r / min, and the feed rate is 0.05 - 0.1 mm / r to ensure the dimensional accuracy and position accuracy of the hole. The hole diameter tolerance is controlled within ±0.01 mm, and the hole pitch tolerance is controlled within ±0.02 mm. The hole system of the bottom plate is machined in this way; during the hole system machining process, the tool compensation technology is adopted. By measuring the actual size and wear condition of the tool, the radius and length of the tool are compensated to improve the machining accuracy of the hole; the calculation formula for the position accuracy of the hole system is:

[0073]

[0074] Among them, ΔP is the hole pitch error (mm), ΔX / ΔY / ΔZ are the three-coordinate positioning errors (mm), θ is the perpendicularity deviation of the machine tool spindle (°), L is the hole center distance (mm), and the hole pitch tolerance ΔP is controlled by this formula to be ≤±0.02 mm.

[0075] Example 2

[0076] As Figure 1 and Figure 2 shown, a method for machining a leveling machine bottom plate, the specific steps of this machining method are as follows:

[0077] S100. Conduct an appearance inspection on the bottom plate blank to check whether there are cracks and sand hole defects on the surface; and according to the design dimensions of the bottom plate, reserve an appropriate machining allowance, and the unilateral machining allowance is controlled between 5 - 7 mm; the material of the bottom plate blank is ZG270 - 500.

[0078] S200. Use a horizontal boring and milling machine, select cemented carbide tools, and rough machine the bottom plate blank by multi-tool and multi-edge milling. When rough machining the bottom plate blank, set the spindle speed of the boring and milling machine to 180 - 220 r / min, the feed rate to 0.3 - 0.5 mm / r, and the depth of cut to 3 - 5 mm. Rough mill each surface of the bottom plate to a unilateral allowance of 3 - 4 mm. During rough machining, use coolant for cooling and lubrication. The coolant is a water-based cutting fluid with a concentration of 5% - 8%. Through the recycling of the coolant, remove the cutting heat and chips, reduce tool wear, and improve the machining surface quality.

[0079] S300. Place the rough-machined bottom plate in an aging furnace, heat it up to 550 - 600 °C at a rate of 50 - 60 °C per hour, hold for 4 - 6 hours, and then slowly cool it to room temperature at a rate of 30 - 40 °C per hour to eliminate the internal stress generated during rough machining.

[0080] S400. Use a horizontal boring and milling machine to semi-finish the bottom plate after aging treatment. The specific steps for semi-finishing the bottom plate are as follows:

[0081] S410. Use an indexable end mill. Set the spindle speed of the boring and milling machine to 220 - 260 r / min, the feed rate to 0.2 - 0.3 mm / r, and the depth of cut to 1 - 2 mm. Control the unilateral allowance within 1 - 1.5 mm and rough mill the bottom plate. The machining allowance distribution formula is

[0082]

[0083] where Z 1 is the unilateral allowance after semi-finishing (mm), a i is the deformation coefficient of the i-th machining (0.8 ≤ a i ≤ 1.2), F i is the cutting force of the i-th machining (N), E is the material elastic modulus (E = 210 GPa), L is the length of the bottom plate (mm), and b is the width of the bottom plate (mm).

[0084] S420. Use a coated cemented carbide milling cutter. Set the spindle speed of the boring and milling machine to 260 - 300 r / min, the feed rate to 0.1 - 0.2 mm / r, and the depth of cut to 0.5 - 1 mm. Finish mill the bottom plate to make the unilateral allowance reach 0.3 - 0.5 mm. Finish milling adopts the constant linear speed control technology. According to the change of the tool diameter and the machining position, automatically adjust the spindle speed to keep the linear speed of the tool cutting edge constant, so as to ensure the consistency and smoothness of the machining surface.

[0085] S500. Perform vibratory stress relief treatment on the semi-finished base plate using a vibratory stress relief equipment. When performing vibratory stress relief treatment on the base plate, the excitation frequency of the vibratory stress relief equipment is 30 - 60 Hz, and the excitation time is 20 - 30 minutes to further eliminate the residual stress generated during the semi-finishing process. The formula for the resonance frequency of vibratory stress relief is:

[0086]

[0087] where f is the excitation frequency (Hz), K is the stiffness of the base plate (N / m), M is the mass of the base plate (kg), β is the temperature correction coefficient (β = 1.2×10 -5 ℃ -1 ), ΔT is the change in the aging environment temperature (℃), T 0 is the standard temperature (20℃), and by controlling 30 ≤ f ≤ 60 Hz, the reduction of residual stress is ≥ 30%.

