A turning process and detection method for a disc-shaped special-shaped blade root groove

Abstract

This invention relates to a turning process and inspection method for irregular blade root grooves on a wheel. The turning process includes: S1: using a rhomboid cutting tool to perform rough and finish turning on the outer circle of the wheel; S2: first using a cutting tool to rough turn straight grooves and the bottom diameter from the outer circle inwards on the wheel, then using two additional cutting tools to perform semi-finish and finish cutting on the straight grooves; S3: using a cavity turning tool to rough machine the half-section, weight-reducing groove, and working surface from the inside out, then finishing the bottom diameter and half-section, while simultaneously performing semi-finish machining on the weight-reducing groove and working surface; S4: using a cavity turning tool to finish machine the weight-reducing groove and working surface; S5: using a cutting tool to successively rough and finish turn the section and filling groove. The inspection method includes measuring the width of the straight groove and section, measuring the cavity of the half-section, and measuring the symmetry of the blade root groove. Using the above turning process and inspection method can improve the machining quality and efficiency of irregular blade root grooves.

Description

Technical Field

[0001] This invention relates to the field of wheel machining technology, and in particular to a turning process for irregular blade root grooves of wheel discs, and a subsequent inspection method for irregular blade root grooves of wheel discs. Background Technology

[0002] With the continuous development and innovation of steam turbine technology, patent CN112797025B discloses a rotating device with an irregular structure for the blade root groove without openings. However, since most wheel disk parts are broached to complete the blade root groove machining, the blade root grooves of wheel disk parts are often side-mounted. Furthermore, since the machining processes or methods for rotor blade root groove machining, clamping, and measurement are relatively mature, circumferentially arranged blade root grooves often appear on rotor parts. This wheel disk turning of circumferentially arranged blade root grooves is the first of its kind.

[0003] Given that this is the first time such an irregular blade root groove structure has appeared, and that it differs significantly from the T-shaped blade root groove structure on conventional rotors, using existing T-shaped blade root groove machining technology would result in significant positional limitations during turning, requiring additional cutting tests. This not only makes it difficult to guarantee the machining quality of the irregular blade root groove, but also leads to low machining efficiency. Therefore, it is necessary to design a turning process and inspection method specifically for this type of irregular blade root groove to ensure batch processing and improve machining efficiency. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a turning process for the root groove of the disc blade that can improve the machining quality and machining efficiency.

[0005] The present invention adopts the following technical solution:

[0006] This invention provides a turning process for a shaped blade root groove on a wheel. The shaped blade root groove has an axisymmetric structure. On one side of the axis of symmetry, the shaped blade root groove extends obliquely from the outer circle of the wheel towards the inward direction as a segment. The end of the segment continues to extend towards the inward direction of the wheel as a straight groove. The end of the straight groove extends laterally to form a working surface. The end of the working surface continues to extend towards the inward direction of the wheel as a weight-reducing groove. The end of the weight-reducing groove continues to extend towards the inward direction of the wheel as a half-section. The end of the half-section extends laterally to form a bottom diameter. A recess on the bottom diameter forms a filling groove. The process includes the following steps:

[0007] S1: Use a diamond-shaped cutting tool to perform rough turning and finish turning on the outer circle of the wheel in sequence;

[0008] S2: First, use a cutting tool to rough cut the straight groove and bottom diameter from the outer circle of the wheel to the inside in a layered cutting manner. Then, take two more cutting tools and use them in an offset state to perform semi-finishing and finishing cutting on the straight groove.

[0009] S3: Using a cavity turning tool, rough machining is first performed on the half-section, weight reduction groove and working surface from the inside out, and then the bottom diameter and half-section are finished. At the same time as finishing, the weight reduction groove and working surface are semi-finished.

[0010] S4: Use cavity turning tools to finish the weight reduction groove and working surface;

[0011] S5: Use a cutting tool to rough turn and finish turn the small sections and filling grooves in sequence.

