JP5393524B2 - Turbine blade - Google Patents

Description

  The present invention relates to a turbine rotor blade, and more particularly to a turbine rotor blade having a fork-type blade implantation portion.

  Conventionally, a fork-type blade implantation portion (blade fork) of a moving blade engages with a fork of a disk and is fixed by inserting pins into a plurality of pin holes. In this type of turbine, stress is applied to the pin hole as the turbine rotates, and therefore, inspection of the pin hole is regarded as important in order to confirm the reliability of the moving blade in service.

  As a technique for realizing non-decomposition inspection, application of ultrasonic testing (UT) has been studied. In the ultrasonic flaw detection test, an ultrasonic wave is reflected within an inspection object to reach a defect, and a reflected wave from the defect is received. Here, in order to facilitate an ultrasonic flaw detection test, a moving blade having no step is known in order to facilitate the incidence of ultrasonic waves (see, for example, Patent Document 1).

JP 2009-103015 A

  The turbine rotor blade described in Patent Document 1 relates to a rotor blade having no step. However, generally used blades have one or two steps in the blade implantation part (blade fork).

  Generally, in the ultrasonic flaw detection test, the range of the ultrasonic refraction angle at which the reflection efficiency is high is about 35 to 55 °. When performing an ultrasonic flaw detection test on a moving blade having a step in this refraction angle range, the stress is In some cases, ultrasonic waves cannot enter the pin hole. On the other hand, if a region where the refraction angle is low and the reflection efficiency is used, an ultrasonic wave can be incident on the pin hole where stress is applied, but the intensity of the received wave is lowered and the ultrasonic flaw detection test becomes difficult.

  An object of the present invention is to provide a turbine blade capable of improving the detection sensitivity of an ultrasonic flaw detection test even for a blade having a step.

(1) In order to achieve the above object, the present invention is a turbine rotor blade having a fork-type blade implantation portion, which is located at an end portion in the rotational axis direction among a plurality of forks, and is subjected to an ultrasonic flaw detection test. An outer fork having two steps in the radial cross section of the turbine, and a blade attachment portion integrally attached to the blade implantation portion on the radially outer side of the rotating shaft of the blade implantation portion, and the blade and a protruding portion protruding toward the rotation axis direction from the outer end surface of the rotation axis of the outer fork at the end of the rotation axis direction of the mounting portion, the width of the overhang portion and w0, the first step The fork width is w1, the fork width above the second step is w2, the fork width below the second step is w3, the fork length is L1, and the inspection position of the two circumferential fork end faces Fork end surface on one side in the circumferential direction closer to the The distance from the inspection position is Ld, the distance between the fork end surface on the other circumferential side and the ultrasonic incident point is Ls, the height of the overhang is h0, and the fork height on the first step is h1. and then, the height of the first step and hd1, fork height above the second step and h2, the second step height and hd2, from the second step to the inspection position height h3, when the total height H is h0 + h1 + hd1 + h2 + h2 + h3, the total width W is w0 + w1 + (w1 + w2) ÷ 2 + w2 + (w2 + w3) ÷ 2 + w3, and the total length L is L1−Ls−Ld tan ⁻¹ ((L ² + H ² ) ^1/2 ÷ W) ≦ 55 °.

  With this configuration, the detection sensitivity of the ultrasonic flaw detection test can be improved even for a moving blade having a step.

(2) In the above (1), preferably, the ratio between the total height H, the total width W, and the total length L is H: W: L = 1: 0.78-2. 58: 0 to more than 2.58 or less, which was in the range of.

(3) In order to achieve the above object, the present invention is a turbine rotor blade having a fork-type blade implantation portion, and is located at an end portion in the rotation axis direction among a plurality of forks, An outer fork having two steps in the turbine radial cross section to be subjected to a flaw detection test, and a blade attachment portion attached integrally with the blade implantation portion on the outer side in the radial direction of the rotation shaft of the blade implantation portion; A projecting portion projecting from the outer end surface of the outer fork in the rotational axis direction toward the rotational axis direction at the end in the rotational axis direction of the blade attachment portion, and the width of the projecting portion is w0. The fork width on the step is w1, the fork width on the second step is w2, the fork width below the second step is w3, the fork length is L1, and there are two circumferential fork end faces. Fork end face on one side in the circumferential direction closer to the inspection position The distance from the inspection position is Ld, the distance between the fork end surface on the other circumferential side and the ultrasonic incident point is Ls, the height of the overhang is h0, and the fork height on the first step is and h1, the height of the first step and hd1, fork height above the second step and h2, the second step height and hd2, from the second step to the inspection position height H3, the total height H is h0 + h1 + hd1 + h2 + h2 + h3, the total width W ′ is w0 + w1 + (w1 + w2) ÷ 2 + w2 + (w2 + w3) ÷ 2 + w3 + w3, and the total length L is L1−Ls−Ld The structure is such that ° ≦ tan ⁻¹ ((L ² + H ² ) ^1/2 ÷ W ′) ≦ 55 °.

