A new process for machining a joint surface of a large water-hydrogen-cooled generator cooler

Abstract

A new process method for machining the joint surface of a large water-hydrogen-cooled generator cooler belongs to the technical field of machining. The method solves the problems of low machining efficiency and low precision in the prior art. The technical points are as follows: drawing a machining line; aligning the machining surface of the boring bar of the machine tool and the cooler cover; installing a rough milling blade, and rough machining the bottom surface of the cooler cover by adopting a back-shaped feed; stopping machining, and allowing the machine tool to idle for one night; installing a fine milling blade, and fine machining the bottom surface of the cooler cover. The application controls the runout of the disc milling cutter, changes the rough milling machining mode, combines the structure of the joint surface of the cooler, proposes a rough boring scheme, avoids intermittent cutting as much as possible in the process of the feed of the disc milling cutter, improves the rigidity, stability and motion precision of the machine tool, improves the product production efficiency, ensures the product machining precision, and saves the production cost.

Description

Technical Field

[0001] This invention relates to the field of machining technology, specifically a new process for machining the mating surface of a large water-hydrogen-cooled generator cooler. Background Technology

[0002] The machining of the mating surface of a large water-hydrogen cooled generator cooler presents extremely high technical challenges and stringent requirements. This mating surface serves as a critical sealing connection point after the cooler is assembled with the stator frame; its sealing performance directly affects the overall stability and safety of the generator's operation. Poor sealing can easily lead to serious malfunctions such as cooling medium leakage, thus demanding extremely high standards of machining precision.

[0003] In terms of surface roughness, it needs to meet high-precision surface finish standards to ensure that an effective sealing surface can be formed when the mating surfaces are in contact; the flatness needs to be strictly controlled within a very small tolerance range to ensure a tight fit when assembled with the stator frame.

[0004] However, current machining processes mostly employ intermittent cutting, which subjectes the cutting tool to frequent impact loads, placing higher demands on its hardness, toughness, and wear resistance. Intermittent cutting also affects the rigidity, stability, and motion accuracy of the machine tool. Due to factors such as high precision requirements, large machining areas, and intermittent cutting, the machining cycle is long, resulting in lower overall machining efficiency.

[0005] Therefore, there is an urgent need to propose a new process for machining the mating surface of a large water-hydrogen-cooled generator cooler to solve the problems of low machining efficiency and low precision in the existing technology. Summary of the Invention

[0006] In view of the above facts, in order to solve the problems of low processing efficiency and low precision in the prior art, the present invention designs a new process method for processing the mating surface of a large water-hydrogen cooled generator cooler.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A new process for machining the mating surface of a large water-hydrogen cooled generator cooler includes the following steps:

[0009] S1: Draw the processing line and check if the amount of incoming material processed in the previous step is sufficient;

[0010] S2: Place the cooler cover horizontally on the boring machine platform with the bottom side facing up, and support it with a V-block. The arc surface of the cooler cover should be in contact with the V-block.

[0011] S3: Based on the actual conditions of the site and the contact between the cooler cover and the V-shaped iron, select a suitable position on the cooler cover and weld the pressure block.

[0012] S4: Align the cooler cover according to the marked processing line and fix it with a pressing plate;

[0013] S5: Install several double-ended ejector rods to support between the inner part and the bottom surface of the cooler cover;

[0014] S6: Align the machining surfaces of the machine tool boring bar and the cooler cover;

[0015] S7: Install the rough milling blades of the face milling cutter, and thoroughly clean and wipe the contact surfaces during the installation of the face milling cutter tool;

[0016] S8: Install the rough milling blades on the machine tool, align them in both the static and rotating states of the rough milling blades, check and adjust the tool runout of the face milling cutter, and ensure that the tool runout values of the installed and adjusted face milling cutter tool are similar before machining;

[0017] S9: Rough-machine the bottom surface of the cooler cover using a "return" - shaped feed, from the outer frame to the inside, in a "return" shape;

[0018] S10: Stop machining and wait for fine machining when the ambient temperature is suitable the next day;

[0019] S11: Let the machine tool idle for one night to make the machine tool in a "hot" state;

[0020] S12: Install the fine milling blades of the face milling cutter, and thoroughly clean and wipe the contact surfaces during the installation of the face milling cutter tool;

[0021] S13: Install the fine milling blades on the machine tool, align them in both the static and rotating states of the fine milling blades, check and adjust the tool runout of the face milling cutter, and ensure that the tool runout values of the installed and adjusted face milling cutter tool are similar before machining;

[0022] S14: Perform fine machining on the bottom surface of the cooler cover.

