JP2017217653A - Laser-peening device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize improvement of execution efficiency of laser-peening and a reduction in execution cost by allowing execution to be completed at a time by one processing device with respect to one through-hole of a fork type moving blade implant section.SOLUTION: A laser-peening device according to one embodiment comprises: an irradiation head 10 irradiating an inner peripheral surface of a through-hole 6 with a laser beam; a multiple coupling section 16 which is coupled to the irradiation head 10, can expand a stroke of at least the whole length of the through-hole 6 by a fluid pressure and transmit rotation to the irradiation head 10, and consists of a nested type multiple pipe; light guide tubes 18 and 19 forming a laser beam path guiding the laser beam from a laser oscillator 11 and introducing the laser beam to the irradiation head 10; a head rotation mechanism 14 coaxially housing the multiple coupling section 16, giving the rotation to the multiple coupling section 16 and controlling a laser irradiation position in a circumferential direction with respect to the inner peripheral surface of the through-hole 6; head axial direction control means controlling a position in an axial direction of the irradiation head 10 in the through-hole 6; and liquid feed means supplying liquid to the irradiation head 10.SELECTED DRAWING: Figure 2

Description

  Embodiments described herein relate generally to a laser peening apparatus that irradiates a surface of a structure with laser light and applies compressive residual stress.

  In a steam turbine used in a power plant, a turbine stage is formed by a pair of moving blades and stationary blades, and the turbine stages are arranged in a plurality of stages.

  In recent years, in power plants, in order to improve plant thermal efficiency by improving exhaust loss, the last stage of the low-pressure turbine and the preceding paragraph have been directed to lengthening the moving blades. When the moving blade is made longer, a large centrifugal force acts on the moving blade implantation portion of the disk on the turbine rotor side during plant operation. In the turbine stage with longer blades, a fork-type implant structure is adopted at the joint between the disk and the rotor blade so as to withstand this large centrifugal force.

  In this type of fork-type implant structure, the base blade implant portion of the moving blade is formed in a fork shape, and the same disc implant portion is formed in the disc. The wing implantation part and the disk implantation part are alternately combined, and a coupling pin is inserted into a plurality of pin holes provided so as to penetrate the coupling part.

  In such a fork-type implant structure, high tensile bending stress due to centrifugal force is applied to the inner surface of the pin hole and the coupling pin. A material having a sufficient strength against this tensile bending stress is adopted for the rotor including the disk, the rotor blade, and the connecting pin.

  In the fork-type implant structure, as a measure to prevent damage due to stress corrosion cracking, the surface of the wing and disk implants and the surface of the connecting pin are subjected to processing such as shot peening, and the material surface is subjected to compressive stress. Is conventionally performed.

  By the way, in recent years, in the fork-type implant structure, damage examples due to stress corrosion cracking have been reported on the inner peripheral surface of the pin hole.

It is difficult to perform shot peening on the surface of the pin hole inner peripheral surface. As an alternative method, for example, a method for improving the material display strength by applying a compressive stress to the inner peripheral surface of the pin hole by laser peening using a laser has been proposed.
In addition, a construction system specialized in laser peening processing for pin holes in a fork-type implant structure of a turbine rotor blade is disclosed.

JP 2010-43595 A JP 2011-6789 A

  In recent years, in the final paragraph of the turbine and the previous paragraph, as the moving blades become longer, the fork-type implant structure becomes larger and its width tends to increase.

  On the other hand, an increase in the length of the rotor and an increase in the distance between the bearings of the bearings that support the rotor increase the size of the turbine building. Therefore, it is not preferable to increase the length of the rotor. In particular, the increase in the interval between the disks directly connected to the extension of the rotor must be minimized.

  For this reason, the longer blades of the turbine blades increase the width of the disk of the fork-type implant structure, but the distance between adjacent disks tends to be narrower. From the viewpoint of performing laser peening on the inner peripheral surface of the pin hole penetrating the fork-type implant structure, access to the construction object of the laser machining apparatus is restricted by a narrow disk interval.