[0012] Preferably, in step S1, after rough turning the outer circle of the wheel, a allowance of 0.8-1mm is retained, and the finish turning of the outer circle of the wheel is performed in three stages. The depth of cut of the first finish turning of the outer circle is 0.4-0.5mm, the depth of cut of the second finish turning of the outer circle is 0.20-0.25mm, and after the third finish turning of the outer circle, the outer circle of the wheel reaches the size required by the process step drawing.

[0013] Preferably, in step S2, both the straight groove and the bottom diameter retain a margin of 2-3 mm after rough turning; and the straight groove has a margin of 0.10-0.15 mm after semi-finishing, and then the straight groove is finished to meet the dimensions required in the process step diagram through finishing.

[0014] Preferably, in step S3, the half-section, weight-reducing groove, and working surface are first rough-machined at a feed rate of 0.08 mm / min-0.2 mm / min, leaving a margin of 0.8-1 mm after rough machining; then the bottom diameter and half-section are finished. The finishing of the half-section is performed in three stages, with the depth of cut for the first finishing of the half-section being 0.4-0.5 mm, the depth of cut for the second finishing of the half-section being 0.2-0.25 mm, and the third finishing of the half-section adjusting the half-section to the dimensions required in the process step diagram; when the third finishing of the half-section is completed and the cavity turning tool moves to the position of the weight-reducing groove, the feed rate is changed to 0.12 mm / min-0.2 mm / min for the semi-finishing of the weight-reducing groove and the working surface, and both the weight-reducing groove and the working surface leave a margin of 0.2-0.3 mm after the semi-finishing.

[0015] Preferably, in step S4, the finishing of the working surface is carried out in two steps, and the cutting depth of the finishing of the working surface in both steps is 0.10-0.15mm. The weight reduction groove is also processed together during the second finishing of the working surface.

[0016] Preferably, in step S5, when rough turning the section with a cutting tool, a transition chamfer is also machined between the section and the straight groove. The finishing of the section is performed in two steps, and the depth of cut for each finishing of the section is 0.4-0.5 mm.

[0017] The present invention also provides a method for detecting the blade root groove of a wheel disc, including the detection of the width of the straight groove and the section, the detection of the cavity of the half-section, and the detection of the symmetry of the blade root groove. When the turning process of the wheel disc's irregular blade root groove reaches the machining of the half-section, the cavity of the half-section is detected; after the turning process of the wheel disc's irregular blade root groove is completed and the machining of the wheel disc's irregular blade root groove is finished, the detection of the width of the straight groove and the section and the detection of the symmetry of the blade root groove are performed.

[0018] Preferably, the width detection of the straight groove and the section is completed by a go / stop plate.

[0019] Preferably, the cavity inspection of the half-section is completed using an inside micrometer.

[0020] Preferably, the symmetry of the blade root groove is tested by using a profile symmetry test template with a feeler gauge.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The turning process of the irregular blade root groove of the wheel disc of the present invention can utilize a variety of cutting tools, including rhomboid cutters, cutting tools, and cavity turning tools, to perform the machining of irregular blade root grooves on a dedicated wheel disc front turning machine. Without increasing equipment costs too much, the machining of irregular blade root grooves on the wheel disc is achieved through a specific process sequence of S1-S5, reducing costs and effectively improving machining quality and efficiency.

[0023] The method for detecting the irregular blade root groove of the present invention can perform standardized and effective detection of the machining dimensions of the irregular blade root groove after the irregular blade root groove has been machined and turned in half or after the whole is completed by the above process, so as to ensure the machining quality of the irregular blade root groove. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the irregular blade root groove after processing in an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram illustrating the state of machining the outer circle of a wheel disc using a turning process for machining the root groove of the wheel disc's irregular blade in an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram illustrating the rough turning of the straight groove and bottom diameter using a turning process for the root groove of a disc-shaped blade in an embodiment of the present invention.