[0023] Furthermore: In S4, align according to the marked processing line within 0.02 mm and fix the cooler cover according to this accuracy.

[0024] Furthermore: In S5, the assembly torque of the double-ended ejector rod support is 300 N·m, and the double-ended ejector rod support tightens the inner part and the bottom surface of the cooler cover.

[0025] Furthermore: In S8, after adjusting the tool runout of the face milling cutter, use the wrench corresponding to the rough milling blade and lock the rough milling blade according to the specified torque direction and magnitude.

[0026] Furthermore: In S9, for the "return" - shaped feed, take the vertical center line of the boring machine platform as the demarcation line, divide the bottom surface of the cooler cover into two machining areas, and when machining each area, the feed is a "return" - shaped route that progresses in circles from the outer frame to the inside;

[0027] First, quickly remove the machining allowance of the outer ring of the cooler cover, and then remove the machining allowance of the inner ring of the cooler cover until it is machined to the semi-finishing boring allowance.

[0028] Further: In S10, the ambient temperature is preferably such that the ambient temperature change on the second day does not exceed 6 - 8 °C.

[0029] Further: In S11, the machine tool runs continuously, and the rotational speed of the boring bar of the machine tool is constant, and the machining trajectory is constant.

[0030] Further: In S13, after adjusting the tool runout of the face milling cutter, use the wrench corresponding to the finishing milling insert and lock the finishing milling insert according to the specified torque direction and magnitude.

[0031] The beneficial effects of the present invention are as follows:

[0032] 1. By controlling the tool runout of the face milling cutter, changing the rough milling machining method, and combining with the structure of the cooler mating surface, the present invention proposes a rough boring scheme, and as much as possible avoids interrupted cutting during the feeding process of the face milling cutter, improving the rigidity, stability, and motion accuracy of the machine tool.

[0033] 2. The present invention avoids the influence of temperature on the equipment performance, the method is simple and effective, improves the production efficiency of the product, ensures the machining accuracy of the product, and saves the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is the clamping schematic diagram of the present invention;

[0035] Figure 2 is the positional relationship diagram of the cooler cover and the double-ended rod support in the present invention;

[0036] Figure 3 is the "return" - shaped machining trajectory diagram of the present invention.

[0037] In the figure: 1 - cooler cover, 2 - double-ended rod support, 3 - boring machine platform, 4 - V - block. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] In order to enable those skilled in the art of the present technology to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0039] The terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0040] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0041] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0042] Example: Figures 1-3 As shown in the figure, the new process method for machining the mating surface of a large water-hydrogen cooled generator cooler in this embodiment includes the following steps:

[0043] S1: Draw the processing line and check if the amount of incoming material processed in the previous step is sufficient;

[0044] S2: Place the cooler cover 1 horizontally on the boring machine platform 3 with the bottom side facing up, and support it with the V-shaped iron 4. The arc surface of the cooler cover 1 is in contact with the V-shaped iron 4.

[0045] S3: Based on the actual situation of the site and the contact between the cooler cover 1 and the V-shaped iron 4, select a suitable position on the cooler cover 1 and weld the pressure block.