  With this configuration, the detection sensitivity of the ultrasonic flaw detection test can be improved even for a moving blade having a step.

(4) In the above (3), preferably, the ratio between the total height H, the total width W ′, and the total length L is H: W ′: L = 1: 0.78˜ The range of 2.58: 0 to 2.58 or less .

(5) Further, in order to achieve the above object, the present invention is a turbine blade having a fork-type blade implantation portion, and is located at an end portion in the rotation axis direction among a plurality of forks, An outer fork having a step in the turbine radial direction cross-section to be subjected to a flaw detection test, a blade attachment portion attached integrally with the blade implantation portion on the outside in the radial direction of the rotation shaft of the blade implantation portion, A projecting portion projecting from the outer end surface of the outer fork in the rotational axis direction toward the rotational axis direction at the end in the rotational axis direction of the blade attachment portion, and the width of the projecting portion is w0. The fork width on the step is w1, the fork width below the first step is w2, the fork length is L1, and one of the two fork end faces in the circumferential direction closer to the inspection position. The distance between the end surface and the inspection position is Ld, and the circumferential direction The distance between the other fork end surface and the ultrasonic incident point is Ls, the height of the overhang is h0, the fork height on the first step is h1, and the height of the first step is hd1. and then, from the first step to the inspection position height 'a total h2 of height h0 + h1 + hd1 + h2' h2 is the sum W2 of width w0 + w1 + (w1 + w2 ) ÷ 2 + w2, the total L of the length When L1−Ls−Ld, 35 ° ≦ tan ⁻¹ ((L ² + H2 ² ) ^1/2 ÷ W2) ≦ 55 °.

  With this configuration, the detection sensitivity of the ultrasonic flaw detection test can be improved even for a moving blade having a step.

(6) In the above (5), preferably, the ratio between the total height H2, the total width W2, and the total length L is set to H2: W2: L = 1: 0.78-2. 58: 0 to more than 2.58 or less, which was in the range of.

(7) Further, in order to achieve the above object, the present invention is a turbine rotor blade having a fork-type blade implantation portion, which is located at an end portion in the rotation axis direction among a plurality of forks, and An outer fork having a step in the turbine radial direction cross-section to be subjected to a flaw detection test, a blade attachment portion attached integrally with the blade implantation portion on the outside in the radial direction of the rotation shaft of the blade implantation portion, A projecting portion projecting from the outer end surface of the outer fork in the rotational axis direction toward the rotational axis direction at the end in the rotational axis direction of the blade attachment portion, and the width of the projecting portion is w0. The fork width on the step is w1, the fork width below the first step is w2, the fork length is L1, and one of the two fork end faces in the circumferential direction closer to the inspection position. The distance between the end surface and the inspection position is Ld, and the circumferential direction The distance between the other fork end surface and the ultrasonic incident point is Ls, the height of the overhang is h0, the fork height on the first step is h1, and the height of the first step is hd1. and then, from the first step to the inspection position height 'a total h2 of height h0 + h1 + hd1 + h2' h2 is the sum W2 'is w0 + w1 + (w1 + w2 ) ÷ 2 + w2 + w2 width, total length L When L1−Ls−Ld, 35 ° ≦ tan ⁻¹ ((L ² + H ² ) ^1/2 ÷ W2 ′) ≦ 55 °.

  With this configuration, the detection sensitivity of the ultrasonic flaw detection test can be improved even for a moving blade having a step.

(8) In the above (7), preferably, the ratio between the total height H2, the total width W2 ′, and the total length L is H2: W2 ′: L = 1: 0.78˜ The range of 2.58: 0 to 2.58 or less .

ADVANTAGE OF THE INVENTION According to this invention, the detection sensitivity of an ultrasonic flaw detection test can be improved also to the moving blade which has a level | step difference.

