JP5725849B2 - fixing jig - Google Patents

Description

  The present invention relates to a fixing jig for fixing a moving blade when measuring the natural frequency of the moving blade attached to a rotating machine.

  Conventionally, when measuring the natural frequency of a moving blade, as a method of fixing the moving blade, the blade root of the moving blade is engaged with the blade groove portion of the turbine disk, and the blade root is pushed up by a hydraulic jack. There is known a method of fixing the blade to the blade groove (for example, see Patent Document 1). The actual blade static vibration test is performed by tapping the rotor blade fixed by this fixing method.

JP 59-110804 A

  Here, when the natural frequency of the rotor blade is measured with the rotor blade fixed to the turbine disk, the vibration mode of the rotor blade and the vibration mode of the turbine disk are coupled. It becomes difficult to measure accurately.

  For this reason, there is a method of measuring the natural frequency of the moving blade by fixing the moving blade to the base. In this method, the rotor blade is fixed to the base, and a load corresponding to a centrifugal force is applied to the rotor blade. Then, the rotor blade is tapped (tapped) and the vibration of the rotor blade is measured. The natural frequency is measured. In this case, since the mass of the base can be increased, the natural frequency of the rotor blade can be suitably measured. At this time, since it is necessary to fix the rotor blade to the base, a blade groove for attaching the rotor blade is usually formed on the base, and the rotor blade is attached to the blade groove.

  However, since the load is applied to the blade during measurement of the natural frequency of the blade, a load is applied to the blade groove, and as a result, the number of measurements increases, so that Will occur, and the function as a blade groove will decline. The base may be made of a material having high rigidity, but the material cost is increased because the material having high rigidity is expensive.

  Accordingly, an object of the present invention is to provide a highly versatile fixing jig that can maintain the function of the blade groove even when the number of measurements is increased with an inexpensive configuration.

  The fixing jig of the present invention is a fixing jig for fixing a moving blade at the time of measuring the natural frequency of the moving blade attached to the rotating machine, and is fixed to the base portion and the base portion and engaged with the moving blade. A blade groove mounting portion provided with a blade groove to be pressed, and a pressing portion for fixing the blade to the blade groove mounting portion by pressing the blade in the centrifugal force direction in a state where the blade is engaged with the blade groove. It is characterized by comprising.

  According to this configuration, the blade groove mounting portion can be provided between the base portion and the moving blade, and the blade groove can be provided in the blade groove mounting portion. For this reason, a moving blade can be fixed to a base part via a blade groove attaching part. At this time, if the blade groove mounting portion is made of a material having high rigidity, it can be made cheaper than the case where the base portion is made of a material having high rigidity. The function can be maintained. In addition, depending on the type of moving blade to be measured, the base portion can be shared by appropriately replacing different types of blade groove mounting portions, so that the versatility can be improved.

  In this case, the base portion is formed with an accommodation groove having a regulating surface that accommodates the blade groove attachment portion and restricts the blade groove attachment portion, and the moving blade is pressed in the centrifugal force direction by the pressing portion. It is preferable that the attachment portion is fixed in contact with the regulation surface of the accommodation groove.

  According to this configuration, when the pressing portion presses the moving blade, the moving blade can be fixed to the blade groove mounting portion, and the blade groove mounting portion can be fixed to the base portion.

  In this case, it is preferable that the housing groove has a dovetail shape in which the regulation surface is an inclined surface, and the blade groove mounting portion has a contact surface that contacts the regulation surface.

  According to this configuration, since the receiving groove can be formed in a dovetail shape, when the moving blade is pressed by the pressing portion, the blade groove mounting portion is pressed by the receiving groove. At this time, since the contact area between the receiving groove of the base portion and the blade groove mounting portion can be widened, the surface pressure of the blade groove mounting portion with respect to the base portion can be reduced, and deformation of the base portion can be suppressed. Can do.

  In this case, it is preferable to further include a spacer provided so as to fill a gap between the receiving groove of the base portion and the blade groove mounting portion.