[0027] Figure 4 This is a schematic diagram illustrating the semi-finishing and finishing of a straight groove using a turning process for a wheel-shaped blade root groove in an embodiment of the present invention.

[0028] Figure 5This is a schematic diagram illustrating the rough machining of the half-section, weight reduction groove, and working surface using a turning process with a wheel-shaped blade root groove in an embodiment of the present invention.

[0029] Figure 6 This is a schematic diagram illustrating the state of finishing the bottom diameter and half-section using a turning process with a wheel-shaped blade root groove in an embodiment of the present invention.

[0030] Figure 7 This is a schematic diagram illustrating the state of finishing the weight reduction groove and working surface using the turning process of the wheel disc irregular blade root groove in an embodiment of the present invention.

[0031] Figure 8 This is a schematic diagram illustrating the state of rough turning and finish turning of the section and the gap-filling groove in sequence using the turning process of the wheel-shaped blade root groove in an embodiment of the present invention.

[0032] Figure 9 This is a schematic diagram of the go / stop plate used in the detection method of the wheel-shaped blade root groove in this embodiment of the invention to detect the width of the straight groove and the section.

[0033] Figure 10 This is a schematic diagram illustrating the state of a half-section cavity during the detection of a wheel-shaped blade root groove using a detection method according to an embodiment of the present invention.

[0034] Figure 11 This is a schematic diagram of the state when the symmetry of the blade root groove is detected using the detection method of the wheel-shaped blade root groove in an embodiment of the present invention.

[0035] The reference numerals in the attached figures are explained as follows:

[0036] 1. Section 8. Go / No Stop Plate

[0037] 2. Straight groove 801, through end

[0038] 3. Working face 802, stop end

[0039] 4. Weight reduction groove; 9. Inside micrometer

[0040] 5. Half-section 10. Shape line symmetry inspection template

[0041] 6. Base diameter 11, outer circle

[0042] 7. Gap Filler A, Axial Reference Surface Detailed Implementation

[0043] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0044] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0047] This embodiment provides a turning process for irregular blade root grooves on a wheel disc. See [link to documentation]. Figure 1 The irregular blade root groove has an axisymmetric structure. On one side of the axis of symmetry, the irregular blade root groove extends obliquely from the outer circle 11 of the wheel disk into a segment 1. The end of segment 1 continues to extend into the wheel disk into a straight groove 2. The end of straight groove 2 extends laterally into a working surface 3. The end of working surface 3 continues to extend into the wheel disk into a weight-reducing groove 4. The end of weight-reducing groove 4 continues to extend into the wheel disk into a half-section 5. The end of half-section 5 extends laterally into a bottom diameter 6. A recessed filling groove 7 is formed on the bottom diameter 6. The following steps are included, see [link to relevant documentation]. Figures 2 to 8 :

[0048] S1: Use a diamond-shaped cutting tool to perform rough turning and finish turning on the outer circle 11 of the wheel in sequence;

[0049] S2: First, use a cutting tool to rough cut the straight groove 2 and the bottom diameter 6 from the outer circle 11 of the wheel to the inside in a layered cutting manner. Then, take two other cutting tools to perform semi-finishing and finishing cutting on the straight groove 2 in an offset state.

[0050] S3: Using a cavity turning tool, rough machining is first performed on half 5, weight reduction groove 4 and working surface 3 from the inside out, then finish machining is performed on bottom diameter 6 and half 5, and semi-finish machining is performed on weight reduction groove 4 and working surface 3 at the same time as finish machining.

[0051] S4: Use a cavity turning tool to finish the weight reduction groove 4 and the working surface 3;

[0052] S5: Use a cutting tool to rough turn and finish turn section 1 and the gap filling groove 7 in sequence.

