A method of controlling the consistency of a blade profile

Abstract

The present application provides a kind of method for controlling the consistency of blade profile, comprising the following steps: A. free blade profile is equally divided into multiple sections;Three coordinate detection section is used, the point data of each section is obtained, and the weighted average deviation a of the section is calculated;B. using software to process a, to calculate the frequency value b, then compare b with theoretical value;C. according to the frequency value b, adjust the profile deviation value c of each section of profile;D. the profile deviation value c after adjustment is processed, to calculate the weighted average deviation d of the same section, and statistical analysis is carried out;E. control effective analysis polishing amount, separately correct the amount of overproof blade. By analyzing the profile data, the consistency of the profile is controlled according to the analysis result, the qualified rate of the profile and the free blade tuning bandwidth are controlled;According to the calculated bandwidth, the process quality is controlled, so as to control the inherent frequency of free blade itself.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of blade measurement technology, and particularly relates to a method for controlling the consistency of blade profile. BACKGROUND

[0002] In the field of blade manufacturing, the last stage blade is the most difficult type to manufacture among turbine blades, and the inherent frequency of the last stage blade itself has strict requirements for avoiding critical rotating speed during operation. Therefore, the turbine last stage blade is very sensitive to frequency, and there are three types of design, namely, conventional boss, boss + shroud, and free blade. The free blade needs to be designed with frequency adjustment, and it is also the most difficult type to manufacture.

[0003] The traditional process realizes the frequency adjustment by reworking the finished product state blade, but still has the disadvantages of low efficiency and high cost.

[0004] In summary, how to provide a method for controlling the consistency of blade profile, which can efficiently control the inherent frequency of the free blade, has become a problem to be solved by people in the field. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a method for controlling the consistency of blade profile, comprising the following steps:

[0006] A. evenly divide a free blade profile into multiple sections; use three-coordinate detection to detect the sections, obtain point data of each section, and calculate the weighted mean deviation WMD of the section, and the value of the WMD is a;

[0007] B. process all the a of the sections in a blade using software, mark the a of each section on the coordinate axis, and connect the points of each a into a straight line to form a broken line graph; then calculate the frequency value b of the multiple blades, and then compare the b with the theoretical value;

[0008] C. adjust the profile deviation value c of each section of the profile according to the frequency value b, so that it meets the design requirements;

[0009] D. process the multiple blades after adjusting the profile deviation value c, so as to calculate the weighted mean deviation WMD of the same section in the multiple blades, and the value of the WMD is d, and perform statistical analysis of the same batch;

[0010] E. control the effective analysis of polishing and removing amount, and separately correct the removing amount of the out-of-tolerance blades.

[0011] As an optimization, the free blade profile comprises an upper region, a middle region and a lower region, and each region is evenly divided into multiple sections.

[0012] As optimization, the cross-section width divided in the middle region is less than the cross-section width divided in the upper region and the cross-section width divided in the lower region.

[0013] As optimization, in step A, the three-coordinate detection cross-section mode is specifically: from the starting point of the gas outlet side (TE) → back arc side (CV) → gas inlet side (LE) → inner arc side (CC) → gas outlet side (TE) to form a cycle.

[0014] As optimization, 30-70 detection points are detected on the gas outlet side (TE) / gas inlet side (LE), and at least 600 detection points are detected on the back arc side (CV) / inner arc side (CC).

[0015] As optimization, in step B, after comparing b with the theoretical value, the bandwidth and upper and lower limits of the comprehensive milling surface control are given.

[0016] As optimization, in step E, for the out-of-tolerance blades found in the comprehensive milling process, the gear quantitative polishing value is first given, and then the separate correction is carried out.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] (1) The frequency calculation can be completed in the processing surface stage, and the mixing frequency bandwidth meets the requirements, without manual rework, the product pass rate is improved to 100%, the final detection ratio is reduced, and the cost is reduced;

[0019] (2) The surface data is analyzed, the consistency of the surface profile is controlled according to the analysis result, the surface pass rate and the free blade frequency bandwidth are controlled in this way, the process quality is controlled according to the calculated bandwidth, and the inherent frequency of the free blade itself is controlled. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present application, the following will briefly introduce the drawings needed in the specific embodiments. In all the drawings, the elements or parts are not necessarily drawn according to the actual proportion.

[0021] Fig. 1 It is a detection cross-section equal division diagram of the free blade surface of the present application.

[0022] Fig. 2 It is a three-coordinate detection mode diagram of the present application. DETAILED DESCRIPTION

[0023] The embodiments of the technical scheme of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical scheme of the present application, and therefore only serve as examples, but cannot limit the protection scope of the present application.