It is a disassembled perspective view which shows the principal part structure of a turbine provided with the turbine rotor blade by the 1st Embodiment of this invention. It is a perspective view which shows the ultrasonic flaw detection method of the blade fork of the turbine rotor blade by the 1st Embodiment of this invention. It is explanatory drawing of the relationship between the ultrasonic incident angle and the reflectance in an ultrasonic flaw detection method. It is explanatory drawing of the problem at the time of the ultrasonic flaw detection of the conventional wing fork. It is a block diagram of the outer fork of the turbine rotor blade by the 1st Embodiment of this invention. It is explanatory drawing of the refraction angle in the outer fork of the turbine rotor blade by the 1st Embodiment of this invention. It is a block diagram of the outer fork of the turbine rotor blade by the 2nd Embodiment of this invention. It is explanatory drawing of the refraction angle in the outer fork of the turbine rotor blade by the 2nd Embodiment of this invention. It is a block diagram of the outer fork of the turbine rotor blade by the 3rd Embodiment of this invention. It is explanatory drawing of the refraction angle in the outer fork of the turbine rotor blade by the 3rd Embodiment of this invention. It is a block diagram of the outer fork of the turbine rotor blade by the 4th Embodiment of this invention. It is explanatory drawing of the refraction angle in the outer fork of the turbine rotor blade by the 4th Embodiment of this invention.

  Hereinafter, the configuration of the turbine blade according to the first embodiment of the present invention will be described with reference to FIGS.

  Initially, the principal part structure of the turbine provided with the turbine rotor blade by this embodiment is demonstrated using FIG.

  FIG. 1 is an exploded perspective view showing a main configuration of a turbine including a turbine rotor blade according to a first embodiment of the present invention.

  The turbine includes a disk 1, a turbine blade (blade) 2, and a pin 3.

  The disk 1 is a disk-shaped member attached to the outer peripheral side of the rotating shaft, and has a disk fork 4 and a pin hole 5. FIG. 1 shows only a part of the disk 1 and shows a partial cross-sectional shape of the disk 1.

  The disk 1 includes a plurality of forks 6 provided so as to be engaged with the blade implantation portion 7 of the moving blade 2. The forks 6 of the disc 4 are arranged along the rotor axial direction on the outer edge of the disc 1 at intervals corresponding to the intervals of the forks 10 of the wing implantation portion 7.

  The pin hole 5 is for inserting a pin 3 for fixing the rotor blade 2 to the disk 1. The pin hole 5 is manufactured to have the same diameter as the center of the pin hole 11 of the rotor blade 2. A plurality of pin holes 5 are provided in order to disperse stress and improve durability.

  The moving blade 2 includes a fork-type blade implantation portion (wing fork) 7, a blade attachment portion 8, and a blade portion 9.

  The blade implantation portion 7 is a portion located on the disk 1 side in a posture (blade attachment posture) in which the moving blade 2 is attached to the disk 1, and has a plurality of forks 10 and pin holes 11.

  The forks 10 are members that protrude inward in the rotor radial direction in the blade mounting posture, and a plurality of forks 10 are arranged along the rotor axial direction. The fork 10 is provided so as to engage with the fork 6 of the disk 1 and has a plurality of pin holes 11.

  The pin hole 11 is for inserting a pin 3 for fixing the rotor blade 2 to the disk 1 and is provided so as to penetrate through the plurality of forks 10 of the blade implantation portion 7 from the rotor axial direction.

  The blade attachment portion 8 is a portion having a predetermined thickness in the rotor radial direction, and is attached integrally with the blade implantation portion 7. A blade portion 9 is attached to a blade attachment surface 13 on the outer side in the rotor radial direction of the blade attachment portion 8. The blade attachment portion 8 has overhang portions 12 at both ends in the rotor axial direction. The overhanging portion 12 is a portion provided such that the end surface in the rotor axial direction protrudes compared to both end surfaces in the rotor axial direction of the blade implantation portion 7 in the blade mounting posture.

  In this type of turbine, stress is applied to the pin hole 11 as the turbine rotates, and therefore, inspection of the pin hole 11 is regarded as important in order to confirm the reliability of the moving blade in service.

  Next, the ultrasonic flaw detection method for the blade fork of the turbine rotor blade according to the present embodiment will be described with reference to FIG.

  FIG. 2 is a perspective view showing the ultrasonic flaw detection method for the blade fork of the turbine rotor blade according to the first embodiment of the present invention.

  As shown in FIG. 2, in the ultrasonic flaw detection test, an ultrasonic wave U is transmitted to the inside of the blade fork 7 to be inspected using the ultrasonic sensor US, and the defect is determined depending on whether there is a reflection from the defect D or not. Evaluate presence or absence. At this time, in order to apply the ultrasonic flaw detection test to the inspection of the blade fork, as shown in FIG. 2, the ultrasonic wave is reflected inside the blade fork 7 to be inspected to reach the defect.

  Here, the problem at the time of ultrasonic flaw detection of the blade fork will be described with reference to FIGS.

  FIG. 3 is an explanatory diagram of the relationship between the ultrasonic incident angle and the reflectance in the ultrasonic flaw detection method. FIG. 4 is an explanatory view of a problem at the time of ultrasonic flaw detection of a conventional wing fork.