  According to this configuration, the spacer can fill the gap between the housing groove and the blade groove mounting portion, and can be in close contact with the housing groove and the blade groove mounting portion. Thereby, it becomes possible to suppress the play between the accommodation groove and the blade groove mounting portion.

  In this case, the blade groove mounting portion is preferably fastened to the base portion using a fastening member.

  According to this configuration, the blade groove mounting portion can be fixed to the base portion with a simple configuration.

  According to the fixing jig of the present invention, it is possible to provide a versatile tool that can maintain the function of the blade groove even when the number of measurements is increased with an inexpensive configuration.

FIG. 1 is a schematic configuration diagram schematically illustrating a fixing jig according to the first embodiment. FIG. 2 is a plan view schematically illustrating the fixing jig according to the first embodiment. FIG. 3 is a schematic configuration diagram schematically illustrating a fixing jig according to a modification of the first embodiment. FIG. 4 is a schematic configuration diagram schematically illustrating the fixing jig according to the second embodiment. FIG. 5 is a schematic configuration diagram schematically illustrating the fixing jig according to the third embodiment.

  Hereinafter, the fixing jig of the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the following examples. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  The fixing jig according to the first embodiment is for fixing a moving blade when measuring the natural frequency of the moving blade provided in a rotary machine such as a turbine or a pump. When the rotating machine is operated, the moving blade attached to the rotating machine is loaded in the centrifugal force direction. For this reason, in the fixing jig, a load corresponding to a centrifugal force is applied to the moving blade in the centrifugal force direction. The moving blades measure their natural frequencies while being removed one by one from the fixing jig. Hereinafter, the fixing jig will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a schematic configuration diagram schematically illustrating a fixing jig according to the first embodiment, and FIG. 2 is a plan view schematically illustrating the fixing jig according to the first embodiment. As shown in FIG. 1, the moving blade 5 attached to the fixing jig 1 includes a blade portion 6 and a blade root portion 7, and the blade root portion 7 is fixed to the fixing jig 1. The centrifugal force direction of the load applied to the moving blade 5 is the upper side in the vertical direction. The blade root portion 7 has a pair of engaging portions 7 a protruding outward in the horizontal direction, and the pair of engaging portions 7 a engages with the fixing jig 1 and is fixed. In the first embodiment, the blade root portion 7 has the above-described shape. However, the shape is not limited to this, and may be, for example, a tree shape or any shape as long as it can be attached.

  As shown in FIGS. 1 and 2, the fixing jig 1 is fixed to the base part 11 joined on the surface plate 10, the blade groove attachment part 12 fixed to the base part 11, and the blade groove attachment part 12. And a hydraulic jack (pressing part) 13 for pressing the moving blade 5.

  The base portion 11 is formed in a block shape and joined to the surface plate 10 by welding. The base portion 11 is made of an inexpensive material as compared with the blade groove mounting portion 12. An accommodation space 20 for accommodating the hydraulic jack 13 is formed on the lower side of the base portion 11 in the vertical direction (the surface plate 10 side). The accommodation space 20 is provided so as to extend through the central portion of the base portion 11 on the lower side in the front-rear direction of FIG. In addition, an accommodation groove 21 for accommodating the blade groove mounting portion 12 is formed in the central portion of the base portion 11 on the upper side in the vertical direction (the moving blade 5 side). That is, the accommodation groove 21 is provided on the upper side of the accommodation space 20. The housing groove 21 is provided so as to extend through the center portion of the upper base portion 11 in the front-rear direction of FIG. Further, a through-hole 22 having a circular cross section is formed through the base portion 11 so as to communicate the accommodation space 20 and the accommodation groove 21, and the piston 32 of the hydraulic jack 13 is inserted into the through-hole 22.

  The accommodation groove 21 is formed in a dovetail shape, the groove width on the lower side in the vertical direction is wide, and the groove width becomes narrower toward the upper side in the vertical direction. That is, the accommodation groove 21 has a pair of inclined surfaces that incline from the outside to the inside from the lower side in the vertical direction toward the upper side on the front side in FIG. The pair of inclined surfaces constitute a pair of regulating surfaces 21a that regulate the upward movement of the blade groove mounting portion 12 in the vertical direction.

