Machining method for cambered surface valve seat of ore pulp plug valve

Abstract

The invention discloses a processing method of a cambered surface valve seat of an ore pulp plug valve, which comprises the following steps: in the processing of the cambered surface valve seat, carrying out linear cutting on a forge piece barrel material to obtain a semi-finished product of the cambered surface valve seat, and then carrying out artificial aging treatment. According to the method, stress generated in lathe machining, milling machine machining and linear cutting machining of the forge piece barrel material is eliminated through artificial aging treatment, so that the cambered surface valve seat has good stability, the precision of dimensional tolerance and form and location tolerance is remarkably improved, deformation in subsequent machining is blocked, and the stability of a product is solidified; in the outer circle grinding step and the inner hole grinding step, matched tools are adopted for assisting in grinding, so that the cambered surface valve seat and the tools are assembled into an integral structure with good rigidity in the machining process, the cutter relieving phenomenon of a grinding wheel in the grinding process is avoided, the grinding work is more stable, and the machining efficiency is improved. In the grinding process of the cambered surface valve seat, appearance defects and surface roughness value segmentation defects are avoided, and the dimensional precision of a finished cambered surface valve seat product is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of production technology of slurry plug valves, in particular to a method for processing a curved surface valve seat of a slurry plug valve. Background Art

[0002] In the prior art, the processing route of the arc valve seat of the slurry plug valve is usually: rough processing of the cylinder material-heat treatment-semi-finishing of the cylinder material-stress relief heat treatment-spraying-grinding the outer circle-grinding the inner circle-wire cutting; when the cylinder material is semi-finished, the processing of the flow channel window, spring groove and sealing ring groove on the arc valve seat is completed. Because the overall rigidity of the cylinder material is insufficient and there is a certain elasticity when the cylinder material is ground on the outer circle and inner circle, there will be some positions where intermittent cutting occurs when the grinding wheel is used for grinding. The cutting force will cause the grinding wheel to give up the knife, resulting in the appearance defects of ellipse or taper of the cylinder material after grinding, or the defect of segmented surface roughness value after grinding, so that the dimensional tolerance, shape and position tolerance or roughness value of the final arc valve seat product is difficult to meet the design requirements; in addition, the cylinder material will undergo unexpected deformation after wire cutting, and the arc valve seat will continuously release internal processing stress over time, resulting in increasing errors in dimensional tolerance and shape and position tolerance.

[0003] The Chinese invention patent application with publication number CN114670085A discloses a processing fixture and processing method for a plug valve seat, and the technical solution of the processing method includes: processing a blank so that the blank forms the inner arc surface; marking the blank so that the blank is aligned and fixed on the processing fixture; fixing two blanks to be fine-ground on the processing fixture, and installing the two blanks in the processing space with the inner arc surfaces of the two blanks facing each other, entering between the inner arc surfaces of the two blanks through a grinding wheel, and fine-grinding the inner arc surfaces of the two blanks at the same time to form a valve seat.

[0004] In the technical solution of the above patent, the valve seat blank of the plug valve is fixed by a processing fixture and then fine-ground. The grinding accuracy of the inner arc surface of the valve seat is controlled mainly by fixing and positioning the valve seat blank, but it cannot solve the stress problem caused by wire cutting. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for processing a curved valve seat of a slurry plug valve, which can effectively improve the stability of the product and further improve the shape and position tolerance accuracy and dimensional tolerance accuracy of the product.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is: a method for processing a curved valve seat of a slurry plug valve, in which a semi-finished curved valve seat is obtained by wire cutting the forging tube material and then subjected to artificial aging treatment.

[0007] As an improvement to the above solution, perform the following steps in sequence:

[0008] Step 1: Rough turning the forging tube material to leave machining allowance on each side of the forging tube material;

[0009] Step 2: heat-treating the forging tube material by using solid solution treatment and aging hardening treatment;

[0010] Step 3: semi-finish turning the forging tube;

[0011] Step 4: Mill out the reference line, groove and window on the forging tube;

[0012] Step 5: Milling pin holes on the forging tube;

[0013] Step 6: Perform wire cutting on the forging barrel to decompose the forging barrel into three semi-finished products of the arc surface valve seat;

[0014] Step 7: Perform artificial aging treatment on the arc surface valve seat, heat the arc surface valve seat to 200-250°C and keep it warm for at least 4 hours, and then cool it to room temperature;

[0015] Step 8: Use the outer circle grinding tool to roughly grind the outer circle of the arc surface valve seat;