[0053] The turning process of the irregular blade root groove on the wheel in this embodiment can utilize a variety of cutting tools, including rhomboid cutters, cutting tools, and cavity turning tools, to process the irregular blade root groove on a dedicated wheel front turning machine. Without increasing equipment costs too much, the processing of the irregular blade root groove on the wheel is achieved through the specific process sequence of S1-S5, reducing costs and effectively improving both processing quality and processing efficiency.

[0054] It should be noted that, see Figure 1 Section 1 is a straight line shape that determines the position and geometric elements of the tenon or tenon groove; 2 is a straight line shape that mates with the root of the blade; 3 is the load-bearing surface of the tenon or tenon groove in the blade root groove during operation; 4 is an arc-shaped groove used to reduce structural weight and improve mechanical efficiency; 5 is a straight line shape that helps the blade and the wheel to fit tightly; 7 is a caulking groove for placing caulking strips to ensure that the blade is correctly installed in the blade root groove and can withstand the working load.

[0055] Preferably, in step S1, after rough turning the outer circle 11 of the wheel disk, a allowance of 0.8-1mm is retained, and the finish turning of the outer circle of the wheel disk is performed in three stages. The depth of cut of the first finish turning of the outer circle is 0.4-0.5mm, the depth of cut of the second finish turning of the outer circle is 0.20-0.25mm, and after the third finish turning of the outer circle, the outer circle of the wheel disk reaches the size required by the process step drawing, thereby completing the turning of the outer circle of the wheel disk with a special tool and under the specified cutting parameters.

[0056] It should be noted that the actual dimensions of the outer circle of the wheel after machining are rounded up to the nearest integer.

[0057] Preferably, in step S2, see Figure 3 First, a cutting tool with a width of 15.875mm is used to cut the straight groove 2 and the bottom diameter 6 in layers, and both the straight groove 2 and the bottom diameter 6 retain a 2-3mm allowance after rough turning; see [link to documentation]. Figure 4 Then, two cutting blades with a width of 8mm are used to perform semi-finishing and finishing cutting on the straight groove 2 in an offset state. The allowance of the straight groove 2 after semi-finishing is 0.10-0.15mm. Then, the straight groove 2 is finished to meet the dimensions required in the process step diagram.

[0058] Preferably, in step S3, the cavity turning tool performs turning in a rotor-reverse manner, see [reference needed]. Figure 5First, rough-machine the half-section 5, the weight-reducing groove 4, and the working surface 3 at a feed rate of 0.08 mm / min-0.2 mm / min, and retain a allowance of 0.8-1 mm after rough machining; see [link to documentation]. Figure 6 Next, the bottom diameter 6 and half-section 5 are finished. The finishing of half-section 5 is carried out in three stages. The depth of cut for the first finishing of half-section 5 is 0.4-0.5mm, the depth of cut for the second finishing of half-section 5 is 0.2-0.25mm, and the third finishing of half-section 5 is adjusted to the dimensions required in the process step drawing. After the third finishing of half-section 5 is completed and the cavity turning tool moves to the position of the weight reduction groove 4, the feed rate is changed to 0.12mm / min-0.2mm / min and the weight reduction groove 4 and the working surface 3 are semi-finished. After the semi-finishing of weight reduction groove 4 and working surface 3, a margin of 0.2-0.3mm is retained.

[0059] Preferably, in step S4, see Figure 7 The finishing of working surface 3 is carried out in two stages. The cutting depth of both finishing stages is 0.10-0.15mm. The weight reduction groove 4 is also processed together during the second finishing stage to avoid the appearance of burrs in the cavity and ensure the processing quality.

[0060] Preferably, in step S5, see Figure 8 When rough turning section 1 with a cutting tool, a transition chamfer is also machined between section 1 and straight groove 2. The finishing of section 1 is carried out in two stages, and the depth of cut for each finishing of section 1 is 0.4-0.5mm.

