A machining method for a large nozzle ring seat high-precision inner hole multi-stage ring groove

Abstract

The application relates to the technical field of cutting technology, in particular to a machining method for a high-precision multi-stage ring groove of a large nozzle ring seat inner hole, which independently divides the multi-stage ring groove quantity of the large nozzle ring seat blank inner hole into a bottom groove unit, a left side unit and a right side unit; a semi-finishing allowance is confirmed, and the bottom groove unit, the left side unit and the right side unit are respectively semi-finished based on the allowance; the bottom groove unit, the left side unit and the right side unit after semi-finishing are successively finished to obtain a qualified large nozzle ring seat. The method divides the multi-stage ring groove of the large nozzle ring seat inner hole into three independent units of a bottom surface, a left side surface and a right side surface for turning, redefines the tool path in the turning process, unifies the new allowance compensation direction and the detection method, and realizes the precision control and high-efficiency machining of the groove surface size of each stage of the ring groove.

Description

Technical Field

[0001] This invention relates to the field of metal cutting technology, and in particular to a method for machining high-precision multi-stage annular grooves in the inner hole of a large nozzle ring seat. Background Technology

[0002] The multi-stage inner hole annular groove of the nozzle ring seat is matched with a multi-stage nozzle ring with blades during the assembly process. In order to ensure that the nozzle ring has sufficient positional accuracy after being assembled in the nozzle ring seat, high precision is required when machining the multi-stage inner hole annular groove of the nozzle ring seat. However, with the leapfrog increase in the power of expanders, the structural dimensions of components such as nozzle ring seats and nozzle rings have increased exponentially. Currently, the width and depth of each groove surface of the multi-stage annular groove of the nozzle ring seat of high-power expanders are two to three times or more than the traditional structural dimensions.

[0003] Traditional methods for machining multi-stage annular grooves in the inner bore of large nozzle ring seats, such as Figure 3 As shown, the worker turns a single-stage annular groove as a whole unit. The tool enters axially from both sides of the groove and turns to the bottom of the groove. Then, it enters normally and turns to the middle position of the bottom of the groove before retracting the tool. After completing the turning of the single-stage annular groove, the turning of the next stage annular groove is carried out. This process is repeated to complete the machining of the four-stage annular groove in the inner hole of the large nozzle ring seat. This machining method does not have problems such as insufficient rigidity of the tool itself or premature wear of the cutting edge, which may lead to unqualified side taper and dimensional machining when the depth and width of the multi-stage annular groove in the inner hole of the nozzle ring seat are small.

[0004] However, as the size of the nozzle ring seat structure increases dramatically, the depth and width of the multi-stage ring grooves increase exponentially. Traditional turning methods have problems in actual machining, such as the taper on the side of the deep groove and the difficulty in guaranteeing the dimensional tolerances. Summary of the Invention

[0005] The purpose of this invention is to provide a machining method for high-precision multi-stage annular grooves in the inner hole of a large nozzle ring seat, which aims to solve the problem that traditional turning methods for multi-stage annular grooves in the inner hole of large nozzle ring seats are difficult to guarantee dimensional tolerances.

[0006] To achieve the above objectives, the present invention provides a method for machining a high-precision multi-stage annular groove in the inner hole of a large nozzle ring seat, comprising the following steps:

[0007] The number of multi-level annular grooves in the inner hole of the large nozzle ring seat blank is divided into independent units to obtain the bottom groove unit, the left side unit and the right side unit;

[0008] Confirm the semi-finishing allowance, and perform semi-finishing machining on the bottom groove unit, the left side unit, and the right side unit based on the allowance;

[0009] The bottom groove unit, the left side unit and the right side unit after half-rough turning are successively finish turned to obtain qualified large nozzle ring seat.

[0010] The specific manner of successively finish turning the bottom groove unit, the left side unit and the right side unit after half-rough turning to obtain qualified large nozzle ring seat comprises:

[0011] Finish turning the bottom groove unit after half-rough turning;

[0012] Finish turning the left side unit after half-rough turning;

[0013] Finish turning the right side unit after half-rough turning.

[0014] The specific manner of finish turning the bottom groove unit after half-rough turning comprises:

[0015] Checking the wear condition of the tool blade edge after half-rough turning the remaining amount and judging whether to replace the tool based on the wear condition;

[0016] Confirming the sharpness and integrity of the tool blade edge and finish turning the bottom groove unit;

[0017] According to the design size, measuring the diameter of the bottom groove unit after finish turning and supplementing the tool until the diameter of the bottom groove unit corresponds to the design size.