[0088] S600. Perform finish machining on the base plate after vibratory stress relief treatment using a high-precision CNC grinding machine and a boring and milling machine. When machining the base plate on the boring and milling machine, support the base plate in the form of using pads and do not use a clamping plate to fix it to eliminate the elastic deformation caused by the clamping plate pressure. The steps for finish machining the base plate are as follows:

[0089] S610. Use a high-precision CNC grinding machine to machine the base plate by grinding process; select a ceramic bond grinding wheel with a grinding wheel grit size of 80 - 100 mesh. When grinding, the grinding wheel linear speed is 30 - 35 m / s, the workbench feed speed is 5 - 10 m / min, and the grinding depth is 0.01 - 0.03 mm to ensure that the flatness, parallelism, and perpendicularity errors of the base plate are ≤ 0.02 mm; during the grinding process, perform real-time dressing on the grinding wheel. Use a diamond roller dresser to dress the grinding wheel with a dressing depth of 0.02 - 0.05 mm and a feed speed of 0.1 - 0.2 mm / r to ensure that the grinding wheel always maintains a sharp cutting edge;

[0090] S620. Mark the area on the workbench of the boring and milling machine for placing two base plates, and install eight pads in each area for placing the base plate (the placement method of the pads is as Figure 2 shown), and ensure that the upper surfaces of the pads are on the same horizontal plane; then place the two base plates on the pads in the corresponding areas respectively;

[0091] S630. After the base plate is placed stably, use a feeler gauge and the light transmission method to detect the gap between the base plate and the pad. The feeler gauge of 0.02 cannot enter; for the light transmission method, use a flashlight to illuminate on one side of the pad, and if no light can be seen on the other side of the pad, it is considered qualified. The cumulative formula for flatness error is:

[0092]

[0093] Among them, δ flat is the flatness error (mm), F i is the machining force at the i-th time (N), L is the length of the bottom plate (4000 mm), E is the elastic modulus of the material (210 GPa), I is the moment of inertia of the bottom plate cross-section (mm 4 ), α is the coefficient of thermal expansion (1.2×10 -5 °C -1 ), ΔT i is the temperature change at the i-th machining (°C), and δ f lat is controlled to be ≤0.02 mm through this formula.

[0094] S640. Adopt the boring process and use a precision boring tool. When boring, the spindle speed is 300 - 350 r / min, and the feed rate is 0.05 - 0.1 mm / r to ensure the dimensional accuracy and position accuracy of the hole. The hole diameter tolerance is controlled within ±0.01 mm, and the hole pitch tolerance is controlled within ±0.02 mm. The hole system of the bottom plate is machined in this way; during the hole system machining process, the tool compensation technology is adopted. By measuring the actual size and wear condition of the tool, the radius and length of the tool are compensated to improve the machining accuracy of the hole; the calculation formula for the hole system position accuracy is:

[0095]

[0096] Among them, ΔP is the hole pitch error (mm), ΔX / ΔY / ΔZ are the three-coordinate positioning errors (mm), θ is the perpendicularity deviation of the machine tool spindle (°), L is the hole center distance (mm), and the hole pitch tolerance ΔP is controlled to be ≤±0.02 mm through this formula.

[0097] S700. Use a three-coordinate measuring instrument to comprehensively detect the dimensional accuracy, shape accuracy, and position accuracy of the bottom plate; if the detection result exceeds the tolerance range, it is corrected by means of fitter scraping or micro-grinding according to the deviation situation until all the accuracy indexes of the bottom plate meet the design requirements; the dimension compensation formula during the inspection and correction process is:

[0098]

[0099] Among them, H 修正 is the corrected height (mm), H 实测 is the measured height (mm), δ j is the machining deformation at the j-th place (mm), L j is the length of the machining area at the j-th place (mm), L is the total length of the bottom plate (4000 mm), E j is the local elastic modulus of the material at the j-th place (GPa), and the height dimension correction accuracy is achieved to be ≤±0.01 mm through this formula.

[0100] Example 3

[0101] As shown Figure 3 in the figure, a spacer block for the processing of the bottom plate of a planishing machine is provided. The spacer block includes a support block 1, a chuck 4 is arranged below the support block 1, and the support block 1 and the chuck 4 are connected by a compression bolt 5; the chuck 4 is convenient for being clamped inside the groove of the workbench, so that the support block 1 is pressed against the workbench surface of the boring and milling machine by tightening the compression bolt 5, ensuring the stable use of the support block 1.