  Moreover, the base part 11 is provided with a stopper 23 for regulating the position of the blade groove mounting part 12 accommodated in the accommodation groove 21 (see FIG. 2). The stopper 23 is disposed so as to span the upper surface on one side (right side in the drawing) in the vertical direction of the base portion 11 and the upper surface on the other side (left side in the drawing) across the accommodation groove 21. A part of the stopper 23 protrudes into the receiving groove 21, and the protruding portion restricts the position of the blade groove mounting portion 12 in the extending direction of the receiving groove 21.

  The blade groove mounting portion 12 is formed in a trapezoidal cross section and can be received in the receiving groove 21. The blade groove mounting portion 12 is made of an expensive material as compared with the base portion 11. The blade groove mounting portion 12 is made of the same material as the disk (rotary body) to which the moving blade 5 is mounted in the rotary machine, and is a material having higher rigidity than the base portion 11. The blade groove mounting portion 12 has a pair of contact surfaces 12 a that contact the pair of regulating surfaces 21 a of the housing groove 21. The pair of contact surfaces 12a and the pair of regulating surfaces 21a have a complementary shape. That is, the pair of contact surfaces 12a are inclined from the outside to the inside from the lower side to the upper side in the vertical direction.

  A blade groove 27 for attaching the blade root portion 7 of the moving blade 5 is formed in the central portion on the upper side in the vertical direction of the blade groove mounting portion 12. The blade groove 27 is provided so as to extend through the center portion of the blade groove mounting portion 12 in the front-rear direction of FIG. On the lower side in the vertical direction of the blade groove mounting portion 12, an insertion port 28 having a circular cross section that communicates the bottom surface of the blade groove mounting portion 12 and the blade groove 27 is formed so as to pass through. The piston 32 is inserted.

  The blade groove 27 has a shape complementary to the blade root portion 7 of the rotor blade 5, and a pair of locking portions 27 a that are locked to the pair of engaging portions 7 a are formed. The pair of locking portions 27 a Projects inward in the direction. And this pair of latching | locking part 27a can fix the moving blade 5 by striking against a pair of engaging part 7a which is pressed and moves to the upper side of a perpendicular direction. The blade groove 27 is not limited to the above configuration, and may be any configuration that can be fixed by pressing the moving blade 5.

  As shown in FIG. 2, the blade groove mounting portion 12 configured as described above is inserted from the extending direction of the receiving groove 21 and is abutted against the stopper 23, thereby restricting the position in the extending direction. . Note that a plurality of blade groove mounting portions 12 are prepared according to the shape of the blade root portion 7 of the moving blade 5, that is, according to the shape of the blade groove 27, and the base portion according to the moving blade 5 to be measured. 11 is appropriately changed.

  The hydraulic jack 13 includes a jack body 31 and a piston 32 that protrudes from the jack body 31. The jack body 31 is housed in the housing space 20 of the base portion 11. The piston 32 has an axial direction in the vertical direction, and is inserted through the through-hole 22 of the base portion 11 and the insertion port 28 of the blade groove mounting portion 12. The piston 32 can be pressed with the end face on the upper side in the vertical direction coming into contact with the blade root portion 7 of the moving blade 5.

  Therefore, when attaching the moving blade 5 to the fixing jig 1, the blade groove mounting portion 12 corresponding to the moving blade 5 is inserted into the receiving groove 21 from the extending direction of the receiving groove 21 and abuts against the stopper 23. Position. The insertion slot 28 of the positioned blade groove mounting portion 12 coincides with the through hole 22 of the base portion 11 in the vertical direction. Thereafter, the rotor blade 5 is inserted into the blade groove 27 from the extending direction of the blade groove 27 and is positioned immediately above the insertion port 28. Then, by pushing up the piston 32 upward in the vertical direction by the hydraulic jack 13, the piston 32 passes through the through hole 22 and the insertion port 28, hits the blade root portion 7 of the moving blade 5, and moves the moving blade 5. Push up.

