JP6376693B2 - Shroud milling amount determination method and rotor manufacturing method - Google Patents

Description

  The present invention relates to a shroud cutting amount determination method and a rotor manufacturing method.

  For example, when assembling a rotor such as a turbine or a compressor, a moving blade row is formed by sequentially arranging a plurality of moving blades along the circumferential direction of a disk-shaped disk. A plurality of blade grooves provided along the circumferential direction of the disk are formed. A blade groove | channel is a groove | channel provided so that the said disk might be penetrated along the axial direction of a disk. A moving blade row is formed by fitting the moving blade from one side in the axial direction of the disk into the blade groove.

  By the way, in recent years, pre-twisted blades to which a torsion amount is given in advance along the extending direction of the moving blades are widely used. When such pre-twist blades are arranged on a disk, the shrouds of adjacent blades are pressed against each other, so that the entire blade is twisted back, and a pre-designed twist amount is obtained. Fixed.

  Thus, since a pressing force based on a pre-twist is generated between the shrouds, it is necessary to assemble the moving blades against the pressing force when arranging the rotor blades on the disk. In other words, a heavy burden is imposed on the operator during assembly.

  As a technique for reducing such a burden, for example, a technique described in Patent Document 1 is known. In the turbine rotor blade described in Patent Document 1, the inclined surface of the integral cover integrally formed on the radially outer side of the blade portion, that is, the normal line of the surface contacting the integral cover of the adjacent rotor blade, It is formed so as not to intersect the region where the part is located. As a result, the circumferential force acting on the integral cover can be reduced.

  By the way, the moving blade is generally provided by being cut by a machining center or the like. That is, when the moving blade is fitted into the disk, final assembly is performed through temporary assembly and re-cutting in order to absorb dimensional errors that occur during cutting.

  As an example of such an assembly method, the following method has been proposed. First, five moving blades are temporarily assembled on a disk as one blade group. At this time, the shrouds provided on the moving blades come into contact with each other, so that among the five moving blades, the moving blade temporarily assembled later causes an axial displacement with respect to the disk. In particular, the platform forming the end of the rotor blade on the disk side is in a state in which steps are formed along the axial direction of the disk. The amount of shaving of the contact surfaces between the shrouds is determined by performing arithmetic processing based on the level difference of the platform. Next, the shroud is cut according to the amount of cutting. As a result, the five moving blades are arranged under a predetermined pre-twist amount. By repeating the above process for the remaining blade group, all the moving blades are arranged on the disk.

Japanese Patent No. 4179282

  However, in the turbine rotor blade of Patent Document 1, it is assumed that the inclined surface of the integral cover is processed with a shape and dimensions as designed. For this reason, when the above error correction in the assembly process is performed, not only the assembly accuracy is impaired, but also the assembly process may be complicated.

  Further, in the above-described method of determining the shroud shaving amount based on the step amount of the moving blade platform, in addition to the platform and the shroud being separated from each other, the shroud shaving amount is determined through arithmetic processing. Therefore, there is a possibility that a large error occurs with respect to the amount of cutting actually required. In addition, it is necessary to repeat temporary assembly, step measurement, cutting, and assembly for each blade group, which may lead to a longer construction period and a complicated process.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a shroud cutting amount determination method and a rotor manufacturing method that are simple and have sufficient accuracy.

  In the shroud cutting amount determination method according to an aspect of the present invention, the contact surfaces of the shrouds of the pair of blades are brought into contact with the blade grooves of the disk provided with the pair of adjacent blades. The spread dimension acquisition step of acquiring the spread dimension in the circumferential direction in the shroud of the pair of rotor blades, and the correlation between the spread dimension, the previously acquired spread dimension and the pre-twist amount of the rotor blade And a shaving amount determining step for determining a shaving amount of one of the contact surfaces of the pair of shrouds that are in contact with each other so that the pre-twist amount of the pair of moving blades is an arbitrary value based on the relationship. .