  For this reason, in the construction of the inner peripheral surface of the pin hole by the conventional laser peening apparatus, it may not be possible to construct one pin hole at a time from one side of the disk. In such a case, the laser peening apparatus is moved to the other side of the disk and construction from the opposite side is added, or laser peening apparatuses are arranged on both sides of the disk, and simultaneous construction is performed by two processing apparatuses. There was a need.

  In a steam turbine of a power plant, the number of pin holes in a fork-type implant structure is considerable, so one laser peening device can be used for one pin hole to improve construction efficiency and reduce construction costs. It was hoped that construction could be completed at once.

  The present invention has been made in view of the above-described problems of the prior art, and can improve the construction efficiency of laser peening by allowing a single machining apparatus to complete the construction for one through hole at a time. Another object of the present invention is to provide a laser peening apparatus that can realize a reduction in construction cost.

  In order to achieve the above object, a laser peening apparatus according to the present invention provides a laser beam for an inner peripheral surface of a through hole penetrating in the rotor axial direction in a rotor blade implantation structure that couples a disk and a rotor blade of a turbine. A laser peening apparatus for applying compressive residual stress by irradiating a laser beam toward an inner peripheral surface of the through-hole and an irradiation head connected to the irradiation head, and at least the entire length of the through-hole. Stroke can be extended by fluid pressure, and multiple connecting parts consisting of nested multiple tubes that can transmit rotation to the irradiation head, and a laser beam path for guiding the laser beam from the laser oscillator are formed, and the laser beam is introduced into the irradiation head. The light guide tube and the multiple coupling portion are coaxially accommodated, and the rotation of the head for controlling the laser irradiation position in the circumferential direction with respect to the inner circumferential surface of the through hole by rotating the multiple coupling portion And a head axial direction control means for controlling the position of the irradiation head in the axial direction in the through hole, and a liquid feeding means for supplying a liquid to the irradiation head, and extending the multiple connecting portion. However, the irradiation head is moved in the through hole to perform laser peening on the inner peripheral surface of the through hole.

  According to the present invention, it is possible to improve the construction efficiency of laser peening and reduce the construction cost by making it possible to complete the construction for one through hole at a time with one processing device.

It is sectional drawing which shows the fork type implantation structure which couple | bonds the moving blade and disk of the steam turbine which are construction objects. It is sectional drawing which shows the state before the construction start of the laser peening apparatus by 1st Embodiment installed between the adjacent paragraphs. It is sectional drawing which shows the laser peening apparatus by 1st Embodiment in the state which the irradiation head reached to the exit of a through-hole, and the construction was completed. It is sectional drawing which shows the irradiation head inserted in the through-hole. It is a figure which shows the VV cross section in FIG. It is sectional drawing which shows the state before the construction start of the laser peening apparatus by 2nd Embodiment installed between the adjacent paragraphs. It is sectional drawing which shows the laser peening apparatus by 1st Embodiment in the state which the irradiation head reached to the exit of a through-hole, and the construction was completed. In 3rd Embodiment, it is a figure which shows the positional relationship in the alignment guide means and penetration. It is a figure which shows the AA arrow cross section in FIG. In 4th Embodiment, it is sectional drawing of the moving blade implantation part which attached the moving blade simulation body.

  Embodiments of a laser peening apparatus according to the present invention will be described below with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a diagram showing a fork-type implant structure for connecting a moving blade and a disk of a steam turbine to be constructed. In FIG. 1, reference number 1 indicates a rotor of the steam turbine, and reference number 2 indicates a disk holding the moving blade 3.

  On the base side of the moving blade 3, a blade implantation portion is formed in which a plurality of blade forks 4 are arranged in the axial direction of the rotor 1 at regular intervals. Similarly, on the disk 2, a plurality of disk forks 5 are arranged at regular intervals in the axial direction of the rotor 1. The blade forks 4 and the disk forks 5 are combined so as to alternately overlap, and the rotor blades 3 are restrained in the axial direction of the rotor 1.