  When the moving blade 5 is pushed up, the pair of engaging portions 7a of the moving blade 5 abuts against the pair of engaging portions 27a of the blade groove mounting portion 12, whereby the blade groove mounting portion 12 moves upward in the vertical direction. Pushed up. When the blade groove mounting portion 12 is pushed up, the pair of contact surfaces 12a of the blade groove mounting portion 12 comes into contact with the pair of regulating surfaces 21a of the receiving groove 21, and the position of the blade groove mounting portion 12 is restricted. As a result, the blade groove mounting portion 12 is fixed to the base portion 11, and the rotor blade 5 is fixed to the blade groove mounting portion 12.

  As described above, according to the fixing jig 1 of the first embodiment, the blade groove mounting portion 12 can be provided between the base portion 11 and the rotor blade 5, and the blade groove 27 can be provided in the blade groove mounting portion 12. . For this reason, the moving blade 5 can be fixed to the base portion 11 via the blade groove mounting portion 12. At this time, since the blade groove mounting portion 12 is made of a material having high rigidity, the shape of the blade groove 27 is preferably maintained even when the number of times of measurement of the natural frequency of the rotor blade 5 is increased. And the function of the blade groove 27 can be maintained. Moreover, since the base part 11 can be comprised with an inexpensive material, it can be made cheap compared with the case where the base part 11 is comprised with an expensive material with high rigidity. In addition, since the base 11 can be shared by appropriately replacing different types of blade groove mounting portions 12 according to the type of the moving blade 5 to be measured, it can be highly versatile. .

  Further, since the accommodation groove 21 can be formed in a dovetail shape and the blade root portion 7 of the moving blade 5 can be formed in a trapezoidal cross section, the moving blade 5 is pressed upward in the vertical direction, so that the moving blade 5 is moved into the blade groove. It can be fixed to the mounting portion 12, and the blade groove mounting portion 12 can be fixed to the base portion 11. At this time, since the contact area between the regulation surface 21a of the base portion 11 and the contact surface 12a of the blade groove mounting portion 12 can be increased, the surface pressure of the blade groove mounting portion 12 against the base portion 11 can be reduced. Thereby, the deformation | transformation of the base part 11 can be suppressed.

  The blade groove mounting portion 12 and the accommodation groove 21 may be configured as shown in FIG. FIG. 3 is a schematic configuration diagram schematically illustrating a fixing jig according to a modification of the first embodiment. In the fixing jig 1 of Modification 1, the shape of the blade groove mounting portion 12 is different from that of the first embodiment, and the shape of the receiving groove 21 is also different according to the shape of the blade groove mounting portion 12. Specifically, the blade groove mounting portion 12 has a convex section, and the receiving groove 21 has a convex section. That is, the pair of contact surfaces 12a of the blade groove mounting portion 12 is a horizontal plane, and the pair of regulation surfaces 21a of the accommodation groove 21 is also a horizontal plane. Even in such a configuration, the fixing jig 1 fixes the blade groove mounting portion 12 to the base portion 11 and pushes the blade 5 to the blade groove mounting portion 12 by pushing up the blade 5 by the hydraulic jack 13. Can be fixed.

  Then, with reference to FIG. 4, the fixing jig 40 which concerns on Example 2 is demonstrated. FIG. 4 is a schematic configuration diagram schematically illustrating the fixing jig according to the second embodiment. Only different parts will be described in order to avoid duplicate descriptions. In the fixing jig 40 according to the second embodiment, a spacer 41 is provided between the base portion 11 and the blade groove mounting portion 12.

  The spacer 41 is configured to be deformable by being pressed by the hydraulic jack 13, and is provided between the pair of regulating surfaces 21 a of the housing groove 21 and the pair of contact surfaces 12 a of the blade groove mounting portion 12. For this reason, when the moving blade 5 is pressed by the hydraulic jack 13, the spacer 41 provided between the regulation surface 21a and the contact surface 12a is deformed, and is closely attached to the regulation surface 21a and the contact surface 12a. To do. Thereby, the spacer 41 can fill the gap between the regulation surface 21a and the contact surface 12a.

  As described above, according to the fixing jig 40 of the second embodiment, since the spacer 41 can fill the gap between the receiving groove 21 and the blade groove mounting portion 12, the receiving groove 21 and the blade groove mounting portion. It becomes possible to suppress the rattling between the two.

