CN104731018A - Method for machining reheat steam extraction pipe facing head of steam turbine medium-pressure heat shield - Google Patents
Method for machining reheat steam extraction pipe facing head of steam turbine medium-pressure heat shield Download PDFInfo
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- CN104731018A CN104731018A CN201410853499.0A CN201410853499A CN104731018A CN 104731018 A CN104731018 A CN 104731018A CN 201410853499 A CN201410853499 A CN 201410853499A CN 104731018 A CN104731018 A CN 104731018A
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- China
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- machining
- heat shield
- steam turbine
- facing head
- pipe facing
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Classifications
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
- G05B19/404—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/34—Director, elements to supervisory
- G05B2219/34167—Coarse fine, macro microinterpolation, preprocessor
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/37—Measurements
- G05B2219/37584—Deformation of machined material
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/45—Nc applications
- G05B2219/45136—Turning, lathe
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- Engineering & Computer Science (AREA)
- Human Computer Interaction (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Turning (AREA)
Abstract
The invention relates to a method for machining a reheat steam extraction pipe facing head of a steam turbine medium-pressure heat shield, and belongs to steam turbine spare part machining methods. The problem that the size accuracy is hard to guarantee in an existing machining process is solved. The method comprises the steps that 1, machining is conducted according to a cutting depth of finish machining, relieving amounts from delta 1 to delta n are measured, a curve from C1 to Cn is machined to a straight line from B1 to Bn in theory, and a mirror curve from A1 to An is made; 2, processing and measuring are conducted according to the cutting depth of the finish machining for multiple times, an average value is calculated, a point set close to a theoretical line is obtained, two adjacent points from A1 to An are connected with each other to form straight line sections from A1A2 to A<n-1>A<n> , and a program describes the machining trace through the straight line sections to conduct machining.
Description
Technical field
The present invention relates to the reheated steam extraction steam pipe facing head job operation of pressing heat shield in a kind of steam turbine, belong to turbine component job operation.
Background technology
Press in facing head processing vapor turbine in the reheated steam extraction steam pipe process of heat shield and have a kind of cutter relieving phenomenon (to be exactly that the rear measurement size of processing is larger than the theoretical size that will process, namely firm finished surface of the work former track sky when various key element is constant slips once, workpiece also can descend bits) very large on size Control impact, control bad being easy to and make workpiece size overproof.
Make a concrete analysis of as follows: as depicted in figs. 1 and 2, pressing in steam turbine in reheated steam extraction steam pipe one end of heat shield and steam turbine presses heat shield main body to weld together, be equivalent to the pipe of a beam type, and tube wall is thinner, the cutting force F produced during machining state Tool in Cutting workpiece produces two points, a component f
cuttangentially produce shear action, another component f
footpathfor radial direction acts on workpiece, make produce deformation during work pieces process, deformation has two kinds of situations, a kind of is the elastic deformation of material, the depression that processing rear knife edge acts on workpiece can be rebounded, this deformation the Tool in Cutting degree of depth can not reach theory calls, make excircle dimension larger than theoretical value, another kind of deformation refers to the flexural deformation of reheated steam extraction steam pipe tube wall, thiner than polycrystalline substance at reheated steam extraction steam pipe top, support little, the top of reheated steam extraction steam pipe is just large than deformation of bottom, the result produced makes processing reheated steam extraction steam pipe top cutting depth fewer than bottom cutting depth.These two kinds of shape controls are bad, add and are just difficult to man-hour ensure dimensional accuracy.
Summary of the invention
The object of this invention is to provide the reheated steam extraction steam pipe facing head job operation of pressing heat shield in a kind of steam turbine, be just difficult to ensure the problem of dimensional accuracy man-hour to solve existing adding.
The present invention solves the problems of the technologies described above the technical scheme taked to be: described method comprises step one, roughing: process by accurately machined cutting depth, workpiece to be added chooses n B point along highly equidistant, by B1, B2, B3 ... relieving amount Δ 1, Δ 2 are measured in Bn pointwise ... Δ n, by curve C 1-Cn, by theoretical processing linear B1-Bn, be a mirror curve A1-An, measure B1 by per-spot way, B2, B3 ... Bn point place relieving amount Δ 1, Δ 2 ... Δ n;
Step 2, calculating: to be averaged again by accurately machined cutting depth in-process measurement by several times and draw with close to theoretical relieving amount Δ 1, Δ 2 ... Δ n, obtain a point set close to Molded Line, calculate A1 again, A2, A3 ... the position of An point, by A1, A2, A3 ... adjacent 2 of An is in turn connected into straight-line segment A1A2, A2A3 ... A
n-1a
n, go out machining locus by this sets of line segments program description and process.