[0016] Step 9: Use inner hole grinding tool to roughly grind the inner hole of the arc surface valve seat;

[0017] Step 10: Chamfer the flow channel window of the arc valve seat;

[0018] Step 11: Detect flaws on the inner surface of the arc of the arc valve seat;

[0019] Step 12: Spraying alloy on the arc surface valve seat;

[0020] Step 13: Use the inner hole grinding tool in step 9 to finely grind the inner hole of the arc surface valve seat;

[0021] Step 14: Use the outer circle grinding tool in step 8 to finely grind the outer circle of the arc surface valve seat;

[0022] Step 15: Detect the sprayed surface of the arc valve seat;

[0023] Step 16: Conduct quality inspection on the finished product size of the curved valve seat.

[0024] As an improvement of the above scheme: in the step 1, after rough turning, a machining allowance of 3 mm is left on each side of the forging tube material.

[0025] As an improvement of the above scheme: in the step three, the forging barrel is semi-finished turned so that the outer diameter and the inner diameter of the forging barrel have a single-side grinding allowance of 1 mm, so that the remaining dimensions of the forging barrel meet the design dimensions of the arc valve seat.

[0026] As an improvement of the above scheme: in the steps eight and fourteen, the outer circle grinding tooling used includes a rotary shaft and two sets of clamps; the rotary shaft consists of a positioning sleeve, a first outer end cover and a second outer end cover, the first outer end cover and the second outer end cover are coaxially arranged with the positioning sleeve and are respectively detachably connected to the two ends of the positioning sleeve, a toggle stud is fixed on the outer end surface of the first outer end cover, and a top hole is provided in the center of the outer end surface of the first outer end cover and the second outer end cover; the clamp consists of two semicircular clamps that are detachably connected; when assembling with the arc surface valve seat, the two arc surface valve seats are placed against the outer surface of the positioning sleeve, and the two arc surface valve seats are symmetrical with respect to the central axis of the positioning sleeve as a reference, the arc surface valve seat forms a positioning match with the first outer end cover and the second outer end cover through a positioning structure composed of a positioning pin and a positioning hole, and the two ends of the arc surface valve seat form an axial limit match with the first outer end cover and the second outer end cover respectively, and the two sets of clamps are respectively sleeved on the two ends of the arc surface valve seat and the arc surface valve seat is clamped on the positioning sleeve.

[0027] As an improvement of the above scheme: in the steps 9 and 13, the inner hole grinding tooling used includes a positioning sleeve, a third outer end cover, a fourth outer end cover, two support blocks and two sets of tensioning components; the third outer end cover and the fourth outer end cover are coaxially arranged with the positioning sleeve and are detachably connected to the two ends of the positioning sleeve respectively; the support block has an arc surface adapted to the inner surface of the arc surface valve seat, and a limiting groove is provided on the other side of the support block relative to the arc surface; when assembling with the arc surface valve seat, the fourth outer end cover is fixed on the positioning sleeve, and the two arc blocks are fixed to the positioning sleeve. The arc valve seat is set against the inner surface of the locating sleeve, and the two arc valve seats are symmetrical with respect to the central axis of the locating sleeve. The arc valve seat forms a positioning match with the fourth outer end cover through a positioning structure composed of a positioning pin and a positioning hole. The two support blocks are respectively set against the inner surfaces of the two arc valve seats and the two support blocks are tightened on the corresponding arc valve seats using a jack. The two sets of tensioning components are respectively inserted into the gap between the two arc valve seats. After removing the jack and the support block, the third outer end cover is fixed on the locating sleeve.

[0028] As an improvement of the above scheme: the tensioning assembly includes two wedge blocks, which are arc-shaped blocks with beveled edges. The two wedge blocks are inserted between two arc-shaped valve seats to form a limit fit; the arc surface of the wedge block is adapted to the inner surface of the positioning sleeve.

[0029] As an improvement of the above scheme: in the step twelve, the spray alloy adopts HV0 supersonic spraying of tungsten carbide coating, the temperature of the arc valve seat is maintained at less than 200°C during the spraying process, and the processing allowance of the coating is 0.3mm on one side.

