CN-117862814-B - Method for machining internal cutting line in large-fillet variable-radius branch pipe

CN117862814BCN 117862814 BCN117862814 BCN 117862814BCN-117862814-B

Abstract

The invention discloses a processing method of an intersecting line in a large-fillet variable-radius branch pipe, which particularly relates to the technical field of machining, and comprises a first step of modeling, a second step of entering a processing module UG, adopting fixed contour milling, a third step of attaching the outer edge of a three-dimensional sample block with a corresponding intersecting line from the three-dimensional sample block 4, removing unprocessed intersecting line surplus materials in place in a grinding mode, designing a test template according to the drawing requirement, accurately scribing the intersecting line according to the angle position of the test template, and carrying out rechecking on the intersecting line area by using the test template to confirm that the drawing requirement is met. According to the invention, the linear control of the internal cutting line in the large-fillet variable-radius branch pipe is accurately finished through the combined machining of milling and three-dimensional sample block profiling grinding and grinding, and the inspection template is designed for the inspection of a finished product according to the drawing acceptance standard, so that the machining size is ensured to meet the drawing requirement.

Inventors

YANG TAO
ZHAO HUIYU
CHEN XUE
Shao Haizheng
LI TIE
YANG QI
TENG NA
LIU XIAONING

Assignees

中国船舶集团渤海造船有限公司

Dates

Publication Date: 20260508
Application Date: 20231215

Claims (8)

1. The internal cutting line processing method in the large-fillet variable-radius branch pipe adopts UG software for modeling, and uses a processing module for numerical control programming, and is characterized by comprising the following steps: firstly, modeling, namely, only processing radius-changing corners within a range of-110 DEG to 110 DEG in the inner hole of the integrated pipe connecting seat according to a large-corner radius-changing pipe connecting seat inner hole intersecting line finished product diagram, and finally determining a modeling pattern, wherein the corners adopt radius-changing edge corners, and corresponding radius values R127, R115.3, R93.2, R65, R40.9, R24.6 and R15.2 are input at 0 DEG (+ -15 DEG, +/-30 DEG, +/-45 DEG, +/-60 DEG, +/-75 DEG and+/-90 DEG; Step two, a processing module of UG is entered, a boring machine with a diameter phi of 110mm and a milling cutter disc with a connecting part diameter phi of 130mm and a cutting maximum outer diameter phi of 320mm are adopted for milling, standard milling cutters with three-high types of R335.25-315, 1721XL and 60-20L-R10 are selected, the standard milling cutters are directly connected to the end part of the boring shaft, collision protection of an inner hole of 10mm is arranged, meanwhile, a 10mm safe distance is reserved for preventing interference collision, the allowance in a range of the radius of an inner fillet approaching 85mm is processed, and the allowance of the root part of the inner fillet is left to be unprocessed; thirdly, bonding the outer edge of the three-dimensional sample block with the corresponding intersecting line from the middle sample block (4) of-15 degrees to 15 degrees, removing unprocessed intersecting line surplus materials in place by utilizing a grinding mode, bonding and grinding the three-dimensional sample block and the corresponding intersecting line area by utilizing a grinding finish polishing mode to ensure that the overlap ratio reaches more than 85 percent, and sequentially bonding the adjacent 15 degrees to 45 degrees left sample blocks (3) and-45 degrees to-15 degrees right sample blocks (5) on two sides of the initial sample block, 45 degrees to 75 degrees left sample blocks (2) and-75 degrees to-45 degrees right sample blocks (6), grinding the corresponding positions by utilizing the grinding finish polishing of the left sample blocks (1) and-75 degrees to-110 degrees right sample blocks (7), and finishing overall trimming and grinding of all the intersecting line by means of smooth transition; and fourthly, designing a test template according to the drawing requirements, precisely scribing the intersecting line according to the angle position of the test template, and rechecking the intersecting line area by using the test template to confirm that the drawing requirements are met.
2. The method for machining the inner cutting line in the large-fillet variable-radius branch pipe according to claim 1, wherein: in the second step, the effective cutting fillet radius of the milling cutter is calculated to be lower than 95mm according to the size of the selected milling cutter head, meanwhile, a 10mm safety distance is reserved for interference collision prevention, the limit of fillet radius machining is 85mm, the maximum fillet machining size is 127mm, and the root of the fillet is at least 42mm unprocessed.
3. The method for machining the inner cutting line in the large-fillet variable-radius branch pipe according to claim 1, wherein: In the third step, a linear curved surface of an internal cutting line in a finished branch pipe product is collected during modeling, the external surface of a blank is processed by milling, the rest is processed according to a drawing, in consideration of the integrity of the line, two sample blocks at the two sides are designed at an angle of 35 degrees, the rest is divided at an angle of 30 degrees, and the whole sample block is divided into 7 parts by linear cutting.
4. The method for machining the inner cutting line in the large-fillet variable-radius branch pipe according to claim 1, wherein: the three-dimensional sample block is made of stainless steel.
5. The method for machining the inner cutting line in the large-fillet variable-radius branch pipe according to claim 1, wherein: In the third step, the sample blocks of the sample blocks (4) in-15 degrees to 15 degrees divided by a rectangular coordinate system are attached to corresponding positions during grinding, linear surfaces which are subjected to milling and have surface roughness which does not meet the requirements of the drawing are compared, areas which are not subjected to milling are subjected to area marking, redundant materials are ground, and the surfaces are polished until the surface meets the roughness requirements of the drawing.
6. The method for machining the inner cutting line in the large-fillet variable-radius branch pipe according to claim 5, wherein the method comprises the following steps: On the basis, when the matching degree of the lapping reaches more than 85%, the polishing of the sample block area is completed, the adjacent sample blocks on two sides of the initial sample block are sequentially lapped on the corresponding parts, and finally, sharp corners and burrs are removed through body finish polishing, so that the transitional polishing of each area is completed, and the processing work of the intersecting lines is completed.
7. The method for machining the inner cutting line in the large-fillet variable-radius branch pipe according to claim 1, wherein: In the fourth step, the sheet template is designed according to the size of each part marked by the drawing for inspection, the whole template comprises all circular arc line types at corresponding positions, one side of the intersecting line is in transition with the straight inner hole, the other side of the intersecting line is in transition with the inner wall of the main pipe, the hyperbolic template is arranged on the side of the intersecting line, the positioning of the hyperbolic template cannot be realized, the straight edge section is reserved on the upper part of the template for being attached to the inner wall of the straight inner hole, marking lines are arranged at the midpoint positions of the circular arcs of the template except for the template with 90 degrees and 105 degrees of the circular arcs which are too small, and the circular arcs are ensured to be symmetrical according to the marking line types by taking the marking lines as references.
8. The method for machining the inner cutting line in the large-fillet variable-radius branch pipe according to claim 1, wherein: And in the fourth step, firstly scribing the whole internal intersecting line according to the angle position marked by the template, correctly clamping the template according to the corresponding position, and verifying that the size is qualified through the coincidence of the template line type at the corresponding position and the line type of the processed internal intersecting line.