[0024] Embodiment: as shown in the figure, a method for controlling the consistency of blade profile, specifically: Figs. 1-2

[0025] (1) evenly divide the free blade profile into eleven sections, and name them; define the way of detecting the sections, from the starting point 1, the outflow side (TE) → the back arc side (CV) → the inflow side (LE) → the inner arc side (CC) → the outflow side (TE) to form a cycle. Detect 30-70 detection points on the outflow side (TE) / inflow side (LE), and at least 600 detection points on the back arc side (CV) / inner arc side (CC).

[0026] (2) process and detect according to the drawing tolerance band, and calculate the WMD of a single processed blade based on this: a.

[0027] (3) calculate the frequency value b using the measured a of all gears in a single blade, and compare it with the theoretical frequency to give the bandwidth and upper and lower limits of comprehensive milling profile control, for example, the frequency-insensitive section is controlled within ±0.2mm, and the frequency-sensitive section is controlled within ±0.1mm.

[0028] (4) process multiple blades after adjusting the profile deviation value c, and calculate the weighted average deviation WMD of the same gear in multiple blades, the value of which is d, and perform statistical analysis on the same batch.

[0029] (5) polish the uniformity of the rated amount of removal, for example, the back arc side (CV) / inner arc side (CC) removal is controlled within 0.08-0.12mm, and the outflow side (TE) / inflow side (LE) removal is controlled within 0.05-0.08mm. For the out-of-tolerance blades found in the comprehensive milling process, give the quantitative polishing value of the gear, for example, S5 / S6 is polished by 0.18mm, and S7 / S8 is polished by 0.22mm.

[0030] In implementation, the free blade profile includes an upper region 2, a middle region 3 and a lower region 4, and each region is evenly divided into multiple sections 5. The width of the section divided in the middle region 3 is smaller than the width of the section divided in the upper region 2 and the width of the section divided in the lower region 4.

[0031] After adopting the above-mentioned method for controlling the consistency of blade profile, the consistency of the polished profile is basically controlled within ±0.15mm, and the static frequency detection value meets the required range of the standard piece and the mixed frequency piece.

[0032] The present application can process the blade to the frequency range required by the drawing, effectively avoiding human intervention, canceling the frequency repair work, and improving the qualified rate to 100%. With the improvement of quality, the production cost is reduced, and the delivery cycle is shortened.

[0033] ​The above examples are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some or all of the technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the specification of the present application.

Claims

1. A method for controlling the consistency of blade profile, characterized in that, Includes the following steps: A. Divide a free blade profile into multiple equal sections; The cross-section is detected using a three-coordinate measuring machine to obtain the point data of each section, and the weighted average deviation (WMD) of the point data of that section is calculated. The value of WMD is a. B. Use software to process the 'a' values ​​of all positions in a blade, mark the 'a' values ​​of each position on the coordinate axis, and connect the points of each 'a' value to form a straight line graph; thereby calculate the frequency values ​​'b' of multiple blades, and then compare 'b' with the theoretical value. C. Adjust the profile deviation value c of each position of the profile according to the frequency value b to meet the design requirements; D. Process multiple blades after adjusting the profile deviation value c, and calculate the weighted average deviation WMD of the point data of the same gear in multiple blades. The value of WMD is d. Perform statistical analysis on the same batch. E. Control the effective analysis of polishing removal. For blades that exceed the tolerance in the comprehensive milling process, first give the quantitative polishing value for the gear, and then perform separate correction to remove excess material.

2. The method for controlling the consistency of blade profile according to claim 1, characterized in that, The free blade profile includes an upper region, a middle region, and a lower region, each region being evenly divided into multiple cross sections.

3. The method for controlling the consistency of blade profile according to claim 2, characterized in that, The width of the cross-section divided equally in the middle region is smaller than the width of the cross-section divided equally in the upper region and the width of the cross-section divided equally in the lower region.

4. The method for controlling the consistency of blade profile according to claim 1, characterized in that, In step A, the three-coordinate measuring machine is used to detect the cross section as follows: a loop is formed from the starting point exhaust side → back arc side → intake side → inner arc side → exhaust side.

5. The method for controlling the consistency of blade profile according to claim 4, characterized in that, 30-70 test points are tested on the exhaust and intake sides, and at least 600 test points are tested on the back arc and inner arc sides.

6. The method for controlling the consistency of blade profile according to claim 1, characterized in that, In step B, after comparing b with the theoretical value, the bandwidth and upper and lower limits of the comprehensive milling surface control are given.

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