[0030] The beneficial effects of the present invention are as follows: the present invention improves the processing method of the arc valve seat of the slurry plug valve, performs artificial aging treatment after the arc valve seat blank is obtained by wire cutting the forging cylinder, and eliminates the stress generated by the forging cylinder during lathe processing, milling machine processing and wire cutting processing through artificial aging treatment, so that the arc valve seat has good stability, the accuracy of dimensional tolerance and shape and position tolerance is significantly improved, the occurrence of deformation in subsequent processing is blocked, and the stability of the product is solidified; the present invention adopts suitable tooling to assist in grinding in the steps of grinding the outer circle and grinding the inner hole, so that the arc valve seat and the tooling are assembled into an integral structure with good rigidity during the processing process, the phenomenon of the grinding wheel giving way during the grinding process is avoided, the grinding work is more stable, the arc valve seat will not have shape defects and surface roughness value segmentation defects during the grinding process, and the dimensional accuracy of the arc valve seat finished product is effectively improved; the process route of the present invention is clear, the process is simple, and the tooling fixture used is easy to manufacture, easy to operate, unified positioning reference, and accurate positioning size. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the arc surface valve seat of the slurry cock valve;

[0032] Figure 2 A schematic diagram of the structure of the forging barrel used for machining the curved valve seat;

[0033] Figure 3 This is the front view after the outer circle grinding tooling and the arc surface valve seat are assembled;

[0034] Figure 4 This is the side view after the outer circle grinding tooling and the arc surface valve seat are assembled;

[0035] Figure 5 This is the axonometric view after the external cylindrical grinding tooling and the curved valve seat are assembled;

[0036] Figure 6 This is a side view of the inner hole grinding tool and the arc surface valve seat during assembly;

[0037] Figure 7 This is the axonometric view of the inner hole grinding tooling and the arc surface valve seat during assembly;

[0038] Figure 8 This is a cross-sectional view of the inner hole grinding tooling and the arc surface valve seat after assembly;

[0039] Fig. 9 is a structural schematic diagram of the support block;

[0040] Fig.10 It is a structural schematic diagram of the tensioning component.

[0041] Marked in the figure: 100-arc valve seat, 200-forging cylinder material, 300-external grinding tooling, 310-rotating shaft, 311-positioning sleeve, 312-first outer end cover, 313-second outer end cover, 314-sliding stud, 320-hoop, 400-inner hole grinding tooling, 410-positioning sleeve, 420-third outer end cover, 430-fourth outer end cover, 440-support block, 450-wedge block, 460-jack. DETAILED DESCRIPTION

[0042] In order to facilitate the understanding of the present invention, the present invention is further described below in conjunction with the accompanying drawings.

[0043] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as “front”, “rear”, “left”, “right”, “up”, “down”, and “inside” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of description. They do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0044] The processing method of the arc surface valve seat of the slurry plug valve of the present invention is used for processing Figure 1 The arc surface valve seat 100 of the slurry cock valve shown in FIG. 1 is an arc-shaped plate structure similar to a tile shape. The forging cylinder material 200 used to process the arc surface valve seat 100 is as shown in FIG. Figure 2 In order to eliminate the stress released in the process of obtaining the semi-finished product of the arc surface valve seat 100 by wire cutting the forging barrel 200 and prevent deformation caused by the stress release, the present invention improves the processing method of the arc surface valve seat 100. In the processing of the arc surface valve seat 100, after the forging barrel 200 is wire cut to obtain the semi-finished product of the arc surface valve seat 100, artificial aging treatment is performed, thereby eliminating the stress release caused by the wire cutting of the forging barrel 200, achieving the effect of stabilizing the product size and stopping the product size from continuing to change, and can effectively improve the finished product size accuracy of the arc surface valve seat 100.

[0045] Specifically, the processing method of the arc surface valve seat of the slurry plug valve disclosed in the present invention is carried out according to the following steps:

[0046] Step 1: Rough turning the forging barrel 200 so that machining allowances are left on each side of the forging barrel 200. During rough turning, first clamp the outer circle of one end of the forging barrel 200 through the chuck of the lathe, make the end face of the other end of the forging barrel 200 roughly flat and calibrate the outer diameter of the end, and roughly turn the end face, inner hole and outer circle of the forging barrel 200 to meet the rough processing drawing before heat treatment, and then clamp and rough turn the other end of the forging barrel 200 according to the above operations. After rough turning, ensure that 3mm machining allowances are left on each side of the forging barrel 200 to ensure that the subsequent processing requirements can still be met after deformation and oxide scale shedding after subsequent heat treatment.

[0047] Step 2: heat treat the forging barrel 200 after rough turning; the heat treatment method of the forging barrel 200 is selected according to the material properties of the arc surface valve seat 100. For example, if the material of the arc surface valve seat 100 in the present invention is 17-4PH / H1150+TCC, then the forging barrel 200 is heat treated by solution treatment and aging hardening treatment.