Description

Method for machining internal cutting line in large-fillet variable-radius branch pipe Technical Field The invention relates to the technical field of machining, in particular to a method for machining an internal cutting line in a large-fillet variable-radius branch pipe. Background In the stage of installing and testing water, the pipeline of the primary pipeline and the loop pipeline are subjected to the influence of fluid mechanics to generate system vibration, so that great potential safety hazard is brought to the system operation, the problem can be fundamentally solved by processing an intersecting line with a gradually-transitional variable radius large fillet at one side of an inner hole due to the unreasonable structure of the intersecting line of the inner hole of the primary pipeline hot section B pipe integrated branch pipe after analysis, and the design is applied to other subsequent products; The diameter of the finished product of the inner hole is phi 366.520-3 mm, the depth of the hole is 420mm, a rectangular coordinate system is established when the pipe orifice of the integrated branch pipe extends along the axis of the inner hole, the positive direction of the X axis points to 0 DEG, in more than half of the circumferential range from 110 DEG to 0 DEG to-110 DEG in the clockwise direction, the size of a round angle to be processed of the intersecting part of the inner hole of the integrated pipe seat and the main pipe is gradually changed from 9.50-1.5 mm to 1270-1.5 mm to 9.50-1.5 mm, the radius of the inner corner of the circumference of the rest part is 9.50-1.5 mm, and the intersecting line of the rest inner holes is processed according to 9.50-1.5 mm before the intersecting line of the local large round angle and the radius of the inner hole is processed; the inner hole machining usually considers that a cutter bar is additionally arranged on a boring machine to be machined by matching a milling cutter, the effective machining fillet radius of the milling cutter is (cutter head diameter-cutter bar diameter)/2, the cutting stability and the surface precision of the milling cutter can be influenced by excessively long cutter bar, impact and vibration are generated to damage the boring machine, obviously, a large fillet of an intersecting line of the inner hole cannot be machined and formed at one time, the workpiece is used for nuclear power primary loop, repair welding is never allowed, a proper cutter is selected for the workpiece, a reasonable machining process is formulated, and the machining risks that the machining is not in place, local excessive cutting or the excessive fillet size can be avoided by adopting a three-dimensional template to assist accurate grinding are solved. Disclosure of Invention In order to overcome the above-mentioned drawbacks of the prior art, the present invention provides a method for processing an inner cutting line in a large-fillet variable-radius branch pipe, so as to solve the above-mentioned problems in the prior art. In order to achieve the above purpose, the present invention provides the following technical solutions: The internal cutting line processing method in the large-fillet variable-radius branch pipe adopts UG software for modeling, and uses a processing module for numerical control programming, and the processing method comprises the following steps: Firstly, modeling, namely only processing radius-changing corners within a range of-110 DEG to 110 DEG in the inner hole of the integrated pipe connecting seat according to a large-corner radius-changing pipe connecting seat inner hole intersecting line finished product diagram, and finally determining a modeling pattern (a model for processing), wherein the corners adopt radius-changing edge corners, and corresponding radius values R127, R115.3, R93.2, R65, R40.9, R24.6 and R15.2 are input at 0 DEG, +/-15 DEG, +/-30 DEG, +/-45 DEG, +/-60 DEG, +/-75 DEG and+/-90 DEG; Step two, a processing module of UG is entered, a boring machine with a diameter phi of 110mm and a milling cutter disc with a connecting part diameter phi of 130mm and a cutting maximum outer diameter phi of 320mm are adopted for milling, standard milling cutters with three-high types of R335.25-315, 1721XL and 60-20L-R10 are selected, the standard milling cutters are directly connected to the end part of the boring shaft, collision protection of an inner hole of 10mm is arranged, meanwhile, a 10mm safe distance is reserved for preventing interference collision, the allowance in a range of the radius of an inner fillet approaching 85mm is processed, and the allowance of the root part of the inner fillet is left to be unprocessed; Thirdly, attaching the outer edge of a three-dimensional sample block made of stainless steel to the corresponding internal intersecting line from the sample block in the range of-15 degrees to 15 degrees, removing unprocessed internal intersecting line excess materials in place by utilizing a gr