[0018] The specific manner of finish turning the left side unit after half-rough turning comprises:

[0019] Detecting the wear condition of the tool blade edge and the left side after finish turning the bottom groove unit and judging whether to replace the tool based on the wear condition;

[0020] Confirming the sharpness and integrity of the tool blade edge and finish turning the left side unit;

[0021] According to the design size, measuring the position size of the left side unit after finish turning and supplementing the tool until the position size of the left side unit corresponds to the design size.

[0022] The specific manner of finish turning the right side unit after half-rough turning comprises:

[0023] Detecting the wear condition of the tool blade edge and the right side after finish turning the left side unit and judging whether to replace the tool based on the wear condition;

[0024] Confirming the sharpness and integrity of the tool blade edge and finish turning the right side unit;

[0025] According to the design size, measuring the position size of the right side unit after finish turning and supplementing the tool until the position size of the right side unit corresponds to the design size.

[0026] The machining method of the large nozzle ring seat high-precision inner hole multi-stage ring groove of the present application independently divides the number of multi-stage ring grooves of the inner hole of the large nozzle ring seat blank, obtains a bottom groove unit, a left side unit and a right side unit, confirms the semi-finishing allowance, and semi-finishes the bottom groove unit, the left side unit and the right side unit based on the allowance; the bottom groove unit, the left side unit and the right side unit after semi-finishing are finished in turn to obtain a qualified large nozzle ring seat. The method divides the large nozzle ring seat inner hole multi-stage ring groove into three independent units for turning, redefines the tool path during turning, unifies the new allowance compensation direction and detection method, realizes the precision control and high efficiency processing of the size of each ring groove surface, divides the nozzle ring seat multi-stage ring groove into three independent units according to the tool stress and wear during turning, effectively avoids the risk of affecting the processing quality of the ring groove side surface due to the early wear of the tool in the traditional turning processing of the multi-stage ring groove, greatly improves the one-time processing qualification rate of the part, and the worker only needs to compensate the tool in the same direction once during the processing of multiple surfaces in the independent unit to ensure that the multiple surfaces of the ring groove meet the design high-precision size tolerance requirement, greatly reduces the labor intensity of the worker, effectively reduces the calculation and operation time of the compensation tool, and improves the part processing efficiency. Taking a five-stage ring groove as an example, the five-stage ring groove involves five left side surfaces, five right side surfaces and five bottom surfaces in total. The worker only needs to turn the first-stage ring groove side surface to the position size tolerance during the final forming turning of the ring groove left side surface, and can effectively judge the processing condition of all ring groove left side surfaces by measuring whether the size tolerance of the fifth-stage ring groove left side surface after final turning meets the design requirement. When the position size tolerance of the fifth-stage ring groove meets the design requirement, it can be determined that the remaining ring groove left side surfaces also meet the design size requirement. At the same time, by comparing the size tolerance of the first and last left side surfaces, the wear condition of the tool edge can also be quickly judged. The worker can determine the surface that needs to be measured in the independent unit according to the processing condition of the final-stage ring groove left side surface, thereby realizing the efficient processing of the part, and solving the problem that the traditional machining method of the large nozzle ring seat inner hole multi-stage ring groove cannot guarantee the tolerance size. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any inventive labor.

[0028] Figure 1 is a schematic view of a large nozzle ring seat structure.

[0029] Figure 2 is a high-precision inner hole multi-stage ring groove structure schematic diagram provided by the present application.

[0030] Figure 3 is a traditional multi-stage ring groove machining method schematic diagram.

[0031] Figure 4 is a tool elongation schematic diagram.

[0032] Figure 5 is a side turning tool force schematic diagram.

[0033] Figure 6 is a groove bottom turning tool force schematic diagram.

[0034] Figure 7 is a schematic diagram of the division and feed method of the independent three-unit.

[0035] Figure 8 is a semi-finishing feed path and sequence schematic diagram.

[0036] Figure 9 is a large nozzle ring seat high-precision inner hole multi-stage ring groove machining method flowchart provided by the present application.