[0061] This embodiment also provides a method for detecting the blade root groove of a wheel disc, including the detection of the width of the straight groove and the segment, the detection of the cavity of the half-section, and the detection of the symmetry of the blade root groove. When the turning process of the wheel disc's irregular blade root groove reaches the machining of the half-section 5, the cavity of the half-section is detected. After the turning process of the wheel disc's irregular blade root groove is completed and the machining of the wheel disc's irregular blade root groove is finished, the detection of the width of the straight groove and the segment and the detection of the symmetry of the blade root groove are performed.

[0062] The method for detecting the irregular blade root groove of the wheel in this embodiment can perform standardized and effective detection of the machining dimensions of the irregular blade root groove after the irregular blade root groove has been machined into half and the whole part has been completed through the above process, so as to ensure the machining quality of the irregular blade root groove.

[0063] Preferably, the width detection of the straight groove 2 and the section 1 is completed by the go / stop plate 8. See [link / reference] Figure 9 If the through end 801 of the through / stop plate 8 can pass through the straight groove 2 or the section 1, and the stop end 802 of the through / stop plate 8 cannot pass through the straight groove 2 or the section 1, then the width dimension of the straight groove 2 or the section 1 is qualified.

[0064] Preferably, the cavity inspection of the half-section is performed using an inside micrometer 9. See also Figure 10 Using the side of the straight groove 2 as the axial reference plane A, use an inside micrometer 9 to measure the straight distance between half 5 and the axial reference plane A. Then compare this measurement data with the dimensional data in the process step diagram to obtain the tool offset when machining half 5. Then continue to machine half 5 according to the tool offset to make the cavity size of half 5 qualified.

[0065] Preferably, the symmetry of the blade root groove is checked using a profile symmetry inspection template 10 paired with a feeler gauge (not shown in the figure). See also Figure 11 First, the profile symmetry inspection template 10 is placed against one side of the working surface 3, and the bent section of the profile symmetry inspection template 10 is aligned with the straight groove 2 on that side. Then, a feeler gauge is inserted into the gap between the profile symmetry inspection template 10 and the straight groove 2 and the gap is completely sealed. After recording the gap size measured by the feeler gauge, the profile symmetry inspection template 10 is placed against the other side of the working surface 3, and the bent section of the profile symmetry inspection template 10 is aligned with the straight groove 2 on that side. The feeler gauge is then inserted into the gap between the profile symmetry inspection template 10 and the straight groove 2 and the gap is completely sealed. The gap size measured by the feeler gauge is recorded again. By comparing the two recorded gap sizes, it can be determined whether the symmetry of the blade root groove is qualified.

[0066] This invention can complete the machining of irregular blade root grooves by using the fixed step sequence and cutting parameters in the above-mentioned turning process, and then complete the dimensional inspection of irregular blade root grooves by using the above-mentioned standard inspection method, so as to ensure the machining efficiency and quality of irregular blade root grooves. Moreover, the machining machine tools and inspection tools are relatively common, making it convenient and efficient in actual use.