[0102] As shown Figure 4 and Figure 8 in the figure, a second counterbore 13 is arranged in the middle of the support block 1, and the second counterbore 13 is convenient for the compression bolt 5 to pass through the support block 1. The cross-section of the chuck 4 is T-shaped, and a second thread groove 41 is arranged at the top of the chuck 4. The compression bolt 5 passes through the second counterbore 13 and is threadedly connected to the second threaded hole of the chuck 4. This structure is convenient for the support block 1 to be stably connected to the chuck 4. The top surface of the compression bolt 5 is lower than the upper surface of the support block 1, which is used to prevent the top end of the compression screw from affecting the flatness of the bottom plate.

[0103] Example 4

[0104] As shown Figure 3 in the figure, a spacer block for the processing of the bottom plate of a planishing machine is provided. The spacer block includes a support block 1, a chuck 4 is arranged below the support block 1, and the support block 1 and the chuck 4 are connected by a compression bolt 5; the chuck 4 is convenient for being clamped inside the groove of the workbench, so that the support block 1 is pressed against the workbench surface of the boring and milling machine by tightening the compression bolt 5, ensuring the stable use of the support block 1.

[0105] As shown Figure 4 and Figure 8 in the figure, a second counterbore 13 is arranged in the middle of the support block 1, and the second counterbore 13 is convenient for the compression bolt 5 to pass through the support block 1. The cross-section of the chuck 4 is T-shaped, and a second thread groove 41 is arranged at the top of the chuck 4. The compression bolt 5 passes through the second counterbore 13 and is threadedly connected to the second threaded hole of the chuck 4. This structure is convenient for the support block 1 to be stably connected to the chuck 4. The top surface of the compression bolt 5 is lower than the upper surface of the support block 1, which is used to prevent the top end of the compression screw from affecting the flatness of the bottom plate.

[0106] As shown Figure 3 in the figure, the spacer block further includes a bottom support plate 2. Adjusting screws 3 are rotatably connected to both sides of the support block 1. The bottom ends of the adjusting screws 3 are threadedly connected to the bottom support plate 2, and the top ends of the adjusting screws 3 are lower than the upper surface of the support block 1; this structure is convenient for adjusting the position of the upper surface of the support block 1, so as to conveniently adjust the heights of multiple support blocks 1 to be the same, so that multiple support blocks 1 are on the same plane.

[0107] As shown Figure 4 , Figure 5 , Figure 6 and Figure 7As shown in the figure, first sunken holes 11 are symmetrically arranged on both sides of the support block 1. A bearing 12 is provided at the bottom of the first sunken hole 11. The cooperation between the first sunken hole 11 and the bearing 12 facilitates the rotation of the support block 1 and the adjusting screw rod 3. A transfer shaft 31 is provided at the top of the adjusting screw rod 3. The transfer shaft 31 is in interference connection with the bearing 12, which facilitates the adjusting screw rod 3 to drive the height of the bottom support plate 2 to be adjusted. A bolt head 32 is provided at the top of the transfer shaft 31 for rotating the adjusting screw rod 3. A through hole 23 is provided in the middle of the bottom support plate 2 for the pressing bolt 5 to pass through the bottom support plate 2. Slots 14 are symmetrically arranged on both sides at the bottom of the support block 1. The slots 14 facilitate the stable connection between the bottom support plate 2 and the support block 1. Insertion blocks 21 are symmetrically arranged on both sides of the upper surface of the bottom support plate 2. A first thread groove 22 is provided in the middle of the top of the insertion block 21. The adjusting screw rod 3 is threadedly connected to the first thread groove 22, which facilitates the adjustment of the bottom support plate 2 by driving the rotation of the adjusting screw rod 3.

[0108] Installation method: During use, according to the support requirements, gather the required cushion blocks together, and then through the adjustment of the adjusting screw rod 3, make the upper surfaces of the support blocks 1 all in the same plane. Then, snap the chuck 4 into the card slot inside the boring and milling machine workbench, and move the entire cushion block to the designated position. Then, tighten the pressing bolt 5 to make the cushion block stable on the boring and milling machine workbench. After that, measure the upper surface of the support block 1 again to ensure that the upper surfaces of the support blocks 1 are all in the same plane. If they are not in the same plane, fine-tuning can be performed using the adjusting screw rod 3.