  As shown in FIG. 3, the reflectance is almost 100% when the ultrasonic incident angle is in the range of 35 ° to 55 °. Therefore, when ultrasonic flaw detection is performed by the method of FIG. 2, it is possible to perform high-sensitivity ultrasonic flaw detection when the range of the ultrasonic refraction angle with high reflection efficiency is about 35 to 55 ° due to the characteristics shown in FIG. Is possible.

  FIG. 4A shows a first problem at the time of ultrasonic flaw detection of a conventional blade fork. When the incident angle is 45 ° within the range of 35 to 55 ° and an ultrasonic wave is incident from the incident position P1 to the inspection position (pin hole position) P2, the ultrasonic wave is reflected halfway and returns to the incident position direction. Thus, there may be a case where ultrasonic waves cannot enter the pin hole where stress is applied.

  On the other hand, as shown in FIG. 4B, when the incident angle is 57 °, ultrasonic waves can be incident on the pin hole. However, since the reflectance is low at an incident angle of 57 °, the detection sensitivity of the ultrasonic flaw detection test is lowered.

  Next, the configuration of the outer fork of the turbine rotor blade according to the present embodiment will be described with reference to FIGS. 5 and 6.

FIG. 5 is a configuration diagram of the outer fork of the turbine rotor blade according to the first embodiment of the present invention. 5 (a) is a front view (viewed from the rotor circumferential direction), FIG. 5 (b) is a side view (viewed from the rotor axial direction), and FIG. 5 (c) is FIG. 5 (b). FIG. FIG. 6 is an explanatory diagram of the dependence of the refraction angle on the outer fork of the turbine rotor blade according to the first embodiment of the present invention.

  The outer fork 10B in this embodiment includes two steps 50 and 51 in the width direction.

Here, the size of the outer fork 10B is set to the width of the overhanging portion 12A (hereinafter referred to as w0),
Fork width (hereinafter referred to as w1) on the first step 50,
Fork width on the second step 51 (hereinafter, w2),
Fork width under the second step (hereinafter referred to as w3),
Fork length (hereinafter L1),
Distance (hereinafter referred to as Ls) between the ultrasonic incident point P1 and the end surface of the overhanging portion in the circumferential direction of the rotor (fork end surface on the other side in the circumferential direction ),
The distance (hereinafter referred to as Ld) between the inspection position P2 and the end surface of the overhanging portion in the rotor circumferential direction (fork end surface on one side in the circumferential direction ),
The height of the overhanging portion 12A (hereinafter, h0),
Fork height on the first step (h1),
The height of the first step (hereinafter referred to as hd1),
Fork height on the second step (h2),
The height of the second step (hereinafter referred to as hd2),
Height from the second step to the inspection site (inspection position P2) (hereinafter, h3)
It is defined as

Here, as shown in FIG. 5C, the distance Ld between the inspection position P2 and the end surface of the overhanging portion in the circumferential direction of the rotor is expressed as “Ld” from the angle θ at which the pin hole 11 has a high stress and the radius r of the pin hole. = R × sin θ ”. Further, the distance Ls between the ultrasonic incident point P1 and the end surface of the overhanging portion in the rotor circumferential direction can be changed within a range of “0 to (L1−Ld)”. Further, the height hs of the ultrasonic incident point P1 can be changed within a range of “0 to h0”.

5A and 5B, P1 is an ultrasonic incident point, P2 is an examination site, and an ultrasonic wave is propagated from the incidence point to the examination site along an arrow. The total propagation distance H in the outer fork height direction of this path, the total propagation distance W in the outer fork width direction, and the total propagation distance L in the outer fork length direction are the sizes defined above,
H = h0 + h1 + hd1 + h2 + hd2 + h3
W = w0 + w1 + (w1 + w2) ÷ 2 + w2 + (w2 + w3) ÷ 2 + w3
L = L1-Ls-Ld
It is described.

The refraction angle of ultrasonic waves uses these sizes,
tan ^-1 ((L ² + H ² ) ^1/2 ÷ W)
It is described. This refraction angle is 35 ° ≦ tan ⁻¹ ((L ² + H ² ) ^1/2 ÷ W) ≦ 55 ° (1)
The ratio between the total propagation distance H in the outer fork height direction, the total propagation distance W in the outer fork width direction, and the total propagation distance L in the outer fork length direction is adjusted.

  Next, a specific ratio range of the total propagation distance H in the outer fork height direction, the total propagation distance W in the outer fork width direction, and the total propagation distance L in the outer fork length direction will be described with reference to FIG. .

  FIG. 6 shows the total propagation distance in the outer fork width direction of the refraction angle when the total propagation distance H in the outer fork height direction is constant (= 1) and the total propagation distance L in the outer fork length direction is constant. Represents dependence on W. The curves in the figure represent the refraction angles when L = 0, L = 0.5, L = 1, L = 2, and L = 3, respectively. In the range of the total propagation distance L = 0 to 3 in the outer fork length direction, the total propagation distance W in the outer fork width direction of the refraction angle is set to 0.70 to 4.58.