  Further, a plurality of pin holes (through holes) 6 are formed in the axial direction of the rotor 1 so as to penetrate the overlapping blade fork 4 and disk fork 5. By inserting a coupling pin (not shown) into each pin hole 6, the moving blade 3 is coupled to the disk 2 so as to be restrained in the radial direction of the disk 2 even when subjected to centrifugal force. As shown in FIG. 1, such a fork-type implantation structure is adopted in a structure in which a moving blade 3 is coupled to a disk 2 in a plurality of paragraphs.

  The laser peening apparatus according to the present embodiment applies a stress improving process for forming a compressive residual stress on the inner peripheral surface of the pin hole 6.

  2 and 3 are views showing the laser peening apparatus according to the first embodiment of the present invention. Among these, FIG. 2 has shown the state before the construction start of the laser peening apparatus installed between the adjacent paragraphs. Reference numeral 10 indicates a laser light irradiation head located at the entrance of the pin hole 6. FIG. 3 shows a state where the irradiation head 10 reaches the outlet of the pin hole 6 and the construction is completed. Of the end faces 2a and 2b on both sides of the disk 2, the one with the end face 2a is the construction start side, and the one with the end face 2b is the construction completion side.

  A space 7 is formed between the disk 2 to be constructed and the disk 2A adjacent to the construction start side. Similarly, a space 8 is formed between the disk 2 and the disk 2B adjacent to the construction completion side.

  The laser peening apparatus according to the present embodiment includes a laser light guide 12 that guides laser light oscillated from a laser oscillator 11 to the irradiation head 10, a head rotation driving unit 14 that rotates the irradiation head 10, and the irradiation head 10. And a multiple connecting portion 16 that is connected to the rotation driving portion 14 and can be expanded and contracted in the axial direction.

  In this embodiment, among the spaces 7 and 8 on both sides of the disk 2 to be constructed, the laser light guide unit 12 is disposed in one space 8, and the rotation drive unit 14 and the multiple coupling unit 16 are connected to the other space 7. Is arranged.

  First, the configuration of the laser light guide unit 12 will be described.

  Light guide tubes 18 and 19 are supported on the frame 17 which is a support structure. The light guide tube 18 forms an optical path extending in the radial direction of the disk 2. The light guide tube 19 is liquid-tightly connected to the light guide tube 18, and a first reflection mirror 20 that reflects laser light at a right angle is provided at the connection portion. The light guide tube 19 forms an optical path of laser light parallel to the axial direction of the pin hole 6. The laser beam incident on the first reflection mirror 20 is guided to the irradiation head 10 through the pin hole 6 while changing its direction. The distal end of the light guide tube 19 is coaxially connected to an extension guide 22 that serves as a guide for the irradiation head 10 extending from the pin hole 6.

  The following clamping device 23 is provided so that the laser light guide 12 can be fixed in a state where it is placed in the space 8 between the adjacent disks 2. The clamp device 23 is composed of an air cylinder fixed to the frame 17. When the clamp part 23a is extended, the frame 17 is pressed against the end surface 2b of the disk 2 of the construction target paragraph by the reaction force at this time, so that the entire laser light guide part 12 can be fixed.

  Next, the head rotation driving unit 14 that rotates the irradiation head 10 and the multiple connection unit 16 that connects the irradiation head 10 and the head rotation driving unit 14 and can be expanded and contracted in the axial direction will be described.

  Here, FIG. 4 shows the irradiation head 10 inserted into the pin hole 6. The irradiation head 10 is provided with a second reflection mirror 24 that condenses the laser light incident through the pin hole 6 and reflects it toward the inner peripheral surface of the pin hole 6. An opening 25 through which the laser beam passes is formed on the side surface of the irradiation head 10.

  Such an irradiation head 10 is connected to the rotation drive unit 14 via the multiple connection part 16, and is configured to be movable in the axial direction within the pin hole 6 as the multiple connection part 16 extends.