[0048] Step 3, semi-finishing turning of the forging barrel 200; during semi-finishing turning, first position and clamp one end of the heat-treated forging barrel 200 by the chuck of the CNC lathe, then level the outer circle and end face of the other end of the forging barrel 200, and process the end face, outer circle and inner hole chamfers of this end to meet the processing drawing before wire cutting; then process the other end of the forging barrel 200 according to the above operations, so that the size of the other end of the forging barrel 200 also meets the processing drawing before wire cutting; except for the inner diameter and outer diameter of the forging barrel 200, which have a single-side grinding allowance of 1mm, the other dimensions of the semi-finishing forged barrel 200 are completely consistent with the finished product design dimensions of the curved valve seat 100.

[0049] Step 4: Mill out the reference line, groove and window on the forging barrel 200; when milling the reference line, on the four-axis vertical milling machining center, use the chuck to fix the inner hole at one end of the forging barrel 200, use the tailstock umbrella-shaped top to support the inner hole cone surface at the other end of the forging barrel 200, align the vertical milling spindle and the central axis of the forging barrel 200, and use a 60° chamfered milling cutter to mill out a reference line with a depth of 0.5mm at any position of the outer circle of the forging barrel 200 in the direction of the generatrix to ensure the first cutting position during subsequent wire cutting. The datum serves as the starting position of the programming datum for subsequent milling processing; when milling the window, the clamping of the forging tube 200 remains unchanged, and the datum line is used as the starting point for programming the CNC milling machine to mill out three windows in sequence; when milling the spring groove in the groove, the clamping of the forging tube 200 remains unchanged, and the datum line is used as the starting point for programming the CNC milling machine to mill out six spring grooves in sequence; when milling the O-ring groove in the groove, the clamping of the forging tube 200 remains unchanged, and the datum line is used as the starting point for programming the CNC milling machine to mill out three O-ring grooves around the window in sequence.

[0050] Step 5, milling pin holes on the forging barrel 200; fix the forging barrel 200 on the workbench of the vertical milling machining center by a three-jaw chuck, position and clamp the end face and outer circle of one end of the forging barrel 200, use the vertical milling spindle to align the outer circle of the forging barrel 200, and use the reference line processed in step 4 as the starting point for programming to process the end face pin hole of the other end of the forging barrel 200; then complete the pin hole processing of the two end faces of the forging barrel 200 according to the above operations.

[0051] Step six, wire cutting the forging barrel 200; place the end face of the forging barrel 200 on the plane guide rail of the wire cutting machine, clamp it through the pull rod and the pressure plate, straighten the outer circle generatrix of the forging barrel 200, use the reference line processed in step four as the first wire cutting position, and decompose the forging barrel 200 into three semi-finished products of the arc valve seat 100.

[0052] Step seven, artificially age the semi-finished curved valve seat 100 obtained by wire cutting; since the forging tube 200 continuously releases stress during the process of wire cutting, the curved valve seat 100 will be deformed after the wire cutting is completed. In order to enable the curved valve seat 100 to completely release the wire cutting stress to prevent the continued deformation, the present invention performs thermal aging treatment on the curved valve seat 100 obtained by wire cutting of the forging tube 200, heats the curved valve seat 100 to 200-250°C and keeps it warm for at least 4 hours, and then cools it in the furnace or takes it out and cools it to room temperature in the air; by artificially ageing the curved valve seat 100 obtained by wire cutting, the stress release caused by wire cutting can be effectively eliminated, the product size can be stabilized, and the deformation of the curved valve seat 100 caused by residual stress in subsequent processing can be avoided.