[0037] Figure 10 is a specific way flowchart of sequentially finishing the bottom groove unit, the left side unit and the right side unit after semi-finishing to obtain a qualified large nozzle ring seat. DETAILED DESCRIPTION

[0038] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numbers represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0039] The single-side depth of the existing large nozzle ring seat inner hole multi-stage ring groove is basically greater than 30 mm, and the groove cutter satisfying the turning of such a ring groove is usually a special customized cutter. In order to avoid the interference between the cutter body and the inner hole of the part, the elongation of the cutting part of the blade must be greater than 30 mm, and the elongation position is as shown in Figure 4 Compared with the elongation of the general conventional inner hole slotting cutter of less than 10 mm, the elongation of more than 30 mm means that the cutting part cutter structure itself lacks rigidity, and this characteristic is particularly obvious in the machining of the deep groove bottom of the multi-stage ring groove. The forces of the cutter in side and bottom turning are respectively as shown in Figure 5 and Figure 6As shown in the two figures, the biggest difference between the side and bottom turning of the cutter is the direction of the main and auxiliary cutting forces during the movement of the cutter. The main cutting force is the axial direction of the cutter during side turning, and the rigidity of the cutter is sufficient during machining. However, the direction of the main cutting force of the cutter during bottom turning is the normal direction of the cutter shaft. Due to the excessive elongation of the cutter, the rigidity of the cutter itself is insufficient, and there is inevitable slight vibration during actual groove bottom turning. The existence of the vibration causes the intensification of the wear of the cutting edges at the two side corners of the cutter during the cutting process. The forming quality of the side surface during actual turning is closely related to the sharpness and integrity of the cutting edges involved in the cutting. When the cutting edges involved in the side cutting appear slight wear and passivation, the normal auxiliary cutting force of the cutter during side turning increases significantly. The increase of the normal force causes the deformation of the cutter and the occurrence of the cutter relief phenomenon, and the machined side surface appears taper. In order to solve the problem that the machining method of the multi-stage ring groove of the inner hole of the traditional large nozzle ring seat cannot guarantee the tolerance size, the following embodiments are provided for reference.

[0040] Please refer to Figures 1 to 10 The present application provides a machining method for a large nozzle ring seat high-precision inner hole multi-stage ring groove, comprising the following steps:

[0041] S1 independently divides the number of multi-stage ring grooves of the inner hole of the large nozzle ring seat blank into units to obtain a bottom groove unit, a left side unit and a right side unit;

[0042] Specifically, the number of multi-stage ring grooves of the inner hole of the large nozzle ring seat to be machined is divided into independent units, the objects and quantities of the machined surfaces in each independent unit are determined, and the machining method of each independent unit is determined according to the objects and quantities of the machined surfaces in each independent unit. Figure 2 Taking the four-stage ring groove of the inner hole of the large nozzle ring seat as an example, before machining, we divide it into a groove bottom, a left side and a right side three independent units, and the machining objects and quantities of each unit are as follows: the groove bottom unit includes the groove bottom of the first, second, third and fourth ring grooves, a total of four surfaces, and the specific positions are shown in Figure 7 1-1, 1-2, 1-3, 1-4 numbered areas in FIG. 1. The left side unit includes the left side of the first, second, third and fourth ring grooves, a total of four surfaces, and the specific positions are shown in Figure 7 2-1, 2-2, 2-3, 2-4 numbered areas in FIG. 2. The right side unit includes the right side of the first, second, third and fourth ring grooves, a total of four surfaces, and the specific positions are shown in Figure 7The method divides the multi-stage ring groove of the nozzle ring seat into three independent units according to the force and wear of the cutter in the turning process, effectively avoids the risk that the early wear of the cutter in the traditional turning process affects the machining quality of the side surface and the bottom surface of the multi-stage ring groove, and greatly improves the one-time machining qualified rate of the part.

[0043] S2 confirms the semi-finishing allowance, and semi-finishes the bottom groove unit, the left side unit and the right side unit respectively based on the allowance;

[0044] Specifically, the conventional allowance of the multi-stage ring groove side surface and the bottom surface of the part before machining is 1-1.5 mm, the finishing allowance of the bottom groove unit of the multi-stage ring groove is controlled to be 0.05-0.1 mm during the semi-finishing process, and the finishing allowance of the left side unit and the right side unit is controlled to be 0.1-0.2 mm. The smaller finishing allowance can greatly reduce the force of the cutter during the turning process, ensure that the cutter has sufficient rigidity, reduce the vibration amplitude of the cutter, prolong the service life of the cutter, and make the final turning surface meet the design requirements. The further reduction of the bottom finishing allowance compared with the side surface allowance can effectively reduce the normal force of the cutter when the cutter is cutting in the bottom unit, control the vibration of the cutter, and ensure that the bottom surface of the final turning is smooth and free of vibration marks. According to the set bottom and side surface allowance, the semi-finishing of the bottom and side surface allowance of each groove of the multi-stage ring groove is completed by using the axial feed method. The specific cutting method is shown in the figure. Figure 8 The bottom and side surface allowance thickness of the semi-finished part is reduced from the original 1.5 mm to less than 0.2 mm, wherein the bottom is controlled to be 0.05-0.1 mm, and the left and right side allowances are controlled to be 0.1-0.2 mm.