  According to this method, the spread dimension in the circumferential direction of the shroud is acquired in the spread dimension acquisition step, and the scraping amount of the contact surface is determined based on the correlation between the spread dimension and the pre-twist amount in the scraping amount determination process. . That is, the amount of cutting of the contact surface of the shroud that is the cutting object is determined based on the dimension of the shroud that is the cutting object in the circumferential direction. Thereby, the error contained in the amount of cutting can be reduced compared with the case where the amount of cutting is determined based on the spread dimension of the part different from the shroud that is the cutting target.

  In the shroud cutting amount determination method according to an aspect of the present invention, only one of the pair of adjacent blades is inserted into the blade groove of the disk provided with the blade, and the one of the blades is moved. A reference position of the blade is detected, and only the other blade of the pair of adjacent blades is inserted into a blade groove of the disk on which the blade is provided, and the reference position of the other blade is determined. A reference position detecting step for detecting, and the expanding dimension acquiring step includes a circumferential dimension of the pair of shrouds when the pair of blades are inserted so that contact surfaces of the shrouds contact each other. May be obtained by comparing the detected circumferential dimension with the reference position of the one moving blade and the reference position of the other moving blade.

  According to this method, it is only necessary to compare the reference positions of the pair of blades with the circumferential dimensions of the pair of shrouds when the pair of blades are inserted so that the contact surfaces are in contact with each other. The spread dimension can be acquired. Thereby, the amount of cutting of the contact surface can be determined easily and precisely.

  In the shroud cutting amount determination method according to an aspect of the present invention, the spread dimension acquisition step, the reference position detection step, and the cutting amount determination step are sequentially performed over the entire circumference of the disk for a pair of adjacent moving blades. It may be broken.

  According to this method, it is possible to easily determine the cutting amount for all the moving blades by simply repeating the same process over the entire circumference of the disk.

  A rotor manufacturing method according to another aspect of the present invention is a rotor manufacturing method using the shroud cutting amount determination method according to any one of the above aspects, wherein the cutting amount determined in the cutting amount determination step is the same. A cutting step of cutting the contact surface of the shroud, and an insertion step of sequentially inserting the moving blades having the contact surface cut into the blade groove.

  According to this method, the moving blades whose contact surfaces have been appropriately cut by the cutting amount determination step and the cutting step can be collectively inserted into the blade grooves in the insertion step. That is, when inserting the rotor blade into the blade groove, the rotor can be easily manufactured without causing rework or repetition of other processes.

  According to the present invention, it is possible to provide a shroud cutting amount determination method and a rotor manufacturing method that are simple and have sufficient accuracy.

It is the principal part enlarged view which looked at the rotor which concerns on embodiment of this invention from the axial direction. It is the principal part enlarged view which looked at the rotor which concerns on embodiment of this invention from the radial direction outer side. It is a figure which shows a part of process concerning the shroud cutting amount determination method which concerns on embodiment of this invention, and the manufacturing method of a rotor. It is a figure which shows a part of process concerning the shroud cutting amount determination method which concerns on embodiment of this invention, and the manufacturing method of a rotor. It is a figure which shows a part of process concerning the shroud cutting amount determination method which concerns on embodiment of this invention, and the manufacturing method of a rotor. It is a figure which shows a part of process concerning the shroud cutting amount determination method which concerns on embodiment of this invention, and the manufacturing method of a rotor. It is a graph which shows the relationship between the amount of pre-twist and the spreading dimension of a moving blade which concerns on embodiment of this invention. It is a flowchart which shows each process of the shroud cutting amount determination method which concerns on embodiment of this invention. It is a flowchart which shows each process of the manufacturing method of the rotor which concerns on embodiment of this invention.

(Rotor, blade)
A rotor 1 according to this embodiment will be described with reference to the drawings.
As shown in FIG. 1, the rotor 1 includes a substantially columnar rotor body 10 extending along the axis O, a disk 20 provided so as to surround the outer periphery of the rotor body 10, and an outer peripheral surface of the disk 20. And a plurality of moving blades 30 arranged in the circumferential direction.