[0053] Step 8: Roughly grind the outer circumference of the arc surface valve seat 100. In the present invention, when rough grinding the outer circumference of the arc surface valve seat 100, the outer circumference grinding tool 300 is used to position and clamp the arc surface valve seat 100. The outer circumference grinding tool 300 is as follows: Figures 3 to 5As shown, it is composed of a rotary shaft 310 and a clamp 320; specifically, the rotary shaft 310 is composed of a positioning sleeve 311, a first outer end cover 312 and a second outer end cover 313. The positioning sleeve 311 is a cylindrical structure whose outer circle is adapted to the inner arc surface of the arc valve seat 100. The first outer end cover 312 and the second outer end cover 313 are end cover structures coaxially arranged with the positioning sleeve 311. The first outer end cover 312 and the second outer end cover 313 are respectively detachably connected and fixed at both ends of the positioning sleeve 311 by screws. The outer diameter is larger than the outer diameter of the positioning sleeve 311; a plurality of toggle studs 314 are fixed on the outer end face of the first outer end cover 312, and the toggle studs are used to connect with the spindle of the external cylindrical grinder; a top hole is provided at the center position of the outer end face of the first outer end cover 312 and the second outer end cover 313, and the top hole is used to cooperate with the top of the spindle of the external cylindrical grinder; the clamp 320 is composed of two semicircular retaining rings detachably connected by bolts and nuts, and the number of the clamp 320 is two groups, and the arc valve seat 100 can be clamped on the positioning sleeve 311 of the rotating shaft 310 through the clamp 320. When the outer circle grinding tool 300 is used to perform rough outer circle grinding on the arc surface valve seat 100, the arc surface valve seat 100 is first fixed on the outer circle grinding tool 300, and the two arc surface valve seats 100 are respectively abutted on the upper and lower outer surfaces of the positioning sleeve 311, and the two arc surface valve seats 100 are symmetrical with the central axis of the positioning sleeve 311 as a reference, and the first outer end cover 312 and the second outer end cover 313 are respectively abutted against the two ends of the arc surface valve seat 100 to form an axial limit for the arc surface valve seat 100, and the arc surface valve seat 100 and the two outer end covers are also provided with positioning pins and positioning pins. The positioning is achieved by a positioning structure composed of holes. The positioning pins are generally fixedly arranged on the end faces of the two outer end covers facing the arc valve seat 100. The symmetrical arrangement of the arc valve seat 100 is ensured by the positioning structure to meet the roundness tolerance of grinding and avoid the appearance of an ellipse. Then, the two sets of clamps 320 are respectively mounted on the two ends of the arc valve seat 100, and the two semicircular retaining rings of the clamps 320 are locked by bolts so that the two sets of clamps 320 clamp the two ends of the arc valve seat 100 on the positioning sleeve 311, thereby fixing the arc valve seat 100 on the outer circle grinding tooling 300.After the arc surface valve seat 100 is fixed, the outer cylindrical grinding tool 300 is hoisted to the outer cylindrical grinder, and the toggle stud 314 on the rotary shaft 310 is connected to the main shaft of the outer cylindrical grinder. The fixed top of the main shaft of the outer cylindrical grinder bears against the top hole at the center of the first outer end cover 312, and the movable top of the main shaft of the outer cylindrical grinder bears against the top hole at the center of the second outer end cover 313. The main shaft of the outer cylindrical grinder drives the rotary shaft 310 to rotate through the toggle stud 314, and the grinding wheel of the outer cylindrical grinder grinds the outer circle of the arc surface valve seat 100; the grinding parts include the outer circle middle part and the outer circle of the arc surface valve seat 100. end; when grinding the middle of the outer circle, two sets of clamps 320 are fixed at the end positions of both ends of the arc surface valve seat 100, so that the middle part of the arc surface valve seat 100 is exposed for grinding; when grinding the two ends of the outer circle, the two sets of clamps 320 are moved close to the middle of the arc surface valve seat 100, so that the two ends of the arc surface valve seat 100 are exposed for grinding; the arc surface valve seat 100 is clamped twice by the clamps 320 to achieve the overall grinding of the outer circle of the arc surface valve seat 100, and the actual height difference of the cutting marks is less than 0.02mm, and it can be directly polished with gauze, which does not affect the use of the outer circle of the arc surface valve seat 100 as a positioning reference. After grinding, the size of the unground parts at both ends of the arc surface valve seat 100 meets the requirements of the processing technology before spraying, and then the two sets of clamps 320 are removed, and the arc surface valve seat 100 is tilted down from the outer circle grinding tool 300. By first grinding the outer circle of the arc surface valve seat 100 , the same tooling and a unified outer circle reference can be used in the subsequent rough grinding and fine grinding of the inner hole, thereby reducing the grinding process and shortening the overall processing cycle of the arc surface valve seat 100 .