  As shown in FIG. 2, the head rotation drive unit 14 uses a cylindrical frame 26 as a support structure. In the present embodiment, a direct drive motor 27 which is a kind of flat AC servo motor is used as the motor. The rear end portion of the multiple connecting portion 16 is coupled to the rotor 28 of the direct drive motor 27.

On the other hand, the multiple connecting portion 16 is a double connecting tube in which the inner tube 30a is fitted to the outer tube 30b.
As shown in FIG. 5, the inner tube 30a has a polygonal cross-sectional shape in the case of FIG. The shape of the inner surface of the outer tube 30b is processed so that a gap of 0.01 mm or less is formed between the inner surface of the outer tube 30b and the outer surface of the inner tube 30a following the cross-sectional shape of the inner tube 30a. Thus, the inner tube 30a is allowed to slide in the axial direction, and torque can be transmitted from the outer tube 30b driven by the direct drive motor 27 to the inner tube 30a via the corners of each other. . In order to further enhance torque transmission, the inner tube 30a and the outer tube 30b may be combined using a keyway and a sliding key in combination with a polygonal cross-sectional structure.

  The frame 26 that supports the head rotation driving unit 14 and the multiple coupling unit 16 as described above is provided with the following clamping device 32 so that it can be fixed after being placed in the space 7 between the adjacent disks 2. Yes.

  The clamp device 32 is fixed to the end of the frame 26 opposite to the direct drive motor 27. In this case, the clamp device 32 is composed of an air cylinder, and when the clamp part 34 is pushed out, the tip of the clamp part 34 comes into contact with the end surface 2a of the disk to be constructed. When the clamp portion 34 is further pressed against the end surface 2a, the opposite side of the frame 26 is pressed against the end surface 2d of the adjacent disk 2B by the reaction force. Thereby, the frame 26 can be fixed.

  As shown in FIG. 2, a guide bush 35 is provided at the center of the clamp device 32 so as to be coaxial with the multiple connecting portion 16. The guide bush 35 has the same inner diameter as the pin hole 6 and functions as a guide for guiding the irradiation head 10 to the entrance of the pin hole 6 at the start of construction.

  In order to advance the irradiation head 10 in the pin hole 6, it is necessary to extend the multiple connecting portion 16. In order to position the irradiation head 10 at a predetermined irradiation position, it is necessary to control the position of the pin hole 6 of the irradiation head 10 in the axial direction.

  Therefore, in the laser peening apparatus according to the present embodiment, the following axial position control means for controlling the extension amount of the multiple connecting portion 16 is configured.

  A liquid injection pipe 36 is connected to a rear end portion of the outer pipe 30b constituting the multiple coupling portion 16 via a joint.

  The tip of the inner tube 30a to which the irradiation head 10 is attached is closed, and when a liquid such as water is injected from the liquid injection tube 36 into the inner tube 30a of the multiple connecting portion 16, the inner tube 30a is pressurized with that pressure. Is extended in the pin hole 6 together with the irradiation head 10.

  On the other hand, during laser peening in the pin hole 6, the liquid supplied from the liquid feeding device 38 is irradiated through the pin hole 6 to be processed through the light guide tubes 18 and 19 of the laser light guide 12. Since it is sent to the head 10, the extension of the multiple connecting portion 16 is regulated by the pressure of the liquid. Therefore, by adjusting the balance between the pressure of the liquid in the multiple connecting portion 16 and the pressure of the liquid sent to the irradiation head 10, the speed at which the irradiation head 10 is sent can be adjusted, or the irradiation head 10 can be adjusted. Position control such as positioning at an arbitrary axial position can be performed.

  The laser peening apparatus according to the present embodiment is configured as described above. Next, its operation and effect will be described.

  First, the laser peening apparatus according to the present embodiment is installed as follows in a fork type implantation structure of a turbine stage that is a construction target.

In FIG. 2, the laser light guide 12 is installed in a space 8 on the one end face 2b side of the disk 2 of the turbine stage to be constructed. And the position of the conduit tube 19 is adjusted so that the light guide tube 19 and the pin hole 6 to which laser peening processing will be performed are concentric.
When the alignment is completed, the clamp device 23 is operated to press the clamp portion 23a against the end surface 2c of the adjacent disk 2A. In this way, the frame 17 of the laser light guide 12 can be firmly fixed between the end surfaces 2b, 2c of the disk 2 facing each other.