  The rotor body 10 is a rotating body that is provided inside a turbine such as a steam turbine and is supported so as to be rotatable around the axis O. A plurality of rotor blades 30 are provided on the outer peripheral surface of the rotor body 10 along the circumferential direction of the rotor 1 via the disk 20. The plurality of blades 30 form one blade row. Further, the rotor body 10 is provided with a plurality of stages of such blade rows with gaps 50 in the direction of the axis O of the rotor 1. In the following description, a direction along the axis O of the rotor 1 and a direction around the axis O are simply referred to as an axis O direction and a circumferential direction, respectively.

  The rotor 1 configured in this manner is housed in a turbine casing (not shown). A plurality of vane rows are provided in the casing along the direction of the axis O. The turbine blades are formed by alternately arranging the stationary blade rows and the moving blade rows along the direction of the axis O. In the case of a steam turbine, the rotor 1 rotates when high-temperature and high-pressure steam is supplied to the turbine flow path. The rotational motion of the rotor 1 is taken out by an external generator or the like connected to the turbine and used for power generation or the like.

  Next, the attachment structure of the moving blade 30 to the moving blade 30 and the rotor 1 (disk 20) will be described in detail. As shown in FIG. 1, a plurality of blade grooves 40 arranged at intervals along the circumferential direction are formed on the outer peripheral surface of the disk 20. Each blade groove 40 is a groove formed so as to be recessed radially inward from the outer peripheral surface of the disk 20. Further, the blade groove 40 is open on both sides in the direction of the axis O. That is, the blade groove 40 passes through the disk 20 in the direction of the axis O.

  On the pair of wall surfaces 41 of the blade groove 40 in the circumferential direction, a plurality of teeth 42 that are continuous in a saw blade shape are formed. The pair of wall surfaces 41 on which such teeth 42 are formed are formed so that the circumferential spacing is gradually reduced from the radially outer side toward the inner side, so that the V wall shape is substantially V-shaped when viewed from the axis O direction. There is no. Specifically, the wall surfaces 41 are line symmetric with respect to a reference line extending along the radial direction through the center (axis O) of the rotor 1. In the following description, this radial reference line is referred to as a moving blade reference line Dp.

  Specifically, as shown in FIG. 3, the moving blade 30 includes a fixing 31 that fits into the blade groove 40 on the disk 20, a rectangular plate-like platform 32 that is provided radially outside the fixing 31, and a radial direction from the platform 32. It has the wing | blade part 33 extended toward an outer side, and the shroud 34 provided in the edge part of the radial direction outer side of the wing | blade part 33. As shown in FIG.

  The fixing 31 has a substantially wedge shape when viewed from the direction of the axis O so as to correspond to the substantially V-shaped blade groove 40. On the pair of wall surfaces in the circumferential direction of the fixing 31, serrations 31 </ b> A having shapes corresponding to the blade grooves 40 and the teeth 42 are respectively formed. That is, the blades 40 and the serrations 31 </ b> A mesh with each other, so that the rotor blades 30 are supported on the rotor 1 via the disks 20. Although details will be described later, a gap 50 is formed between the serration 31 </ b> A and the wall surface 41 of the blade groove 40. In other words, the volume of the fixing 31 is set slightly smaller than the volume of the blade groove 40. The gap 50 is provided in advance at the time of design in order to absorb errors in processing of the blade groove 40 and the rotor blade 30.

The platform 32 in the present embodiment is a substantially rectangular plate-shaped member that is integrally provided on the radially outer side of the fixing 31. Specifically, as shown in FIG. 2, the platform 32 has a substantially parallelogram shape when viewed from the circumferential direction. A radially inner surface of the platform 32 is formed so as to contact the disk 20 on the rotor 1. Furthermore, both sides in the circumferential direction of the platform 32 are formed so as to come into contact with the platform 32 of another adjacent moving blade 30.
The shape and dimensions of the platform 32 are appropriately selected according to the design, and are not limited to the present embodiment.