[0045] S3 finishes the bottom groove unit, the left side unit and the right side unit in sequence after semi-finishing, and obtains a qualified large nozzle ring seat.

[0046] Specifically,

[0047] S31 finishes the bottom groove unit after semi-finishing;

[0048] Specifically,

[0049] S311 checks the wear of the cutter edge after semi-finishing the allowance, and judges whether to replace the cutter based on the wear;

[0050] Specifically, the wear of the cutter edge after semi-finishing is checked. When it is found that there is a small amount of wear on the side surface and the bottom edge of the cutter, a new blade should be replaced or the necessary grinding should be performed on the worn edge.

[0051] S312 confirms the sharpness and integrity of the tool edge, and finishes the bottom groove unit;

[0052] Specifically, after ensuring the sharpness and integrity of the tool edge, the bottom groove unit is finished according to the tool feed path of 1-1. Figure 7 The worker needs to measure the diameter of the groove bottom after completing the machining of 1-1, and make necessary tool compensation according to the actual rough thickness measured, so as to control the diameter of the groove bottom machined by 1-1 to be within the design size tolerance upper limit. When the diameter of the groove bottom machined by 1-1 reaches the size upper limit, the final tool compensation amount is recorded. The subsequent 1-2, 1-3, and 1-4 ring groove bottom machining is completed in turn with the final tool compensation amount. When the groove bottom is turned, the tool advances and retreats from the side, and the distance between the tool and the side is controlled to be between 0.5-1mm.

[0053] S313 measures the diameter of the bottom groove unit after finishing, and compensates the tool until the diameter of the bottom groove unit corresponds to the design size.

[0054] Specifically, the diameter of the 1-4 ring groove bottom is measured. When the diameter of the groove bottom is greater than the design size lower limit, the finishing of the groove bottom is completed. At this time, all the machined ring groove bottoms meet the design size tolerance requirements. When the worker has no actual data on the tool edge working life during the first machining process, the worker needs to observe the tool side and bottom edge after the tool completes the machining of a single ring groove bottom. When the tool edge is found to have obvious damage and dullness, the number N of machined surfaces is recorded, and the machining is terminated. After the machining is terminated, a new blade is replaced or the edge is ground as necessary. The new blade or the ground tool continues to complete the machining of the subsequent ring groove bottom from the termination point when participating in cutting, and the machining operation steps are restarted according to the above step 2 process. After the new tool or the ground tool completes the machining of the first diameter measurement surface that reaches the size upper limit, the machining of the subsequent ring groove bottom is continued. When N is greater than 4, it means that the tool edge can complete the machining of all the ring groove bottom surfaces within the actual working life. When N is less than 4, it means that the tool edge is not enough to complete the one-time machining of all the ring groove bottom surfaces, and its wear resistance needs to be further improved.

[0055] S32 finishes the left side unit after semi-finishing;

[0056] Specifically,

[0057] S321 detects the wear of the tool edge and the left side after finishing the bottom groove unit, and determines whether to replace the tool based on the wear.

[0058] Specifically, the worker checks the wear of the left side and the bottom edge of the tool after the finishing machining of the groove bottom unit, and replaces the new blade or grinds the worn blade as necessary when finding that there is a trace of wear on the left side and the bottom edge of the tool.

[0059] S322 confirms the sharpness and integrity of the tool edge and finishes machining the left side unit.

[0060] Specifically, after ensuring the sharpness and integrity of the tool edge, the worker finishes machining according to the feed trajectory of 2-1 on the left side unit. Figure 7 The worker measures the position and size of the left side of the ring groove after finishing the machining of 2-1, and grinds the tool as necessary according to the actual machined left side position, grinds the tool to the size below the standard when the left side position and size of the ring groove are on the left side of the part, and records the final grinding amount after the measurement is qualified, and then finishes the machining of the left side of the subsequent 2-2, 2-3, and 2-4 ring grooves; grinds the tool to the size above the standard when the left side position and size of the ring groove are on the right side of the part, and records the final grinding amount after the measurement is qualified, and then finishes the machining of the left side of the subsequent 2-2, 2-3, and 2-4 ring grooves.

[0061] S323 measures the position and size of the left side unit after finishing machining according to the design size, and grinds the tool until the position and size of the left side unit correspond to the design size.