Since the result explained in FIG. 6 includes a range of ratios of H, W, and L, which are excellent in strength, H: W: L = 1: 0.5 to 3: 0.5 to 3, as shown in claim 2 The ratio between the total height H, the total width W, and the total length L is H: W: L = 1: 0.78 to 2.58: 0 to 2.58 or less, It is preferable to be in the range.

  As described above, according to the present embodiment, the ultrasonic wave can be incident on the inspection position in the range of the refraction angle of 35 to 55 ° without causing the ultrasonic wave to be incident on the two steps provided on the moving blade. it can. Moreover, the incidence rate of the ultrasonic wave to the examination site can be improved. For this reason, UT becomes easy and the reliability of the turbine rotor blade in service can be improved.

  Next, the configuration of the turbine rotor blade according to the second embodiment of the present invention will be described with reference to FIGS. 7 and 8. In addition, the principal part structure of a turbine provided with the turbine rotor blade by this embodiment is the same as that of what was shown in FIG. Further, the ultrasonic flaw detection method for the blade fork of the turbine rotor blade according to the present embodiment is the same as that shown in FIG.

FIG. 7 is a configuration diagram of an outer fork of a turbine rotor blade according to the second embodiment of the present invention. Fig.7 (a) is a front view (figure seen from the rotor circumferential direction), and FIG.7 (b) is a side view (figure seen from the rotor axial direction). FIG. 8 is an explanatory diagram of the dependence of the refraction angle on the outer fork of the turbine rotor blade according to the second embodiment of the present invention.

In the present embodiment, the inspection position P2 is the opposite surface 21 to that shown in FIG. In this case, the total propagation distance H in the outer fork height direction of the ultrasonic propagation path, the total propagation distance W ′ in the outer fork width direction, and the total propagation distance L in the outer fork length direction are:
H = h0 + h1 + hd1 + h2 + hd2 + h3
W ′ = w0 + w1 + (w1 + w2) ÷ 2 + w2 + (w2 + w3) ÷ 2 + w3 + w3
L = L1-Ls-Ld
It is described.

The refraction angle of ultrasonic waves uses these sizes,
tan ⁻¹ ((L ² + H ² ) ^1/2 ÷ W ′)
It is described. This refraction angle is
35 ° ≦ tan ⁻¹ ((L ² + H ² ) ^1/2 ÷ W ′) ≦ 55 ° (2)
The ratio between the total propagation distance H in the outer fork height direction, the total propagation distance W ′ in the outer fork width direction, and the total propagation distance L in the outer fork length direction is adjusted.

  Next, the specific ratio ranges of the total propagation distance H in the outer fork height direction, the total propagation distance W ′ in the outer fork width direction, and the total propagation distance L in the outer fork length direction will be described with reference to FIG. To do.

  FIG. 8 shows the total propagation distance in the outer fork width direction of the refraction angle when the total propagation distance H in the outer fork height direction is constant (= 1) and the total propagation distance L in the outer fork length direction is constant. Represents dependence on W. The curves in the figure represent the refraction angles when L = 0, L = 0.5, L = 1, L = 2, and L = 3, respectively. In the range of the total propagation distance L = 0 to 3 in the outer fork length direction, the total propagation distance W in the outer fork width direction of the refraction angle is set to 0.70 to 4.58.

Since the result explained in FIG. 8 includes a range of ratios of H, W, and L, which are excellent in strength, H: W: L = 1: 0.5-3: 0.5-3, as shown in claim 4 The ratio between the total height H, the total width W, and the total length L is H: W: L = 1: 0.78 to 2.58: 0 to 2.58 or less, It is preferable to be in the range.

  As described above, according to the present embodiment, the ultrasonic wave can be incident on the inspection position in the range of the refraction angle of 35 to 55 ° without causing the ultrasonic wave to be incident on the two steps provided on the moving blade. it can. In addition, the incidence rate of ultrasonic waves on the examination site can be improved. For this reason, UT becomes easy and the reliability of the turbine rotor blade in service can be improved.

  Next, the configuration of the turbine rotor blade according to the third embodiment of the present invention will be described with reference to FIGS. 9 and 10. In addition, the principal part structure of a turbine provided with the turbine rotor blade by this embodiment is the same as that of what was shown in FIG. Further, the ultrasonic flaw detection method for the blade fork of the turbine rotor blade according to the present embodiment is the same as that shown in FIG.