  On the other hand, the frame 26 that supports the head rotation driving unit 14 and the multiple coupling unit 16 is disposed in the space 7 on the other end surface 2a side of the disk 2 to be constructed. Also in this case, alignment is performed so that the guide bush 35 is concentric with the pin hole 6. Thereafter, when the clamp device 32 is operated and the clamp portion 34 is pressed against the end surface 2a, the head rotation driving portion 14 can be fixed between the end surfaces 2a and 2d of the adjacent disks 2.

  Next, laser peening processing for the inner peripheral surface of the pin hole 6 will be described.

  As shown in FIG. 2, the irradiation head 10 is positioned in the vicinity of the entrance of the pin hole 6 to be constructed before the start of processing. At this time, the irradiation head 10 is supported by the guide bush 35, and the inner tube 30a is accommodated in the outer tube 30b. In this state, the irradiation head 10 is positioned coaxially with the pin hole 6.

  Therefore, the liquid is injected from the liquid injection pipe 36 into the multiple connecting portion 16. At this time, the inner tube 30 a is pushed out while sliding the outer tube 30 b with the pressure of the injected liquid, and the irradiation head 10 is inserted into the pin hole 6. At the same time, the liquid supplied from the liquid feeding device 38 is supplied to the irradiation head 10 through the light guide tubes 18 and 19 and the pin hole 6. Further, laser light is output from the laser oscillator 11.

  In the process of sending the irradiation head 10 through the pin hole 6 along with the extension of the multiple connection portion 16, the direct drive motor 27 is activated, and the rotational torque is transmitted from the multiple connection portion 16 to the irradiation head 10. Thereby, the irradiation head 10 can be rotated.

  When laser light is output from the laser oscillator 11, the laser light is guided to the irradiation head 10 from the first reflection mirror 20 through the pin hole 6 through the light guide tubes 18 and 19 as a path. As shown in FIG. 4, the laser light is collected by the second reflecting mirror 24 in the irradiation head 10, changed in the radial direction of the pin hole 6, passed through the opening 25, and the pin hole 6. Irradiation is directed toward the inner peripheral surface. In the irradiation head 10, the liquid supplied from the liquid feeding device 38 is ejected from the opening 25 toward the inner peripheral surface of the pin hole 6. A compressive stress can be generated on the surface to form a compressive residual stress region.

  In this way, when the irradiation head 10 is sent to the outlet through the pin hole 6 while extending the multiple connecting portion 16, the length of the inner tube 30a is longer than the width of the disk 2 to be constructed. Laser peening can be performed on the entire inner peripheral surface of the pin hole 6.

  As described above, according to the present embodiment, even when the distance between adjacent disks 2 is narrow, the components of the laser peening apparatus are divided and arranged in the spaces 7 and 8 on both sides of the disk 2 to be constructed. Therefore, access to the construction target disk 2 is not restricted by a narrow disk interval.

  Moreover, since it can be applied to one pin hole 6 at a time from one side of the disk 2, the efficiency of laser peening can be greatly increased.

(Second Embodiment)
Next, a laser peening apparatus according to a second embodiment of the present invention will be described with reference to FIGS. The same components as those in the first embodiment shown in FIGS. 2 and 3 are denoted by the same reference numerals, and a duplicate description is omitted.

  In the second embodiment, the amount of extension of the multiple connecting portion 16 is controlled by using a transmission body row that conveys the amount of movement of the linear motion mechanism to the irradiation head 10, and the axial position of the irradiation head 10 is controlled. This is an embodiment.

  FIG. 6 shows a laser peening apparatus installed in the spaces 7 and 8 between adjacent paragraphs before the start of construction. FIG. 7 shows the laser peening apparatus in a state where the irradiation head 10 reaches the exit of the pin hole 6 and the construction is completed.