[0062] Specifically, the worker measures the position and size of the left side of the 2-4 ring groove, which should be smaller than the design size above the standard when the reference is on the left side, and the machining of the multi-stage ring groove left side unit is completed, and all the left side machining is qualified; the position and size of the 2-4 ring groove should be greater than the design size below the standard when the reference is on the right side, and the machining of the multi-stage ring groove left side unit is completed, and all the left side machining is qualified.

[0063] S33 finishes machining the right side unit after half-finishing machining.

[0064] Specifically,

[0065] S331 detects the wear of the tool edge and the right side after finishing machining the left side unit, and determines whether to replace the tool based on the wear;

[0066] Specifically, the worker checks whether there is wear on the right side and the bottom edge of the tool after finishing machining the left side unit, and replaces the new blade or grinds the worn blade as necessary when finding that there is a trace of wear on the right side and the bottom edge of the tool.

[0067] S332 confirms the sharpness and integrity of the tool edge and finishes machining the right side unit.

[0068] Specifically, after ensuring the blade edge is sharp and intact, proceed as follows: Figure 7 The tool path of unit 3-1 on the right is used for finishing. After completing the machining of 3-1, the worker needs to measure the position dimension of the right side of the annular groove using a dial indicator. Based on the actual measured position of the right side, necessary additional cutting is performed. When the position dimension reference of the right side of the annular groove is on the left side of the part, the right side of the annular groove 3-1 is machined to the upper dimension. After the measurement is qualified, the final additional cutting amount is recorded, and the machining of the right side of the annular grooves 3-2, 3-3, and 3-4 is completed in sequence. When the position dimension reference of the right side of the annular groove is on the right side of the part, the right side of the annular groove 3-1 is machined to the lower dimension. After the measurement is qualified, the final additional cutting amount is recorded, and the machining of the right side of the annular grooves 3-2, 3-3, and 3-4 is completed in sequence.

[0069] S333 measures the positional dimensions of the right-side unit after precision machining according to the design dimensions and then performs additional machining until the positional dimensions of the right-side unit correspond to the design dimensions.

[0070] Specifically, measure the position dimension of the right side of the machined 3-4 ring groove. If the reference is on the left, the position dimension of the right side of the 3-4 ring groove should be greater than the lower difference of the design dimension. At this time, the machining of the right side unit of the multi-level ring groove is completed, and all right side surfaces are qualified. If the reference is on the right, the position dimension of the right side of the 3-4 ring groove should be less than the upper difference of the design dimension. At this time, the machining of the right side unit of the multi-level ring groove is completed, and all right side surfaces are qualified.

[0071] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that implementing all or part of the above embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A method for processing a large nozzle ring seat high-precision inner hole multi-stage ring groove, characterized in that, The method comprises the following steps: independent unit division is performed on the number of multi-stage ring grooves in the inner hole of the large nozzle ring seat blank, to obtain a bottom groove unit, a left side unit and a right side unit; a semi-finishing allowance is confirmed, and the bottom groove unit, the left side unit and the right side unit are semi-finished based on the allowance respectively; the bottom groove unit, the left side unit and the right side unit after semi-finishing are finished in sequence to obtain a qualified large nozzle ring seat.

2. The method according to claim 1, wherein, the specific way of finishing the bottom groove unit after semi-finishing is: after checking the wear of the tool edge after semi-finishing, it is judged whether to replace the tool based on the wear; the sharpness and integrity of the tool edge are confirmed, and the bottom groove unit is finished; the diameter of the bottom groove unit after finishing is measured and the tool is adjusted according to the design size until the diameter of the bottom groove unit corresponds to the design size.

3. The method according to claim 1, wherein, the specific way of finishing the left side unit after semi-finishing is: after detecting the wear of the tool edge and the left side after finishing the bottom groove unit, it is judged whether to replace the tool based on the wear; the sharpness and integrity of the tool edge are confirmed, and the left side unit is finished; the position size of the left side unit after finishing is measured and the tool is adjusted according to the design size until the position size of the left side unit corresponds to the design size.

4. The method according to claim 1, wherein, the specific way of finishing the right side unit after semi-finishing is: after detecting the wear of the tool edge and the right side after finishing the left side unit, it is judged whether to replace the tool based on the wear; the sharpness and integrity of the tool edge are confirmed, and the right side unit is finished; the position size of the right side unit after finishing is measured and the tool is adjusted according to the design size until the position size of the right side unit corresponds to the design size.

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