FIG. 9 is a configuration diagram of an outer fork of a turbine rotor blade according to a third embodiment of the present invention. FIG. 9A is a front view (viewed from the rotor circumferential direction), and FIG. 9B is a side view (viewed from the rotor axial direction). FIG. 10 is an explanatory diagram of the dependence of the refraction angle on the outer fork of the turbine blade according to the third embodiment of the present invention.

  The outer fork 10B in the present embodiment includes one step 50 in the width direction.

In FIG. 9, the size of the outer fork 10B is
The width of the overhanging portion 12A (hereinafter referred to as w0),
Fork width (hereinafter referred to as w1) on the first step 50,
Fork width under the first step 51 (hereinafter, w2),
Fork length (hereinafter L1),
Distance (hereinafter referred to as Ls) between the ultrasonic incident point P1 and the end surface of the overhanging portion in the circumferential direction of the rotor (fork end surface on the other side in the circumferential direction ),
The distance (hereinafter referred to as Ld) between the inspection position P2 and the end surface of the overhanging portion in the rotor circumferential direction (fork end surface on one side in the circumferential direction ),
The height of the overhanging portion 12A (hereinafter, h0),
Fork height on the first step (h1),
The height of the first step (hereinafter referred to as hd1),
Height from the first step to the inspection site (inspection position P2) (hereinafter, h2 ′)
It is defined as

In FIG. 9, P1 is an ultrasonic incident point and P2 is an examination site, and an ultrasonic wave is propagated from the incidence point to the examination site along an arrow. The total propagation distance H2 in the outer fork height direction of this path, the total propagation distance W2 in the outer fork width direction, and the total propagation distance L in the outer fork length direction are the sizes defined above,
H2 = h0 + h1 + hd1 + h2 ′
W2 = w0 + w1 + (w1 + w2) ÷ 2 + w2
L = L1-Ls-Ld
It is described. The refraction angle of ultrasonic waves uses these sizes,
tan ^-1 ((L ² + H2 ² ) ^1/2 ÷ W2)
It is described. This refraction angle is
35 ° ≦ tan ⁻¹ ((L ² + H2 ² ) ^1/2 ÷ W2) ≦ 55 ° (3)
The ratio between the total propagation distance H2 in the outer fork height direction, the total propagation distance W2 in the outer fork width direction, and the total propagation distance L in the outer fork length direction is adjusted.

  Next, a specific ratio range of the total propagation distance H2 in the outer fork height direction, the total propagation distance W2 in the outer fork width direction, and the total propagation distance L in the outer fork length direction will be described with reference to FIG. .

  FIG. 10 shows the total propagation distance in the outer fork width direction of the refraction angle when the total propagation distance H in the outer fork height direction is constant (= 1) and the total propagation distance L in the outer fork length direction is constant. Represents dependence on W. The curves in the figure represent the refraction angles when L = 0, L = 0.5, L = 1, L = 2, and L = 3, respectively. In the range of the total propagation distance L = 0 to 3 in the outer fork length direction, the total propagation distance W in the outer fork width direction of the refraction angle is set to 0.70 to 4.58.

Since the result explained in FIG. 10 includes the range of the ratio of H, W, and L, which is excellent in strength, H: W: L = 1: 0.5 to 3: 0.5 to 3, as shown in claim 6 The ratio between the total height H, the total width W, and the total length L is H: W: L = 1: 0.78 to 2.58: 0 to 2.58 or less, It is preferable to be in the range.

  As described above, according to the present embodiment, the ultrasonic wave can be incident on the inspection position in the range of the refraction angle of 35 to 55 ° without causing the ultrasonic wave to be incident on one step provided on the moving blade. it can. Moreover, the incidence rate of the ultrasonic wave to the examination site can be improved. For this reason, UT becomes easy and the reliability of the turbine rotor blade in service can be improved.

  Next, the configuration of the turbine rotor blade according to the fourth embodiment of the present invention will be described with reference to FIGS. 11 and 12. In addition, the principal part structure of a turbine provided with the turbine rotor blade by this embodiment is the same as that of what was shown in FIG. Further, the ultrasonic flaw detection method for the blade fork of the turbine rotor blade according to the present embodiment is the same as that shown in FIG.

FIG. 11 is a configuration diagram of an outer fork of a turbine rotor blade according to a fourth embodiment of the present invention. 11A is a front view (viewed from the rotor circumferential direction), and FIG. 11B is a side view (viewed from the rotor axial direction). FIG. 12 is an explanatory diagram of the dependence of the refraction angle on the outer fork of the turbine rotor blade according to the fourth embodiment of the present invention.