  The wing part 33 extends radially outward from the platform 32 and has a wing-shaped cross section when viewed from the radial direction. Specifically, as shown in FIG. 2, the wing portion 33 protrudes in a curved shape toward the one side in the circumferential direction on the opposite side of the abdominal portion 33 </ b> A and the abdominal portion 33 </ b> A that is recessed in a curved shape toward the one side in the circumferential direction. And a back portion 33B. The curved surfaces forming the abdomen 33A and the back 33B are continuously connected at both end edges in the direction intersecting the axis O (the chord direction Dh). Of the two end edges in the chord direction Dh, one end edge is formed into a curved surface to form a leading edge 36. An end edge on the opposite side of the leading edge 36 in the chord direction Dh is formed in a pointed shape to form a trailing edge 37.

  In the present embodiment, the shape of the blade portion 33 of the moving blade 30 immediately after manufacture is generally uniform along the moving blade reference line Dp. However, the shape of the wing part 33 is not limited to this mode. For example, a so-called torsional blade may be used in which the blade portion 33 is formed so as to be twisted in advance around the moving blade reference line Dp as it moves from one side to the other side along the moving blade reference line Dp.

  The wing 33 configured in this way is directed toward the leading edge 36 side, ie, the upstream side, and the fluid flows on the trailing edge 37 side along the direction in which the fluid flows in the turbine. It is arranged in the casing of the turbine so as to be directed to the leaving side, that is, the downstream side. In FIG. 2, the upstream side is represented as + Da direction, and the downstream side is represented as -Da direction.

  Further, the abdomen 33A of the wing part 33 generally faces the entire upstream side, and the back part 33B generally faces the entire downstream side. As a result, the fluid flowing from the upstream side collides with the abdomen 33A, so that a force from the abdomen 33A side toward the back 33B side acts on the wing part 33. By this force, the rotor 1 rotates around the axis O. The direction in which the rotor 1 rotates at this time, that is, the direction from the abdominal portion 33A side to the back portion 33B side of the wing portion 33 is referred to as the rotation direction front side, and the opposite side to the rotation direction front side is referred to as the rotation direction rear side. . In FIG. 2, the front side in the rotational direction is represented as + Dc direction, and the rear side in the rotational direction is represented as −Dc direction.

  The shroud 34 is a plate-like member provided on the radially outer side of the wing part 33. More specifically, as shown in FIG. 1, the shroud 34 extends substantially along a plane that intersects the blade reference line Dp. Furthermore, as shown in FIG. 2, when viewed from the outside in the radial direction, the shroud 34 extends in a zigzag shape from the upstream side to the downstream side, and is generally Z-shaped.

  Both upstream and downstream end edges extend in a straight line along the circumferential direction to form an upstream edge 60 and a downstream edge 70, respectively. The upstream edge 60 and the downstream edge 70 face each other in the upstream and downstream directions.

  Of both end edges connecting the upstream end edge 60 and the downstream end edge 70, the front end edge in the rotational direction is a front end edge 80. On the other hand, the edge on the rear side in the rotational direction is the rear edge 90. Both the front side edge 80 and the rear side edge 90 have three sides. Specifically, the front side edge 80 is arranged in order from the upstream side toward the downstream side, the front side first end edge 81, the front side second end edge 82 (front side contact surface 82), and the front side first edge 80. And three end edges 83.

  The front side first end edge 81 is inclined rearward in the rotational direction from the upstream side to the downstream side. Further, the upstream end of the front first end edge 81 and the end of the upstream end edge 60 on the front side in the rotational direction are connected to each other by a curve that curves toward the front side in the rotational direction. The downstream end of the front first end edge 81 is gradually curved toward the front side in the rotational direction to form an arc shape.