The present invention has following beneficial effect: the inventive method effect in reality processing is fine.As long as initial workpiece processing tries out elastic deformation Δ X, Bending Deformation Δ Y under allowance for finish M state, correction can be compensated in the processing of identical jobs afterwards, high-precision size, public sternly poor work pieces process can be ensured completely.In other turnery processing, the control of relieving amount also can use for reference the method, has very strong generalization.
Accompanying drawing explanation
Fig. 1 is prior art machining sketch chart figure of the present invention, Fig. 2 is the A-A cut-open view of Fig. 1, Fig. 3 is that (L1 is workpiece real contour line, L2 theoretical size machining locus by theoretical dimensioned to machining locus correction schematic diagram, L3 is according to the revised processing tool track of deformation quantity), Fig. 4 is the schematic diagram of machining locus, and Fig. 5 is the detail view of Fig. 4.
Embodiment
Embodiment one: composition graphs 1 to Fig. 5 illustrates present embodiment, the method of present embodiment comprises step one, roughing: process by accurately machined cutting depth, and workpiece to be added chooses n B point, by B1 along highly equidistant, B2, B3 ... relieving amount Δ 1, Δ 2 are measured in Bn pointwise ... Δ n, by curve C 1-Cn, by theoretical processing linear B1-Bn, be a mirror curve A1-An, B1 is measured, B2, B3 by per-spot way ... Bn point place relieving amount Δ 1, Δ 2 ... Δ n;
Step 2, calculating: to be averaged again by accurately machined cutting depth in-process measurement by several times and draw with close to theoretical relieving amount Δ 1, Δ 2 ... Δ n, obtain a point set close to Molded Line, calculate A1 again, A2, A3 ... the position of An point, by A1, A2, A3 ... adjacent 2 of An is in turn connected into straight-line segment A1A2, A2A3 ... A
n-1a
n, go out machining locus by this sets of line segments program description and process.
Due to cutter relieving, by the straight line machined cantilever mouth of pipe, produce flexural deformation, track is irregular curve C1-Cn, the size of the cutter relieving deformation produced, relevant with the material of workpiece, intensity, hardness, shape, installation way and cutter, cutting parameter etc. factor, be difficult to be solved by theoretic analysis quantum chemical method, rule can only be groped in actual process.
Press straight path processing in prior art, have cutter relieving, can only reduce cutter relieving deviate by reducing cutting depth, usual cutting depth is 0.2-0.3mm, and after improving, the machinable degree of depth is 1mm, improves working (machining) efficiency.Order is that before improving, in method, 1mm processes a cutter in addition, measures, and processes a cutter measured deviation value, quadruplication with the upper 1mm of method processing after improvement.Draw data, as the foundation of 1mm processing in finishing.
Embodiment two: composition graphs 5 illustrates present embodiment, the quantity of the selection of measuring point of present embodiment is determined according to the tolerance of theoretical processing dimension, the maximum deviation T of straight-line segment and segment of curve is less than the tolerance of processing dimension, and other embodiment is identical with embodiment one.
Embodiment three: the blade fillet that in the step one of present embodiment, roughing uses is greater than 1.5, can reduce machining locus two straight-line segment point of intersection, trail change vestige.Other embodiment is identical with embodiment one.
Embodiment four: the nc program straight-line segment track of present embodiment need perform Programing by outline instruction G64 all the time, reduces reduction machining locus two straight-line segment point of intersection that the accurate stop instruction G60 that slows down produces, trail change vestige.Other embodiment is identical with embodiment one.
Principle of work: as shown in Figure 1 to Figure 3, can take when roughing to carry out several times trial cut with the identical processing mode of last cutter of finishing and key element, one group of Φ A, Φ B, Φ C can be drawn,, Φ D, and by above-mentioned measured value, one group of Δ X under the state calculating process redundancy M identical with finishing, Δ Y, by calculating the mean value of Δ X, Δ Y, for finishing provides foundation, during finishing, process redundancy is carried out adjustment compensation by us, is: M by the process redundancy of 1
1=M+ Δ X
1+ Δ Y ,=M+ (Φ C/2-Φ B/2), by the process redundancy of 2 be: M
2=M+ Δ X
2+ Δ Y
2=M+ (Φ D2-Φ B/2,) the data foundation worked out as job sequence according to this process redundancy, cutter machining locus is allowed to become an oblique line (be mirrored state with the above-mentioned i.e. approximate oblique line of physical size profile footprint of 1 o'clock to 2 o'clock), be equivalent to process a right cylinder in theory, result processes a vertebral body for above-mentioned reasons, the machining locus carrying out a positive centrum compensates corrects the error that above-mentioned deformation workpiece normal process produces vertebral body, finally processes right cylinder.