[0109] In summary, compared with the prior art, in this application, two blanks to be processed are placed on the gantry boring and milling machine at the same time, so that the two bottom plates can be processed simultaneously, solving the problem of dimensional differences in traditional single-piece processing. And by releasing the allowance in stages and using natural support without a pressing plate, the deformation of the bottom plate is controlled within 0.02 mm, and the flatness, parallelism, and perpendicularity errors are ≤ 0.02 mm. By repeatedly turning and correcting the deformation during the semi-finishing stage, the subsequent processing difficulty is reduced. In the finish machining, a finishing blade cutter head is used, and the surface finish of Ra1.6 is achieved in one processing, avoiding secondary polishing. By detecting the coplanarity of the cushion blocks and using the light transmission method with a feeler gauge to ensure the support accuracy, the dependence on the experience of the operator is reduced, and the processing reliability is improved.

[0110] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for processing a bottom plate of a leveling machine, characterized in that: The specific steps of this processing method are as follows: S100. Perform an appearance inspection on the base plate blank to check whether there are cracks and sand holes on the surface; and reserve appropriate processing allowance according to the design size of the base plate; S200, using a horizontal boring and milling machine, using carbide tools, and rough machining the base plate blank by multi-cut multi-edge milling; S300, placing the rough-processed bottom plate in an aging treatment furnace, heating it to 550-600°C at a rate of 50-60°C per hour, keeping it warm for 4-6 hours, and then slowly cooling it to room temperature at a rate of 30-40°C per hour, so as to eliminate the internal stress caused by the rough processing; S400, using a horizontal boring and milling machine to perform semi-finishing processing on the base plate after aging treatment; S500, subjecting the semi-finished bottom plate to vibration aging treatment using vibration aging equipment; S600, use high-precision CNC grinders and boring and milling machines to finish the base plate after vibration aging treatment, and when the boring and milling machine processes the base plate, it uses pad support to support the base plate without using a pressure plate to fix it, so as to eliminate the elastic deformation caused by the pressure of the pressure plate.

2. A method for processing a flattening machine bottom plate according to claim 1, characterized in that: When the base plate blank is rough-machined in step S200, the spindle speed of the boring and milling machine is set to 180-220r / min, the feed rate is 0.3-0.5mm / r, the back cutting depth is 3-5mm, and each surface of the base plate is roughly milled to a single-side allowance of 3-4mm; during the rough machining process, coolant is used for cooling and lubrication; the coolant is a water-based cutting fluid with a concentration of 5%-8%. Through the circulation of the coolant, cutting heat and chips are taken away, tool wear is reduced, and the quality of the machined surface is improved.

3. A method for processing a flattening machine bottom plate according to claim 1, characterized in that: The specific steps of performing semi-finishing processing on the bottom plate in step S400 are as follows: S410, use indexable end mill, boring and milling machine spindle speed 220-260r / min, feed rate 0.2-0.3mm / r, back cutting depth 1-2mm, control the single side allowance at 1-1.5mm to perform rough milling on the base plate; the machining allowance distribution formula is Among them, Z1 is the single-side allowance after semi-finishing, a i is the deformation coefficient of the i-th processing, F i is the cutting force of the i-th machining, E is the elastic modulus of the material, L is the length of the base plate, and b is the width of the base plate; S420, using coated carbide milling cutter, boring and milling machine spindle speed of 260-300r / min, feed rate of 0.1-0.2mm / r, back cutting amount of 0.5-1mm, so that the single-side allowance reaches 0.3-0.5mm for fine milling of the base plate; fine milling adopts constant linear speed control technology; according to the changes in tool diameter and processing position, the spindle speed is automatically adjusted to keep the linear speed of the tool cutting edge constant, thereby ensuring the consistency and smoothness of the processed surface.

4. A method for processing a flattening machine bottom plate according to claim 1, characterized in that: When the base plate is subjected to vibration aging treatment in step S500, the vibration aging equipment has an excitation frequency of 30-60 Hz and an excitation time of 20-30 minutes, so as to further eliminate the residual stress generated during the semi-finishing process; the vibration aging resonance frequency formula is: Wherein, f is the excitation frequency, K is the base plate stiffness, M is the base plate mass, β is the temperature correction coefficient, ΔT is the aging environment temperature change, T0 is the standard temperature, and the residual stress reduction of ≥30% can be achieved by controlling 30≤f≤60Hz.

5. The method for processing a flattening machine bottom plate according to claim 1, characterized in that: The steps of finishing the bottom plate in step S600 are as follows: S610, adopts high-precision CNC grinding machine to process the bottom plate with grinding technology; selects ceramic bond grinding wheel with a grinding wheel particle size of 80-100 mesh. During grinding, the grinding wheel linear speed is 30-35m / s, the table feed speed is 5-10m / min, and the grinding depth is 0.01-0.03mm, ensuring that the bottom plate flatness, parallelism, and verticality errors are ≤0.02mm; during the grinding process, the grinding wheel is dressed in real time, using a diamond roller dresser to dress the grinding wheel at a dressing depth of 0.02-0.05mm and a feed speed of 0.1-0.2mm / r to ensure that the grinding wheel always maintains a sharp cutting edge; S620. Delimit areas for placing two base plates on the workbench of the boring and milling machine, and install eight pads in each area for placing the base plates, and ensure that the upper surfaces of the pads are on the same horizontal plane; then place the two base plates on the pads in the corresponding areas respectively; S630. After the base plate is stable, use the feeler gauge and light transmission method to check the gap between the base plate and the pad. The feeler gauge should not penetrate 0.