  The front-side second end edge 82 is formed in a straight line from the downstream end of the front-side first end edge 81 toward the front side in the rotation direction toward the downstream side. As will be described in detail later, the front-side second end edge 82 is brought into contact with a part of the shroud 34 of the other moving blade 30 adjacent in the circumferential direction on the disk 20, thereby forming a front-side contact surface 82. Yes.

  The front-side third end edge 83 is formed in a straight line shape from the downstream end of the front-side second end edge 82 toward the rear side in the rotation direction toward the downstream side. The downstream end of the front third end edge 83 is connected to the end of the downstream end edge 70 on the front side in the rotational direction.

  Similar to the front side edge 80, the rear side edge 90 is, in order from the upstream side to the downstream side, the rear side first end edge 91, the rear side second edge 92 (the rear side contact surface 92), , A rear side third end edge 93.

  The rear first end edge 91 extends along the same direction as the front first end edge 81. Further, the rear second end edge 92 extends linearly along the same direction as the front second end edge 82. This rear side second end edge 92 is in contact with the front side second end edge 82 of the shroud 34 of the other blade 30 adjacent in the circumferential direction, that is, the front side contact surface 82 over its extending length. Is formed. In other words, of the pair of adjacent blades 30, the front contact surface 82 of the one blade 30 and the rear contact surface 92 of the other blade 30 are in the upstream / downstream direction (axis O direction). ) To be inclined at substantially the same angle.

  The rear third end edge 93 extends along substantially the same direction as the front third end edge 83. The downstream end of the rear third edge 93 is connected to the end of the downstream end edge 70 on the rear side in the rotational direction.

  The rotor blade 30 configured as described above is fixed to a blade groove 40 provided on the disk 20. More specifically, by inserting the fixing 31 in the rotor blade 30 from the opening on one side of the blade groove 40, the serration 31A of the fixing 31 and the teeth 42 of the blade groove 40 are engaged with each other. Thereby, even if a centrifugal force is applied to the moving blade 30 while the rotor 1 is rotating, the rotor 1 is supported without dropping.

  Further, when the rotor 1 is assembled, the rotor 1 is completed by sequentially inserting the plurality of moving blades 30 into the blade grooves 40 along the circumferential direction. In a state of being arranged in the circumferential direction, the pair of adjacent blades 30 abut against each other via the front contact surface 82 and the rear contact surface 92 (see FIG. 2). A portion where the front contact surface 82 and the rear contact surface 92 abut is referred to as a contact portion C.

  Here, as shown in FIG. 2, one point on the three abutting portions C formed by the four moving blades 30 (the shroud 34) arranged sequentially is set to P1, P2 from the rear side in the rotational direction to the front side, respectively. , P3. Further, let L be a dimension from P1 to P2 in a state where the rotor 1 is assembled.

  At this time, in the rotor blade 30 immediately after manufacture, the dimension between the rear contact surface 92 and the front contact surface 82 is set slightly larger than this L. In detail, as shown in FIG. 5, the rear contact surface 92 and the front contact surface 82 are each provided with a margin K. Therefore, when a pair of rotor blades 30 immediately after manufacture are inserted adjacent to each other in the blade groove 40, the cutting edges K of each other interfere with each other so that the pair of rotor blades 30 are aligned along the circumferential direction (rotating direction). In this way, forces in a direction away from each other are applied.

  When the pair of rotor blades 30 in such a state is viewed from the radial direction, as shown in FIG. 2, a force F is applied to the front contact surface 82 and the rear contact surface 92 in a direction perpendicular to the contact surfaces. Join. A force F toward the rear side in the rotational direction is applied to the front contact surface 82 from the upstream side toward the downstream side. A force F as a reaction force is applied to the rear contact surface 92 as it moves from the downstream side toward the upstream side in the rotational direction.