[0054] Step 9: Roughly grind the inner hole of the arc surface valve seat 100. In the present invention, the inner hole grinding tool 400 is used to position and clamp the arc surface valve seat 100 when the inner hole of the arc surface valve seat 100 is roughly ground. Figures 6 to 8 As shown, it includes a positioning sleeve 410, a third outer end cover 420, a fourth outer end cover 430, a support block 440 and a tensioning assembly; the positioning sleeve 410 is a cylindrical structure whose inner circle matches the outer arc surface of the arc valve seat 100, and the third outer end cover 420 and the fourth outer end cover 430 are end cover structures coaxially arranged with the positioning sleeve 410. The third outer end cover 420 and the fourth outer end cover 430 are respectively detachably connected and fixed at both ends of the positioning sleeve 410 by screws. Fig. 9 As shown, the support block 440 is an arc-shaped plate structure, and the support block 440 has an arc surface that matches the inner surface of the arc valve seat 100, and a limiting groove is provided on the other side of the support block 440 relative to the arc surface. Figures 6 to 8 , Fig.10As shown, the tensioning assembly includes two wedge blocks 450, which are arc-shaped blocks with beveled edges. The wedge blocks 450 are formed by tube processing and then wire cutting. The two wedge blocks 450 are inserted between two arc-shaped valve seats 100 to form a limit fit, and the arc surface of the wedge block 450 is adapted to the inner surface of the positioning sleeve 410. In order to avoid self-locking of the wedge block 450, the angle inclination of the wedge block 450 can be limited to be greater than the friction angle of the material. When the inner hole grinding tool 400 is used to roughly grind the inner hole of the arc surface valve seat 100, first fix the fourth outer end cover 430 to the corresponding end of the positioning sleeve 410, and then put the two arc surface valve seats 100 into the positioning sleeve 410, so that the outer arc surface of the arc surface valve seat 100 is in contact with the inner arc surface of the positioning sleeve 410; the arc surface valve seat 100 is positioned by a positioning structure composed of positioning pins and positioning holes, so that the arc surface valve seat 100 is symmetrically arranged in the positioning sleeve 410 with the central axis of the positioning sleeve 410 as a reference. The positioning pins are generally fixedly arranged on the end faces of the two outer end covers facing the arc surface valve seat 100, and the positioning pins are generally fixedly arranged on the end faces of the two outer end covers facing the arc surface valve seat 100. The positioning structure of the arc valve seat 100 ensures the symmetrical arrangement of the two arc valve seats 100, thereby improving the shape and position tolerance value of the grinding process; then the outer arc surfaces of the two support blocks 440 are respectively abutted against the inner arc surfaces of the two arc valve seats 100, and the jack 460 is inserted between the two support blocks 440, and the limiting grooves on the support blocks 440 form a limiting match with the jack, and the two support blocks 440 are tightened by the jack 460; then the two sets of tensioning components are respectively inserted into the gap between the two arc valve seats 100, and when inserting the tensioning components, one of the wedge blocks 450 is inserted first, so that The outer arc surface of the wedge block 450 is in contact with the inner arc surface of the positioning sleeve 410, and then another wedge block 450 is inserted, so that the outer arc surface of the wedge block 450 is also in contact with the inner arc surface of the positioning sleeve 410. The end surface of the wedge block 450 is hit with a rubber hammer. The tensioning assembly uses the wedge block clamping principle and the interaction of the two wedge blocks 450 in the same tensioning assembly to completely fix the arc valve seat 100 that needs to be ground. All degrees of freedom of the two wedge blocks 450 and the arc valve seat 100 are constrained and cannot be displaced, ensuring that the arc valve seat 100 can be fixed after the jack 460 is removed. It can fully withstand the cutting force in the grinding process without displacement in any direction; finally, the jack 460 and the support block 440 are removed, and the third outer end cover 420 is fixedly connected to the corresponding end of the positioning sleeve 410, and the third outer end cover 420 and the fourth outer end cover 430 are used to form axial limits on the two ends of the arc valve seat 100 and the wedge block 450; the third outer end cover 420 and the fourth outer end cover 430 can not only avoid the vibration of the wedge block 450 and the arc valve seat 100 under the action of external force when the tooling is hoisted as a whole, but also eliminate the loose position caused by the influence of cutting force during grinding.After fixing the arc valve seat 100 on the inner hole grinding tooling 400, hoist the assembled inner hole grinding tooling 400 onto the internal cylindrical grinder, clamp the outer circle and end face of the inner hole grinding tooling 400 by the three-jaw chuck of the internal cylindrical grinder spindle, calibrate the outer circle of the inner hole grinding tooling 400, and grind the inner arc surface of the arc valve seat 100.

[0055] Step 10: Chamfer the flow channel window of the arc surface valve seat 100; chamfer the flow channel window on the arc surface valve seat 100 by using an angle grinder and a semicircular file for manual grinding, so that the flow channel window forms a transition radius from R2 to R3, and then polishes it with a cloth grinding wheel. By chamfering the flow channel window of the arc surface valve seat 100, it is possible to effectively prevent the intersection line of the inner and outer orifices of the flow channel from adsorbing or accumulating alloy powder when spraying the alloy.