  Next, the fixing jig 50 according to the third embodiment will be described with reference to FIG. FIG. 5 is a schematic configuration diagram schematically illustrating the fixing jig according to the third embodiment. Only different parts will be described in order to avoid duplicate descriptions. In the fixing jig 50 of the third embodiment, the base portion 51 and the blade groove mounting portion 52 are fastened and fixed by a fastening member 53. Hereinafter, the fixing jig 50 of Example 3 will be specifically described.

  The base portion 51 has a configuration in which the accommodation groove 21 of the base portion 11 of the first embodiment is omitted. That is, the base 51 is formed in a block shape, and the hydraulic jack 13 is accommodated on the lower side in the vertical direction. As in the first embodiment, the base portion 51 is formed with a through-hole 22 formed so as to penetrate in the vertical direction, and the piston 32 of the hydraulic jack 13 is inserted therethrough. The blade groove mounting portion 52 is formed in a block shape and is configured to be placed on the upper surface of the base portion 51. In the blade groove mounting portion 52, as in the first embodiment, a blade groove 27 for mounting the blade root portion 7 of the moving blade 5 is formed in the central portion on the upper side in the vertical direction. The fastening member 53 is a so-called fastening bolt, and fastens and fixes the blade groove mounting portion 52 to the base portion 51. The fastening member 53 is fastened to the top surface side of the base portion 51 from the top surface of the blade groove mounting portion 52 through the blade groove mounting portion 52.

  As described above, according to the fixing jig 50 of the third embodiment, the blade groove mounting portion 52 can be easily fixed to the base portion 51 by the fastening member 53. Moreover, since it is not necessary to perform a complicated process with respect to the base part 51 and the blade groove attaching part 52, a process cost can be suppressed.

  As described above, the fixing jig according to the present invention is useful when fixing the moving blade attached to the rotating machine, and is particularly suitable for measuring the natural frequency of the moving blade.

DESCRIPTION OF SYMBOLS 1 Fixing jig 5 Moving blade 6 Blade part 7 Blade root part 10 Surface plate 11 Base part 12 Blade groove attaching part 12a Contact surface 13 Hydraulic jack 20 Housing space 21 Housing groove 21a Restricting surface 22 Through-hole 23 Stopper 27 Blade groove 28 Insertion Port 31 Jack body 32 Piston 40 Fixing jig 41 Spacer 50 Fixing jig 51 Base part 52 Blade groove attaching part 53 Fastening member

Claims (5)

A fixing jig for fixing the moving blade when measuring the natural frequency of the moving blade attached to the rotating machine,
The foundation,
A blade groove mounting portion fixed to the base portion and provided with a blade groove that engages with the moving blade, and
A pressing portion for fixing the moving blade to the blade groove mounting portion by pressing the moving blade in the centrifugal force direction in a state where the moving blade is engaged with the blade groove ;
The base portion is formed with an accommodation groove having a regulating surface for accommodating the blade groove attachment portion and restricting the blade groove attachment portion,
The fixing jig is characterized in that the blade groove mounting portion is fixed in contact with the regulation surface of the receiving groove when the moving blade is pressed in the centrifugal force direction by the pressing portion . The accommodating groove, the regulating surface has a dovetail groove shape which is inclined surface, the blade groove attachment portion according to claim 1, characterized in that it has an abutment surface which abuts on the regulating surface The fixing jig described in 1. Fixture according to claim 1 or 2, characterized in that the spacer that is provided so as to bridge the gap between the accommodation groove and the blade groove mounting portion of the base portion, further comprising.   The said blade groove attaching part is comprised with the material similar to the rotary body of the said rotary machine to which the said moving blade is attached, The rigidity is high compared with the said base part, The any one of Claim 1 to 3 characterized by the above-mentioned. The fixing jig according to item 1.   A stopper that regulates the position of the blade groove mounting portion that is disposed so as to span the upper surface on one side and the upper surface on the other side of the base portion across the housing groove, The fixing jig according to any one of claims 1 to 4, further comprising a fixing jig.

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