  In the second embodiment, the laser light guide 12 that guides the laser beam to the irradiation head 10 and the head rotation drive unit 14 that rotates the irradiation head 12 are arranged in the space 7 on the construction start side, and the irradiation head Ten axial position control mechanisms 60 are arranged in the space 8 on the opposite side.

First, the configuration of the laser light guide unit 12 and the head rotation drive unit 14 will be described.
The light guide tube 40 extending in the radial direction of the disk 2 is supported by a frame 41 as a support structure. The light guide tube 40 is connected to the multiplex connecting portion 16 that can be expanded and contracted. Similar to the first embodiment, the multiple connecting pipe 16 includes an inner pipe 30a and an outer pipe 30b. Laser processing from the oscillator 11 is reflected by the first reflecting mirror 20 disposed inside the light guide tube 40 and guided to the irradiation head 10 through the tube of the multiple connecting portion 16.

  The irradiation head 10 is provided with a second reflection mirror 24, and the laser beam condensed by the reflection mirror 24 is irradiated toward the inner peripheral surface of the pin hole 6 through the opening 25 (see FIG. 4). ). This is the same as in the first embodiment.

  In addition, a liquid is introduced into the light guide tube 40 from the liquid feeding device 38, and the liquid is sent to the irradiation head 10 through the multiple connecting portion 16 and ejected from the opening 25. The pressure of the liquid at this time acts in a direction in which the inner tube 30a is slid from the outer tube 30b and the irradiation head 10 is advanced.

  Next, the head rotation drive mechanism 14 will be described.

  In the head rotation drive mechanism 14 according to the second embodiment, the rotation of the servo motor 42 is transmitted to the multiple connecting portion 16 via a gear mechanism. A drive-side bevel gear 43 is attached to the servo motor 42, and a driven-side bevel gear 44 that meshes with the bevel gear 43 is connected to the rear end portion of the outer tube 30 b of the multiple connection portion 16.

  Also in the second embodiment, as shown in FIG. 5, the inner tube 30a has a substantially rectangular cross-sectional shape, and the inner tube 30a is allowed to move in the axial direction and rotates from the outer tube 30b. Is transmitted.

Next, the axial position control mechanism 60 that controls the position in the axial direction of the irradiation head 10 disposed in the space 8 opposite to the head rotation drive mechanism 14 will be described.
The axial position control mechanism 60 according to the second embodiment transmits a linear motion mechanism 62 that linearly moves the push rod 61 and a movement amount of the push rod 61 to a sphere 64a at the tip by a sphere row 64 as a movement transmission medium. To do.

  The sphere array 64 is composed of a plurality of spheres of the same size, and is accommodated in the guide tube 65 so that adjacent spheres contact each other to form one array. The guide tube 65 includes a portion extending in the radial direction of the disk 2 and a portion bent at a right angle ahead of the portion, and is fixed to the frame 67. The tip of the guide 65 is connected to an extension guide 22 that is coaxial with the pin hole 6. A stopper 66 is attached to the extension guide 22 to prevent the spherical row 64 from falling off from the guide tube 65 when the axial position control mechanism 60 is installed.

  Next, the linear motion mechanism 62 that drives the push rod 61 that inputs the movement amount to the spherical body row 64 will be described.

  The linear motion mechanism 62 is a mechanism for moving the push rod 61 in the length direction by a ball screw mechanism having a ball screw shaft 70 and a nut portion 71.

  The ball screw shaft 70 is supported via bearings 72 and 73, and the nut portion 71 is fixed to the push rod support base 74. The ball screw shaft 70 is connected to a servo motor 76 via a coupling 75. The movement of the push rod support 74 is guided by a pair of guide rods 77a and 77b. Stoppers 78 for preventing the push bar support 74 from falling off are attached to both ends of the guide rods 77a and 77b.