[0056] Step 11: Perform nondestructive testing (PT) on the inner surface of the arc of the arc valve seat 100 . It is required that the inner surface of the arc of the arc valve seat 100 does not have any defects such as slag inclusions and cracks.

[0057] Step 12: Spray alloy on the arc surface valve seat 100; use HV0 supersonic spraying of tungsten carbide coating, which has the advantages of high hardness, high bonding strength and good wear resistance; perform spraying according to the welding process to ensure that the processing allowance of the spray layer is 0.3mm on one side; keep the temperature of the arc surface valve seat 100 less than 200°C during the spraying process, which can effectively eliminate the problem of deformation of the arc surface valve seat 100 caused by thermal stress again.

[0058] Step 13, fine grinding the inner hole of the arc surface valve seat 100; the inner hole fine grinding process adopts the inner hole grinding tool 400 in step nine, and the arc surface valve seat 100 is fixed to the inner hole grinding tool 400 by the same clamping method, and the inner hole of the arc surface valve seat 100 after alloy spraying is ground by the same grinding method as in step nine until it meets the design size, and then polished with a wool wheel and polishing paste to make the surface roughness of the arc surface valve seat 100 reach below Ra0.2, which can meet the sealing requirements.

[0059] Step 14, fine grinding the outer circle of the arc surface valve seat 100; the outer circle fine grinding adopts the outer circle grinding tool 300 in step eight, and the arc surface valve seat 100 is fixed on the outer circle grinding tool 300 by the same clamping method, and the outer circle of the arc surface valve seat 100 sprayed with alloy is ground by the same grinding method as in step eight; in this step, since the inner hole size of the arc surface valve seat 100 becomes larger after fine grinding of the inner hole of the arc surface valve seat 100 in the previous process, it is necessary to replace the rotating shaft 310 used for fine grinding to ensure the uniformity of the inner hole positioning size and complete the fine grinding of the outer circle of the arc surface valve seat 100.

[0060] Step 15: Perform flaw detection on the sprayed surface of the arc valve seat 100; perform nondestructive flaw detection (PT) on the arc inner surface of the arc valve seat 100, requiring that the arc inner surface of the arc valve seat 100 does not have any defects such as slag inclusions and cracks.

[0061] Step 16: Perform quality inspection on the finished size of the arc surface valve seat 100; the quality inspection methods include but are not limited to: the first method, using three-coordinate design drawings for inspection; the second method, using a plug to inspect the arc surface valve seat 100, placing the inner circular surface of the arc surface valve seat 100 against the outer circular surface of the plug, and using stainless steel feeler gauges of different sizes to inspect the gap between the arc surface valve seat 100 and the plug. The size specifications of the stainless steel feeler gauge are 0.005mm, 0.01mm and 0.015mm. If the gap is detected to be ≤0.15mm, the size of the finished arc surface valve seat 100 is determined to be qualified.

Claims

1. A method for processing a curved valve seat of a slurry plug valve, characterized in that: In the processing of the arc surface valve seat (100), the forging tube material (200) is subjected to wire cutting to obtain a semi-finished product of the arc surface valve seat (100), and then artificial aging treatment is performed.

2. The method for processing the arc surface valve seat of the slurry plug valve according to claim 1, characterized in that: Follow these steps in order: Step 1: Rough turning the forging tube material (200) so that machining allowances are left on each side of the forging tube material (200); Step 2: heat treating the forging tube material (200) by using solid solution treatment and aging hardening treatment; Step 3, semi-finish turning the forging tube material (200); Step 4: milling a reference line, a groove and a window on the forging tube material (200); Step 5: milling pin holes on the forging barrel (200); Step 6: Perform wire cutting on the forged tube material (200) to decompose the forged tube material (200) into three semi-finished products of the arc surface valve seat (100); Step 7: Performing artificial aging treatment on the arc surface valve seat (100), heating the arc surface valve seat (100) to 200-250° C. and keeping the temperature for at least 4 hours, and then cooling it to room temperature; Step 8: using the outer circle grinding tool (300) to roughly grind the outer circle of the arc surface valve seat (100); Step nine, using the inner hole grinding tool (400) to roughly grind the inner hole of the arc surface valve seat (100); Step 10, chamfering the flow channel window of the arc surface valve seat (100); Step 11: Perform flaw detection on the arc inner surface of the arc valve seat (100); Step 12: spraying alloy onto the arc surface valve seat (100); Step 13: using the inner hole grinding tool (400) in step 9 to finely grind the inner hole of the arc surface valve seat (100); Step 14: using the outer circle grinding tool (300) in step 8 to finely grind the outer circle of the arc surface valve seat (100); Step 15: Perform flaw detection on the sprayed surface of the arc valve seat (100); Step 16: Perform quality inspection on the finished product size of the arc surface valve seat (100).