02. The light transmission method uses a flashlight to illuminate one side of the pad. If no light can be seen on the other side of the pad, it is considered qualified. The cumulative formula for flatness error is: Among them, δ flat is the flatness error, F i is the i-th processing force, L is the length of the base plate, E is the elastic modulus of the material, I is the moment of inertia of the base plate section, α is the thermal expansion coefficient, ΔT i is the temperature change of the i-th processing, and the formula is used to control δ flat ≤0.02mm; S640, adopts boring technology, uses precision boring tool, spindle speed is 300-350r / min, feed rate is 0.05-0.1mm / r, ensures the size accuracy and position accuracy of the hole, the hole diameter tolerance is controlled within ±0.01mm, the hole spacing tolerance is controlled within ±0.02mm, in this way, the hole system of the base plate is processed; in the process of hole system processing, tool compensation technology is used, by measuring the actual size and wear of the tool, the radius and length of the tool are compensated, and the processing accuracy of the hole is improved; the hole system position accuracy calculation formula is: Among them, ΔP is the hole spacing error, ΔX / ΔY / ΔZ are the three-coordinate positioning errors, θ is the verticality deviation of the machine tool spindle, and L is the hole center distance. The hole spacing tolerance ΔP is controlled by this formula to be ≤±0.02mm.

6. A method for processing a flattening machine bottom plate according to any one of claims 1 to 5, characterized in that: The method further includes step S700, using a three-coordinate measuring machine to comprehensively inspect the size accuracy, shape accuracy and position accuracy of the base plate; if the inspection result exceeds the tolerance range, correction is performed by bench scraping or micro-grinding according to the deviation until the accuracy indicators of the base plate meet the design requirements; the size compensation formula during the inspection and correction process is: Among them, H 修正 is the corrected height, H 实测 is the measured height, δ j is the machining deformation at the jth position, L j is the length of the jth processing area, L is the total length of the base plate, E j is the local elastic modulus of the material at the jth location. This formula is used to achieve a height dimension correction accuracy of ≤±0.01mm.

7. A method for processing a flattening machine bottom plate according to claim 1, characterized in that: The cushion block in step S600 comprises a support block (1), a clamping head (4) is provided below the support block (1), and the support block (1) and the clamping head (4) are connected by a clamping bolt (5).

8. A method for processing a flattening machine bottom plate according to claim 7, characterized in that: A second countersunk hole (13) is provided in the middle of the support block (1); the cross section of the clamp (4) is T-shaped, and a second threaded groove (41) is provided at the top of the clamp (4); the clamping bolt (5) passes through the second countersunk hole (13) and is threadedly connected to the second threaded hole of the clamp (4); and the top surface of the clamping bolt (5) is lower than the upper surface of the support block (1).

9. A method for processing a flattening machine bottom plate according to claim 7, characterized in that: The cushion block also includes a bottom support plate (2), and the two sides of the support block (1) are rotatably connected with adjustment screws (3), the bottom end of the adjustment screw (3) is threadedly connected to the bottom support plate (2), and the top end of the adjustment screw (3) is lower than the upper surface of the support block (1).

10. A method for processing a flattening machine bottom plate according to claim 9, characterized in that: The support block (1) is symmetrically provided with first countersunk holes (11) on both sides, a bearing (12) is provided at the bottom of the first countersunk hole (11), a transfer shaft (31) is provided at the top end of the adjusting screw (3), the transfer shaft (31) is interference-connected with the bearing (12), a bolt head (32) is provided at the top end of the transfer shaft (31) for rotating the adjusting screw (3); a through hole (23) is provided in the middle of the bottom support plate (2) for tightening the bolt (5) through the bottom support plate (2); slots (14) are symmetrically provided on both sides of the bottom of the support block (1), plug-in blocks (21) are symmetrically provided on both sides of the upper surface of the bottom support plate (2), a first thread groove (22) is provided in the middle of the top end of the plug-in block (21), and the adjusting screw (3) is threadably connected to the first thread groove (22).

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