In the present embodiment, the inspection position P2 is the opposite surface 21 to that shown in FIG. In this case, the total propagation distance H2 in the outer fork height direction of the ultrasonic propagation path, the total propagation distance W2 ′ in the outer fork width direction, and the total propagation distance L in the outer fork length direction are:
H2 = h0 + hd1 + h2 ′
W2 ′ = w0 + w1 + (w1 + w2) ÷ 2 + w2 + w2
L = L1-Ls-Ld
It is described. The refraction angle of ultrasonic waves uses these sizes,
tan ⁻¹ ((L ² + H2 ² ) ^1/2 ÷ W2 ′)
It is described. In order to make the refraction angle 35-55 °,
35 ° ≦ tan ⁻¹ ((L ² + H2 ² ) ^1/2 ÷ W2 ′) ≦ 55 ° (4)
The ratio between H2, W2 ′, and L is adjusted so that

  Next, a specific ratio range of the total propagation distance H2 in the outer fork height direction, the total propagation distance W2 in the outer fork width direction, and the total propagation distance L in the outer fork length direction will be described with reference to FIG. .

  FIG. 12 shows the total propagation distance in the outer fork width direction of the refraction angle when the total propagation distance H in the outer fork height direction is constant (= 1) and the total propagation distance L in the outer fork length direction is constant. Represents dependence on W. The curves in the figure represent the refraction angles when L = 0, L = 0.5, L = 1, L = 2, and L = 3, respectively. In the range of the total propagation distance L = 0 to 3 in the outer fork length direction, the total propagation distance W in the outer fork width direction of the refraction angle is set to 0.70 to 4.58.

Since the result explained in FIG. 12 includes a range of ratios of H, W, and L, which are excellent in strength, H: W: L = 1: 0.5 to 3: 0.5 to 3, as shown in claim 8 The ratio between the total height H, the total width W, and the total length L is H: W: L = 1: 0.78 to 2.58: 0 to 2.58 or less, It is preferable to be in the range.

As described above, according to the present embodiment, the ultrasonic wave can be incident on the inspection position in the range of the refraction angle of 35 to 55 ° without causing the ultrasonic wave to be incident on one step provided on the moving blade. it can. Moreover, the incidence rate of the ultrasonic wave to the examination site can be improved. For this reason, UT becomes easy and the reliability of the turbine rotor blade in service can be improved.

DESCRIPTION OF SYMBOLS 1 ... Disc 2 ... Turbine rotor blade 3 ... Pin 4 ... Disc fork 5 ... Pin hole 6 ... Fork 7 of disc 1 ... Blade implantation part 8 ... Blade attachment part 9 ... Blade part 10 ... Fork 10B ... Outer fork 11 ... Pin Hole 12, 12A ... Overhang 13 ... Blade mounting surface 20 ... Outer end surface 21 ... Inner end surface US ... UT sensors 50, 51 ... Step

Claims (8)