3. The method for processing the arc surface valve seat of the slurry plug valve according to claim 1, characterized in that: In the step 1, after rough turning, a machining allowance of 3 mm is left on each side of the forging tube material (200).

4. The method for processing the arc surface valve seat of the slurry plug valve according to claim 1, characterized in that: In the step three, the forging barrel (200) is semi-finished turned so that the outer diameter and the inner diameter of the forging barrel (200) each have a single-side grinding allowance of 1 mm, so that the remaining dimensions of the forging barrel (200) meet the design dimensions of the arc valve seat (100).

5. The method for processing the arc surface valve seat of a slurry plug valve according to claim 1, characterized in that: In the steps 8 and 14, the external cylindrical grinding tool (300) used comprises a rotary shaft (310) and two sets of clamps (320); the rotary shaft (310) is composed of a positioning sleeve (311), a first external end cover (312) and a second external end cover (313); the first external end cover (312) and the second external end cover (313) are coaxially arranged with the positioning sleeve (311) and are respectively detachably connected to the two ends of the positioning sleeve (311); a toggle stud (314) is fixed on the external end surface of the first external end cover (312); and a top hole is provided at the center of the external end surfaces of the first external end cover (312) and the second external end cover (313); the clamp (320) is composed of two semicircular clamps that are detachably connected; When assembled with the arc-surface valve seat (100), the two arc-surface valve seats (100) are placed against the outer surface of the positioning sleeve (311), and the two arc-surface valve seats (100) are symmetrical with respect to the central axis of the positioning sleeve (311). The arc-surface valve seat (100) forms a positioning fit with the first outer end cover (312) and the second outer end cover (313) through a positioning structure composed of a positioning pin and a positioning hole. The two ends of the arc-surface valve seat (100) respectively form an axial limit fit with the first outer end cover (312) and the second outer end cover (313). The two sets of clamps (320) are respectively mounted on the two ends of the arc-surface valve seat (100) and the arc-surface valve seat (100) is clamped on the positioning sleeve (311).

6. The method for processing the arc surface valve seat of a slurry plug valve according to claim 1, characterized in that: In the above-mentioned steps 9 and 13, the inner hole grinding tool (400) used comprises a positioning sleeve (410), a third outer end cover (420), a fourth outer end cover (430), two support blocks (440) and two sets of tensioning components; the third outer end cover (420) and the fourth outer end cover (430) are coaxially arranged with the positioning sleeve (410) and are detachably connected to the two ends of the positioning sleeve (410); the support block (440) has an arc surface that matches the inner surface of the arc surface valve seat (100), and a limiting groove is provided on the other side of the support block (440) relative to the arc surface; when assembling with the arc surface valve seat (100), the fourth outer end cover (430) is fixed on the positioning sleeve (410), and the two arc surface valve seats (100) are assembled with the positioning sleeve (410). 0), and the two arc-surface valve seats (100) are symmetrical with respect to the central axis of the positioning sleeve (410); the arc-surface valve seats (100) are positioned and matched with the fourth outer end cover (430) through a positioning structure composed of positioning pins and positioning holes; the two support blocks (440) are respectively positioned and matched with the inner surfaces of the two arc-surface valve seats (100); the two support blocks (440) are pressed against the corresponding arc-surface valve seats (100) using a jack (460); the two sets of tensioning components are respectively inserted into the gap between the two arc-surface valve seats (100) to form a limiting fit with the arc-surface valve seats (100); after removing the jack (460) and the support block (440), the third outer end cover (420) is fixed on the positioning sleeve (410).

7. The method for processing the arc surface valve seat of the slurry plug valve according to claim 6, characterized in that: The tensioning assembly comprises two wedge blocks (450), which are arc-shaped blocks with beveled edges. The two wedge blocks (450) are inserted between two arc-surface valve seats (100) to form a limit fit; the arc surface of the wedge block (450) is adapted to the inner surface of the positioning sleeve (410).

8. The method for processing the arc surface valve seat of a slurry plug valve according to claim 1, characterized in that: In the step twelve, the alloy is sprayed with a tungsten carbide coating by HV0 supersonic spraying. During the spraying process, the temperature of the arc valve seat (100) is maintained at less than 200° C., and the processing allowance of the coating is 0.3 mm on a single side.

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