[0046] S4: Align cooler cover 1 according to the marked machining line and fix it with the pressure plate;

[0047] S5: Several double-headed top rod supports 2 are installed between the inside and bottom surface of the cooler cover 1 to prevent deformation during processing;

[0048] S6: Align the machining surfaces of the machine tool boring bar and the cooler cover 1 to lay the foundation for subsequent adjustment of the disc milling cutter;

[0049] S7: Install the roughing insert of the disc milling cutter, and thoroughly clean and wipe the contact surface of the disc milling cutter during the installation process to avoid affecting the machining accuracy;

[0050] S8: Install the roughing insert on the machine tool, align it in both stationary and rotating states, check and adjust the runout of the disc milling cutter, and ensure that the runout values ​​of the installed and adjusted disc milling cutters are as close as possible before machining;

[0051] S9: Use a U-shaped feed to rough machine the bottom surface of the cooler cover 1, from the outer frame to the inside, in a U-shape, to avoid intermittent cutting as much as possible;

[0052] S10: Stop processing and wait for fine machining when the ambient temperature is suitable the next day to avoid the impact of ambient temperature on the performance of processing equipment;

[0053] S11: Let the machine tool idle for one night to make the machine tool in a "hot" state and keep the parameters as consistent as possible with those during machining the next day;

[0054] S12: Install the fine milling blade of the face milling cutter, and thoroughly clean and wipe the contact surface of the face milling cutter during installation to avoid affecting the machining accuracy;

[0055] S13: Install the fine milling blade on the machine tool, align it both when the fine milling blade is stationary and rotating, check and adjust the runout of the face milling cutter to ensure that the runout values of the installed and adjusted face milling cutter are as close as possible before machining;

[0056] S14: Carry out fine machining on the bottom surface of the cooler cover 1, avoiding the impact of temperature on the machine tool performance, avoiding the installation accuracy of the blade, and improving the product machining quality.

[0057] More specifically: In the said S4, align it within 0.02 mm according to the drawn processing line, and fix the cooler cover 1 according to this accuracy;

[0058] Since the cooler cover 1 is in the blank state at this time and machining has not started yet, if the alignment accuracy requirement is too high, it will lead to an increase in alignment cost and actual situation, which is not conducive to production efficiency improvement, and this accuracy is sufficient to meet the machining of this process.

[0059] More specifically: In the said S5, the assembly torque of the double-headed ejector support 2 is 300 N·m. The double-headed ejector support 2 tightens the inside and bottom surface of the cooler cover 1 to prevent machining deformation, and can also reduce the vibration during machining to avoid affecting the machining quality.

[0060] More specifically: In the said S8, after adjusting the runout of the face milling cutter, use the wrench corresponding to the rough milling blade and lock the rough milling blade according to the specified torque direction and magnitude to avoid damage to the face milling cutter, effectively reducing the vibration of the rough milling blade during machining, thereby improving the product machining quality.

[0061] More specifically: In the said S9, the "return" - shaped feed takes the vertical center line of the boring machine platform 3 as the dividing line, divides the bottom surface of the cooler cover 1 into two machining areas. When machining each machining area, the feed is in a "return" - shaped route of progressive circles. To avoid interrupted cutting, adopt a "return" - shaped machining route from the outer frame to the inside;

[0062] Adopting the "return" - shaped feed to machine the cooler cover 1 can avoid interrupted cutting as much as possible during the feed of the face milling cutter. First, quickly remove the machining allowance of the outer ring of the cooler cover 1, and then remove the machining allowance of the inner ring of the cooler cover 1 until machining to the semi - finish boring allowance;

[0063] Meanwhile, a fast feed method with a small cutting tool can be used to reduce cutting resistance, increase feed speed, and fully utilize the high-speed cutting performance of the roughing milling insert. Compressed air is used to cool the machined and unmachined surfaces during the machining process to reduce surface cutting heat and thus improve machining accuracy.

[0064] More specifically: In S10, the ambient temperature is suitable so that the change in ambient temperature on the second day does not exceed 6-8℃, so as to avoid the machine tool's stability from changing due to daytime temperature changes during the finishing process of the cooler cover 1, thereby affecting the processing quality;

[0065] Temperature changes affect the viscosity of the oil in the hydraulic system. As the temperature rises during the day, the viscosity of the oil decreases and its fluidity increases. Lower viscosity reduces the resistance of the oil in the lubrication system, resulting in a decrease in oil pressure.

[0066] Meanwhile, oil also has an expansive property. When the temperature rises, the oil volume will expand to a certain extent, leading to an increase in volume and pressure in the lubrication system. This increases the oil pressure, and the instability of the oil pressure has a particularly large impact on the floating stability of the machine tool column and boring box during the feed process. Therefore, it is necessary to pay attention to temperature changes during the day to avoid changes in the stability of the machine tool, which would affect the machining quality.