This scheme can carry out trial cut under semi-finishing state again, observes processing effect and whether reaches perfect condition.In this way, finishing can be carried out.If any error, correction can be compensated by above-mentioned surplus compensation method.
Table 1 improves the measurement data of front method and the deviate of theoretical value
When being more than cutting depth 1mmmm under roughing flow status trial cut four times from mouth of pipe end face to apart from the mouth of pipe 190, at interval of 10mm measured value, and the reference compensated as programming of averaging.
Table 2 improves the measurement data of rear method and the deviate of theoretical value
When being more than cutting depth 1mmmm under roughing flow status trial cut four times from mouth of pipe end face to apart from the mouth of pipe 190, at interval of 10mm measured value, and the reference compensated as programming of averaging.
Can be drawn by table 1 and table 2, the little guarantee high precision of this job operation efficiency high level error.
Claims (4)
1. in a steam turbine, press the reheated steam extraction steam pipe facing head job operation of heat shield, it is characterized in that described method comprises step one, roughing: process by accurately machined cutting depth, workpiece to be added chooses n B point along highly equidistant, by B1, B2, B3 ... relieving amount Δ 1, Δ 2 are measured in Bn pointwise ... Δ n, by curve C 1-Cn, by theoretical processing linear B1-Bn, be a mirror curve A1-An, B1 is measured, B2, B3 by per-spot way ... Bn point place relieving amount Δ 1, Δ 2 ... Δ n;
Step 2, calculating: to be averaged again by accurately machined cutting depth in-process measurement by several times and draw with close to theoretical relieving amount Δ 1, Δ 2 ... Δ n, obtain a point set close to Molded Line, calculate A1 again, A2, A3 ... the position of An point, by A1, A2, A3 ... adjacent 2 of An is in turn connected into straight-line segment A1A2, A2A3 ... A
n-1a
n, go out machining locus by this sets of line segments program description and process.
2. in steam turbine according to claim 1, press the reheated steam extraction steam pipe facing head job operation of heat shield, it is characterized in that the quantity of selection of measuring point is determined according to the tolerance of theoretical processing dimension, the maximum deviation T of straight-line segment and segment of curve is less than the tolerance of processing dimension.
3. press the reheated steam extraction steam pipe facing head job operation of heat shield in steam turbine according to claim 1, it is characterized in that the blade fillet that in step one, roughing uses is greater than 1.5.
4. in steam turbine according to claim 1, press the reheated steam extraction steam pipe facing head job operation of heat shield, it is characterized in that nc program straight-line segment track need perform Programing by outline instruction G64 all the time, reduce reduction machining locus two straight-line segment point of intersection that the accurate stop instruction G60 that slows down produces, trail change vestige.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410853499.0A CN104731018A (en) | 2014-12-31 | 2014-12-31 | Method for machining reheat steam extraction pipe facing head of steam turbine medium-pressure heat shield |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410853499.0A CN104731018A (en) | 2014-12-31 | 2014-12-31 | Method for machining reheat steam extraction pipe facing head of steam turbine medium-pressure heat shield |
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| CN104731018A true CN104731018A (en) | 2015-06-24 |
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| CN201410853499.0A Pending CN104731018A (en) | 2014-12-31 | 2014-12-31 | Method for machining reheat steam extraction pipe facing head of steam turbine medium-pressure heat shield |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102495589A (en) * | 2011-11-28 | 2012-06-13 | 龚文资 | Numerical control turning programming compensating technological process |
| US20120253505A1 (en) * | 2011-04-04 | 2012-10-04 | Okuma Corporation | Method and program for calculating correction value for machine tool |
| CN102865847A (en) * | 2012-10-10 | 2013-01-09 | 北京精雕科技有限公司 | Spline curve compensation method for measuring profile deviation based on path unit |
| CN103350326A (en) * | 2013-06-28 | 2013-10-16 | 洛阳北川重工机械有限公司 | Machining technology of chuck sheet |
-
2014
- 2014-12-31 CN CN201410853499.0A patent/CN104731018A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120253505A1 (en) * | 2011-04-04 | 2012-10-04 | Okuma Corporation | Method and program for calculating correction value for machine tool |
| CN102495589A (en) * | 2011-11-28 | 2012-06-13 | 龚文资 | Numerical control turning programming compensating technological process |
| CN102865847A (en) * | 2012-10-10 | 2013-01-09 | 北京精雕科技有限公司 | Spline curve compensation method for measuring profile deviation based on path unit |
| CN103350326A (en) * | 2013-06-28 | 2013-10-16 | 洛阳北川重工机械有限公司 | Machining technology of chuck sheet |
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