A turbine rotor blade having a fork-type blade implantation portion,
An outer fork located at an end in the rotational axis direction of the plurality of forks and having two steps in a radial section of the turbine to be subjected to an ultrasonic flaw detection test;
A wing attachment portion integrally attached to the wing implantation portion on the outside in the radial direction of the rotational axis of the wing implantation portion;
A projecting portion projecting from the outer end surface of the outer fork in the rotation axis direction toward the rotation axis direction at the end portion in the rotation axis direction of the blade attachment portion;
The width of the overhang is w0,
The fork width on the first step is w1,
The fork width on the second step is w2,
The fork width under the second step is w3,
Fork length is L1,
Of the two circumferential fork end faces, the distance between the fork end face on one side in the circumferential direction closer to the inspection position and the inspection position is Ld,
The distance between the fork end surface on the other circumferential side and the ultrasonic incident point is Ls,
The height of the overhanging part is h0,
The fork height on the first step is h1,
The height of the first step is hd1,
The fork height on the second step is h2,
The height of the second step is hd2,
From the second step to the inspection position height and h3,
The total height H is h0 + h1 + hd1 + h2 + hd2 + h3,
The total width W is w0 + w1 + (w1 + w2) ÷ 2 + w2 + (w2 + w3) ÷ 2 + w3,
When the total length L is L1-Ls-Ld,
35 ° ≦ tan ⁻¹ ((L ² + H ² ) ^1/2 ÷ W) ≦ 55 °
A turbine rotor blade characterized by comprising: The turbine rotor blade according to claim 1,
The ratio between the total height H, the total width W, and the total length L is
H: W: L = 1: 0.78 to 2.58: 0 to more than 2.58 ,
Turbine rotor blade characterized by being in the range of A turbine rotor blade having a fork-type blade implantation portion,
An outer fork located at an end in the rotational axis direction of the plurality of forks and having two steps in a radial section of the turbine to be subjected to an ultrasonic flaw detection test;
A wing attachment portion integrally attached to the wing implantation portion on the outside in the radial direction of the rotational axis of the wing implantation portion;
A projecting portion projecting from the outer end surface of the outer fork in the rotation axis direction toward the rotation axis direction at the end portion in the rotation axis direction of the blade attachment portion;
The width of the overhang is w0,
The fork width on the first step is w1,
The fork width on the second step is w2,
The fork width under the second step is w3,
Fork length is L1,
Of the two circumferential fork end faces, the distance between the fork end face on one side in the circumferential direction closer to the inspection position and the inspection position is Ld,
The distance between the fork end surface on the other circumferential side and the ultrasonic incident point is Ls,
The height of the overhanging part is h0,
The fork height on the first step is h1,
The height of the first step is hd1,
The fork height on the second step is h2,
The height of the second step is hd2,
From the second step to the inspection position height and h3,
The total height H is h0 + h1 + hd1 + h2 + hd2 + h3,
The total width W ′ is w0 + w1 + (w1 + w2) ÷ 2 + w2 + (w2 + w3) ÷ 2 + w3 + w3,
When the total length L is L1-Ls-Ld,
35 ° ≦ tan ⁻¹ ((L ² + H ² ) ^1/2 ÷ W ′) ≦ 55 °
A turbine rotor blade characterized by comprising: The turbine rotor blade according to claim 3, wherein
The ratio between the total height H, the total width W ′, and the total length L is
H: W ′: L = 1: 0.78 to 2.58: 0 to more than 2.58 ,
Turbine rotor blade characterized by being in the range of A turbine rotor blade having a fork-type blade implantation portion,
An outer fork located at an end in the rotational axis direction of the plurality of forks and having one step in a radial section of the turbine to be subjected to an ultrasonic flaw detection test;
A wing attachment portion integrally attached to the wing implantation portion on the outside in the radial direction of the rotational axis of the wing implantation portion;
A projecting portion projecting from the outer end surface of the outer fork in the rotation axis direction toward the rotation axis direction at the end portion in the rotation axis direction of the blade attachment portion;
The width of the overhang is w0,
The fork width on the first step is w1,
The fork width under the first step is w2,
Fork length is L1,
Of the two circumferential fork end faces, the distance between the fork end face on one side in the circumferential direction closer to the inspection position and the inspection position is Ld,
The distance between the fork end surface on the other circumferential side and the ultrasonic incident point is Ls,
The height of the overhanging part is h0,
The fork height on the first step is h1,
The height of the first step is hd1,
From the first step to the inspection position height and h2 ',
The total height H2 is h0 + h1 + hd1 + h2 ′,
The total width W2 is w0 + w1 + (w1 + w2) ÷ 2 + w2.
When the total length L is L1-Ls-Ld,
35 ° ≦ tan ⁻¹ ((L ² + H2 ² ) ^1/2 ÷ W2) ≦ 55 °
A turbine rotor blade characterized by comprising: The turbine rotor blade according to claim 5, wherein
The ratio between the total height H2, the total width W2, and the total length L is
H2: W2: L = 1: 0.78 to 2.58: 0 to more than 2.58 ,
Turbine rotor blade characterized by being in the range of A turbine rotor blade having a fork-type blade implantation portion,
An outer fork located at an end in the rotational axis direction of the plurality of forks and having one step in a radial section of the turbine to be subjected to an ultrasonic flaw detection test;
A wing attachment portion integrally attached to the wing implantation portion on the outside in the radial direction of the rotational axis of the wing implantation portion;
A projecting portion projecting from the outer end surface of the outer fork in the rotation axis direction toward the rotation axis direction at the end portion in the rotation axis direction of the blade attachment portion;
The width of the overhang is w0,
The fork width on the first step is w1,
The fork width under the first step is w2,
Fork length is L1,
Of the two circumferential fork end faces, the distance between the fork end face on one side in the circumferential direction closer to the inspection position and the inspection position is Ld,
The distance between the fork end surface on the other circumferential side and the ultrasonic incident point is Ls,
The height of the overhanging part is h0,
The fork height on the first step is h1,
The height of the first step is hd1,
From the first step to the inspection position height and h2 ',
The total height H2 is h0 + h1 + hd1 + h2 ′,
The total width W2 ′ is w0 + w1 + (w1 + w2) ÷ 2 + w2 + w2,
When the total length L is L1-Ls-Ld,
35 ° ≦ tan ⁻¹ ((L ² + H ² ) ^1/2 ÷ W2 ′) ≦ 55 °
A turbine rotor blade characterized by comprising: The turbine rotor blade according to claim 7, wherein
The ratio between the total height H2, the total width W2 ′, and the total length L is
H2: W2 ′: L = 1: 0.78 to 2.58: 0 to 2.58 or less,
Turbine rotor blade characterized by being in the range of

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