[0067] More specifically: In S11, the machine tool runs continuously, and the speed of the machine tool boring bar is constant, the machining trajectory is constant, and the equipment is kept as consistent as possible with the finishing process the next day to enhance the stability of the machine tool;

[0068] Before precision boring, the machine tool is in a "hot" state. On the one hand, this allows the machine tool operator to familiarize himself with the machining method for the next day. On the other hand, it prevents the machine tool's stability from changing due to temperature variations between day and night, which could affect the machining quality.

[0069] More specifically: In S13, after adjusting the runout of the disc milling cutter, a wrench corresponding to the finish milling insert is used, and the finish milling insert is tightened according to the specified torque direction and magnitude to avoid damage to the disc milling cutter, effectively reduce the vibration of the finish milling insert during machining, thereby improving the quality of product machining.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; as long as there is no structural conflict, the various features in the specific embodiments disclosed in this application can be combined with each other in any way, and will not cause the substance of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

[0071] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A processing method for the mating surface of a large water-hydrogen cooled generator cooler, characterized in that, The steps are as follows: S1: Mark the processing line and check whether the processing amount of the incoming materials from the previous process is sufficient; S2: Horizontally place the bottom surface of the cooler cover (1) upward on the boring machine platform (3) and support it with a V-block (4). The arc surface of the cooler cover (1) contacts the V-block (4); S3: Select a suitable position on the cooler cover (1) according to the site and the actual situation of the contact between the cooler cover (1) and the V-block (4), and weld the pressing block; S4: Align the cooler cover (1) according to the marked processing line and fix it with a pressing plate; S5: Set several double-headed ejector supports (2) between the inside and the bottom surface of the cooler cover (1); S6: Align the boring bar of the machine tool with the processing surface of the cooler cover (1); S7: Install the rough milling blades of the face milling cutter and thoroughly clean and wipe the contact surface of the face milling cutter during installation; S8: Install the rough milling blades on the machine tool, align them in both the stationary and rotating states of the rough milling blades, check and adjust the runout of the face milling cutter, and ensure that the runout values of the installed and adjusted face milling cutter are similar before processing; S9: Rough-machine the bottom surface of the cooler cover (1) using a "return" type feed, from the outer frame to the inside, in a "return" shape; S10: Stop processing and wait for fine machining when the ambient temperature is suitable the next day; S11: Let the machine tool idle for one night to make the machine tool in a "hot" state; S12: Install the fine milling blades of the face milling cutter and thoroughly clean and wipe the contact surface of the face milling cutter during installation; S13: Install the fine milling blades on the machine tool, align them in both the stationary and rotating states of the fine milling blades, check and adjust the runout of the face milling cutter, and ensure that the runout values of the installed and adjusted face milling cutter are similar before processing; S14: Perform fine machining on the bottom surface of the cooler cover (1).

2. The processing method for the mating surface of a large water-hydrogen cooled generator cooler according to claim 1, characterized in that, In S4, align it within 0.02 mm according to the marked processing line and fix the cooler cover (1) according to this precision.

3. The processing method for the mating surface of a large water-hydrogen cooled generator cooler according to claim 1, characterized in that, In S5, the assembly torque of the double-headed ejector support (2) is 300 N·m, and the double-headed ejector support (2) tightens the inside and the bottom surface of the cooler cover (1).

4. The processing method for the mating surface of a large water-hydrogen cooled generator cooler according to claim 1, characterized in that, ​ 5. The processing method for the mating surface of a large water-hydrogen cooled generator cooler according to claim 1, characterized in that, ​ ​ 6. The processing method for the mating surface of a large water-hydrogen cooled generator cooler according to claim 1, characterized in that, ​ 7. The processing method for the mating surface of a large water-hydrogen cooled generator cooler according to claim 1, characterized in that, ​ 8. The processing method for the mating surface of a large water-hydrogen cooled generator cooler according to claim 1, characterized in that, ​

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