  By the action of these forces F, a rotational moment R directed in the direction indicated by the arrow in FIG. When the blade portion 33 of the moving blade 30 is used as a reference, the rotating blade 30 is twisted by the rotational moment R so that the leading edge 36 is directed forward in the rotational direction and the trailing edge 37 is directed backward in the rotational direction. . The amount of twist at this time is called the pre-twist amount. The pre-twist amount is a physical amount obtained by expressing the rotation amount of the moving blade 30 around a specific reference line in a unit system such as radians.

  Here, in the moving blade 30 according to the present embodiment, the pre-twist amount of the moving blade 30 in a state assembled to the rotor body 10 is determined in advance as a design value (target pre-twist amount). Therefore, when assembling the rotor 1, it is necessary to adjust the shape of the moving blade 30 so that the pre-twist amount of the moving blade 30 matches the target pre-twist amount. This adjustment is performed by cutting the cutting margin K on either the front contact surface 82 or the rear contact surface 92. The pre-twist amount of the moving blade 30 is adjusted according to the amount of cutting at this time, and the moving blade 30 having the target pre-twist amount is obtained.

(Shroud milling amount determination method, rotor manufacturing method)
Next, a method for manufacturing the rotor according to this embodiment will be described. The rotor manufacturing method includes each step of the shroud cutting amount determination method, a cutting step based on the cutting amount determined by this method, and an insertion step.

  First, a method for determining the amount of cutting at the time of cutting on the front contact surface 82 (or the rear contact surface 92) of the shroud 34 will be described. As shown in FIG. 8, the shroud cutting amount determination method according to the present embodiment includes a reference position detection step S1, a spread dimension acquisition step S2, and a cutting amount determination step S3. In general, in this method, the step of determining the amount of cutting of the shroud 34 of one moving blade 30 using a pair of adjacent moving blades 30 is sequentially performed on all the moving blades 30.

First, the reference position detection step S1 will be described with reference to FIGS. In the reference position detection step S <b> 1, the reference position of the moving blade 30 is detected by inserting only one moving blade 30 into the blade groove 40. As described above, the gap 50 is formed in the circumferential direction between the fixing 31 of the rotor blade 30 and the blade groove 40. Due to the gap 50, the moving blade 30 can slightly swing along the circumferential direction. First, the magnitude of this runout is measured. Specifically, when the moving blade 30 is moved along the circumferential direction, the amount of deflection at an arbitrary point on the shroud 34 (for example, the point P1 in the contact portion C described above) is measured using a measuring device such as a dial gauge. Measure with When this deflection amount is T1, a value obtained by multiplying T1 by 0.5, that is, a position where 0.5T1 is obtained is set as a reference position of the moving blade 30. Specifically, after measuring the shake amount T1 with the measuring device, 0.5T1 is calculated and recorded based on this T1. After the detection of the reference position is completed, the moving blade 30 is removed from the blade groove 40.
The reference position is a position where the main axis O of the moving blade 30 passes the above-described moving blade reference line Dp.

Subsequently, by performing the same process as described above for the other moving blades 30 adjacent to the above-described moving blades 30, the shake amount T2 at the reference position of the moving blades 30 is detected, and 0.5T2 is calculated based on this. calculate. After the detection of the reference position is completed, the moving blade 30 is removed from the blade groove 40. Thus, the reference position detection step S1 is completed.
In the present embodiment, the example in which the reference position of the moving blade 30 on the front side in the rotation direction is sequentially detected after the moving blade 30 on the rear side in the rotation direction has been described. However, the reference position of the moving blade 30 on the rear side in the rotation direction may be sequentially detected after the moving blade 30 on the front side in the rotation direction.

  Next, a spread dimension acquisition step S2 is performed. In the spread dimension acquisition step S2, a pair of moving blades 30 that have finished the above-described reference position detection step S1 are first inserted into adjacent blade grooves 40, respectively. At this time, it inserts in the blade groove | channel 40 so that contact surfaces (front side contact surface 82 and back side contact surface 92) in the shroud 34 of each moving blade 30 may contact. As described above, the cutting margins K are provided in advance on the respective contact surfaces. Therefore, when a pair of blades 30 are inserted together, the blades 30 are separated from each other along the circumferential direction. Move slightly. At the same time, the rotor blade 30 is in a state of being twisted as described above.