[0067] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A turning process for a rotary disc blade root groove, characterized in that, The irregular blade root groove is an axisymmetric structure. On one side of the axis of symmetry, the irregular blade root groove extends from the outer circle (11) of the wheel disk inward to form a section (1). The end of the section (1) continues to extend towards the inside of the wheel disk to form a straight groove (2). The end of the straight groove (2) extends laterally to form a working surface (3). The end of the working surface (3) continues to extend towards the inside of the wheel disk to form a weight-reducing groove (4). The end of the weight-reducing groove (4) continues to extend towards the inside of the wheel disk to form a half-section (5). The end of the half-section (5) extends laterally to form a bottom diameter (6). A recessed filling groove (7) is formed on the bottom diameter (6). The machining of the irregular blade root groove is carried out on a special wheel disk front turning machine and includes the following steps: S1: Use a diamond-shaped tool to perform rough turning and finish turning on the outer circle (11) of the wheel in sequence; after rough turning the outer circle (11) of the wheel, leave a margin of 0.8-1mm, and finish turning the outer circle of the wheel is performed in three stages. The depth of cut of the first finish turning of the outer circle is 0.4-0.5mm, the depth of cut of the second finish turning of the outer circle is 0.20-0.25mm, and after the third finish turning of the outer circle, the outer circle of the wheel reaches the size required by the process step drawing; S2: First, use a cutting tool to rough cut the straight groove (2) and the bottom diameter (6) from the outer circle (11) of the wheel disc in a layered cutting manner. Then, take two other cutting tools to perform semi-finishing and finishing cutting on the straight groove (2) in an offset state. The straight groove (2) and the bottom diameter (6) retain a 2-3mm allowance after roughing. The allowance of the straight groove (2) after semi-finishing is 0.10-0.15mm. Then, finish cutting is used to make the straight groove (2) reach the size required by the process step diagram. S3: Using a cavity turning tool, rough machining is first performed on the half-section (5), the weight-reducing groove (4), and the working surface (3) from the inside out. Then, the bottom diameter (6) and the half-section (5) are finished. At the same time as finishing, the weight-reducing groove (4) and the working surface (3) are semi-finished. First, the half-section (5), the weight-reducing groove (4), and the working surface (3) are rough machined at a feed rate of 0.08 mm / min-0.2 mm / min. After the rough machining is completed, the rough machining is retained. 0.8-1mm allowance; then the bottom diameter (6) and the half (5) are finished. The finishing of the half (5) is carried out in three stages. The cutting depth of the first half finishing is 0.4-0.5mm, the cutting depth of the second half finishing is 0.2-0.25mm, and the third half finishing adjusts the half (5) to the size required in the process step diagram. When the third half finishing is completed and the cavity turning tool moves to the position of the weight reduction groove (4), the feed speed is changed to 0.12 mm / min - 0.2mm / min and the semi-finishing of the weight reduction groove (4) and the working surface (3) is carried out. The weight reduction groove (4) and the working surface (3) retain a 0.2-0.3mm allowance after the semi-finishing is completed. S4: Use a cavity turning tool to finish the weight reduction groove (4) and the working surface (3); the finishing of the working surface (3) is carried out in two stages, and the depth of cut for the finishing of the working surface in both stages is 0.10-0.15mm. The weight reduction groove (4) is also processed together during the second finishing of the working surface. S5: The section (1) and the filling groove (7) are cut out by rough turning and finish turning in sequence using a cutting tool; when the section (1) is rough turned by the cutting tool, a transition chamfer is also processed between the section (1) and the straight groove (2). The finish machining of the section (1) is carried out in two stages, and the depth of cut for each finish machining of the section is 0.4-0.5mm.

2. A method for detecting irregular blade root grooves on a wheel, characterized in that, The process includes width detection of straight grooves and segments, cavity detection of half-sections, and symmetry detection of blade root grooves. When the turning process of the special blade root groove of the wheel disc described in claim 1 reaches the machining of half-section (5), the cavity detection of half-section is performed. The cavity detection of half-section is completed by an inside micrometer (9). Taking the side of one straight groove (2) as the axial reference plane (A), the straight distance between half-section (5) and axial reference plane (A) is measured by the inside micrometer (9). The measured data is then compared with the dimensional data in the process step diagram to obtain the tool offset when machining half-section (5). The half-section (5) is then machined according to the tool offset to make the cavity size of half-section (5) qualified. After the machining of the special blade root groove of the wheel disc is completed in the turning process of the special blade root groove of the wheel disc described in claim 1, the width detection of straight grooves and segments and the symmetry detection of blade root grooves are performed.

3. The method for detecting irregular blade root grooves of a wheel according to claim 2, characterized in that, The width detection of the straight groove (2) and the section (1) is completed by the go / stop plate (8).

4. The method for detecting irregular blade root grooves of a wheel according to claim 2, characterized in that, The symmetry of the blade root groove is tested by using a profile symmetry test template (10) with a feeler gauge.

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