  Next, the circumferential dimension of the shroud 34 of the pair of blades 30 in such a state is measured. Specifically, as shown in FIG. 5, the dimension between the rear side contact surface 92 of the moving blade 30 on one side (the rear side in the rotation direction) and the front side contact surface 82 of the moving blade 30 on the other side is set. Measure using a measuring device such as a dial gauge. The value at this time is defined as a circumferentially measured value L. In actual measurement, for the sake of accuracy, the circumferential dimension L1 of the moving blade 30 on one side and the circumferential dimension L2 of the moving blade on the other side are separately measured, and then L1 and L2 are measured. It is desirable to set it as the circumferential direction actual measurement value L (= L1 + L2).

Next, the spread dimension H is calculated by subtracting the sum of the deflection amounts 0.5T1 and 0.5T2 of the moving blades 30 at the reference position from the circumferential direction actual measurement value L. Specifically, the calculation shown in the following equation (1) is performed.
H = L- (0.5T1 + 0.5T2) (1)
As shown in the equation (1), the spread dimension H is the difference between the circumferential dimension of the pair of shrouds 34 and the circumferentially measured value L when it is assumed that the pair of moving blades 30 are both at the reference position. Represents.

  Further, the spread dimension H has a correlation as shown in FIG. 7 with the above-described pretwist amount (hereinafter referred to as θ). More specifically, as the spreading dimension H increases, the force F applied to the contact surfaces (the front contact surface 82 and the rear contact surface 92) of the rotor blade 30 increases. To increase. Thus, the spread dimension acquisition step S2 is completed.

Subsequently, a shaving amount determination step S3 is performed. In the cutting amount determination step S3, the cutting amount G of the shroud 34 is determined based on the spread amount H and the correlation between H and the pretwist amount θ shown in FIG. In this embodiment, the pre-twist amount θ is adjusted by cutting the side of the blade portion 33 of the rotor blade 30 facing the back portion 33B, that is, the front contact surface 82. Therefore, the cutting amount G represents the cutting amount when cutting the front contact surface 82.
Specifically, referring to the correlation graph between the spread amount H and the pretwist amount θ shown in FIG. 7, the spread amount when the design pretwist amount (hereinafter referred to as θp) is taken (hereinafter, the design spread amount Hp). Ask for. Next, by obtaining the difference between the spread amount H that is an actual measurement value and the design spread amount Hp, the shaving amount G is calculated (see equation (2)). Thus, the cutting amount determination step S3 is completed.
G = H−Hp (2)

This cutting amount determination method is sequentially performed for all the moving blades 30 over the entire circumference of the rotor 1. Specifically, when the four moving blades 30 adjacent in the circumferential direction are respectively the first moving blade, the second moving blade, the third moving blade, and the fourth moving blade, the first moving blade and the first moving blade Each step of the cutting amount determination method is performed for the two blades. Next, the amount of cutting is determined in the same manner for the second and third rotor blades. Further, the amount of cutting is determined for the third and fourth rotor blades. In this way, the same process is repeated for all the pair of moving blades 30 adjacent to each other.
Thus, all the steps of the shroud cutting amount determination method according to the present embodiment are completed.

  Next, as shown in FIG. 9, based on the cutting amount G determined in the cutting amount determination step S3, the cutting step S4 for cutting the front contact surface 82, and the rotor blade 30 with the contact surface cut is a blade. By performing the insertion step S5 of sequentially inserting into the groove 40, all the steps of the rotor manufacturing method according to the present embodiment are completed.

  As described above, according to the above-described shroud shaving amount determination method, the spread dimension H in the circumferential direction in the shroud 34 is acquired in the spread dimension acquisition step S2, and the spread dimension H and the pre-size are determined in the scraping amount determination step S3. The contact surface shaving amount G is determined based on the correlation with the twist amount. That is, the amount of cutting of the contact surface of the shroud 34 that is the cutting target is determined based on the dimension of the shroud 34 that is also the cutting target in the circumferential direction. Thereby, the error contained in the amount G of cutting can be reduced compared with the case where the amount G of cutting is determined based on the expansion dimension of the part different from the shroud 34 which is a cutting object.

  Further, according to this method, the reference positions of the pair of blades 30 are compared with the circumferential dimensions of the pair of shrouds 34 when the pair of blades 30 are inserted so that the contact surfaces are in contact with each other. The spread dimension can be acquired only by doing. Thereby, the grinding amount G of the contact surface can be determined easily and precisely.

  In addition, according to this method, it is possible to easily determine the shaving amount G for all the moving blades 30 only by repeating the same process over the entire circumference of the disk 20.

  In addition, according to the above-described rotor manufacturing method, the rotor blades 30 whose contact surfaces are appropriately cut by the cutting amount determination step S3 and the cutting step S4 are collectively inserted into the blade groove 40 in the insertion step. Can do. That is, when inserting the rotor blade 30 into the blade groove 40, the rotor 1 can be easily manufactured without causing rework or repetition of other processes.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

DESCRIPTION OF SYMBOLS 1 ... Rotor 10 ... Rotor main body 20 ... Disc 30 ... Moving blade 31 ... Fixing 31A ... Serration 32 ... Platform 33 ... Wing 33A ... Abdomen 33B ... Back 34 ... Shroud 36 ... Leading edge 37 ... Trailing edge 40 ... Blade groove 41 ... Wall 42 ... Tooth 50 ... Gap 60 ... Upstream side edge 70 ... Downstream side edge 80 ... Front side edge 81 ... Front side first edge 82 ... Front side second edge 82 ... Front side contact surface 83 ... Front third edge 90 ... Rear edge 91 ... Rear first edge 92 ... Rear second edge 92 ... Rear contact surface 93 ... Rear third edge C ... Abutting portion Dh ... Wing String direction Dp ... Rotor blade reference line O ... Axis

Claims (4)

The pair of blades are inserted into each of the blade grooves of the disk provided with a pair of adjacent blades so that the contact surfaces of the shrouds are in contact with each other. A spread dimension acquisition step of acquiring a spread dimension in the direction;
Based on the spread dimension and the correlation between the spread dimension and the pre-twist amount of the rotor blade obtained in advance, a pair of shrouds is set so that the pre-twist amount of the pair of rotor blades is an arbitrary value. A cutting amount determination step for determining a cutting amount of one of the contact surfaces that are in contact with each other;
A method for determining the amount of shroud shaving. Only one of the pair of adjacent blades is inserted into the blade groove of the disk where the blade is provided to detect the reference position of the one blade, and the pair of adjacent blades A reference position detection step of detecting only the other moving blade of the moving blades into the blade groove of the disk on which the moving blade is provided, and detecting the reference position of the other moving blade;
Further comprising
The spread dimension acquisition step detects the circumferential dimension of the pair of shrouds when the pair of blades are inserted so that the contact surfaces of the shrouds contact each other, and the detected circumferential dimension The shroud cutting amount determination method according to claim 1, wherein the spread dimension is obtained by comparing the reference position of the one moving blade and the reference position of the other moving blade. The shroud cutting amount determination method according to claim 2, wherein the spread dimension acquisition step, the reference position detection step, and the cutting amount determination step are sequentially performed over the entire circumference of the disk for a pair of adjacent moving blades. A rotor manufacturing method using the shroud cutting amount determination method according to any one of claims 1 to 3,
A cutting step of cutting the contact surface of the shroud based on the cutting amount determined in the cutting amount determination step;
An insertion step of sequentially inserting the blades with the contact surfaces cut into the blade grooves;
The manufacturing method of the rotor containing this.

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