  As shown in FIGS. 6 and 7, the irradiation head 10 is at the entrance of the pin hole 6 at the start of the laser peening process. At this time, in the linear motion mechanism 62, the push rod 61 is in the raised position. In the sphere array 64, the spheres are in contact with each other between the irradiation head 10 and the push rod 61 and are continuous without a gap. The leading sphere 64 a of the sphere array 64 is in contact with the irradiation head 10, and the trailing sphere 64 b is in contact with the push rod 61. Accordingly, when the push rod 61 is moved downward as the irradiation head 10 moves forward, the ball row 64 is moved and the movement amount of the push rod 61 can be transmitted to the irradiation head 10. When the push rod 61 is stopped, the irradiation head 10 can be positioned at that position. Thus, as shown in FIG. 7, the irradiation head 10 advances to the exit of the pin hole 6. The moving stroke of the push rod 61 is set longer than the entire length of the pin hole 6. Further, since the movement amount of the push rod 61 can be controlled with high accuracy by the position control of the servo motor 76, the irradiation head 10 can be positioned with high accuracy at any position in the axial direction of the pin hole 6. Is possible.

Next, operations and effects of the laser peening apparatus according to the second embodiment will be described.
First, the laser peening apparatus according to the second embodiment is installed in the fork-type implant structure of the construction target paragraph as shown in FIG.

  The frame 41 that supports the head rotation driving unit 14 and the expansion / contraction connection unit 16 is arranged in the space 7 on the construction start side. At that time, alignment is performed so that the guide bush 35 is concentric with the entrance of the pin hole 6, and then the clamp device 32 is operated, so that the frame 41 of the head rotation drive unit 14 is adjacent to the disk. It can be fixed between two cross sections 2a, 2d.

  On the other hand, the axial position control mechanism is installed in the space 8 on the opposite processing end side. Thereafter, the position of the extension guide 22 at the tip of the guide tube 19 is adjusted so as to be concentric with the outlet portion of the pin hole 6. After the alignment, the axial position control mechanism 60 can be fixed between the end faces 2b and 2c of the disk 2 by operating the clamp device 23.

  At this stage, the pin holes 6 are not filled with the spheres of the sphere array 64. Therefore, the stopper 66 at the tip of the guide tube 65 is removed so that the sphere can be removed from the guide tube 65. Then, if the push rod 61 is moved to the upper limit of the stroke, the spherical body row 61 can be put into the pin hole 6 without a gap as shown in FIG.

  Next, the laser peening process for the inner peripheral surface of the pin hole 6 in the construction target paragraph will be described.

  As shown in FIG. 6, the irradiation head 10 is supported by a guide bush 35, and the inner tube 30a is accommodated in the outer tube 30b. In this state, the irradiation head 10 is positioned coaxially with the pin hole 6.

  Therefore, liquid is introduced into the light guide tube 40 from the liquid feeding device 38. The liquid is injected into the inside of the multiple connecting portion 16. At this time, the inner tube 30 a moves forward while sliding the outer tube 30 b with the pressure of the injected liquid, and the irradiation head 10 is inserted into the pin hole 6.

  In order to restrict the forward movement of the irradiation head 10 as described above, the push rod 61 of the axial position control mechanism 60 is gradually lowered in synchronization with the movement of the irradiation head 10, and the sphere array 64 is pushed by the irradiation head 10. Thus, the inside of the guide tube 65 is moved. When the push rod 61 is stopped, the irradiation head 10 is positioned at a target irradiation position in the axial direction corresponding to the amount of movement of the push rod 61.

  In the head rotation driving mechanism 14, the servo motor 42 is activated, and the irradiation head 10 starts rotating. At this time, laser light is output from the laser oscillator 11, passes through the light guide tube 40, and is reflected by the reflection mirror 20. The reflected laser light passes through the inside of the multiple connecting portion 16 and is collected by the second reflecting mirror 24 and irradiated on the inner peripheral surface of the pin hole 6. During the irradiation of the laser beam, the water flowing through the light guide tube 40 is jetted around the irradiation point to form a water film, so that compression remains on the inner peripheral surface of the pin hole 6 due to the impact of plasma generation. Stress can be applied.

  When the irradiation head 10 rotates, the irradiation head 10 rotates in a state where the spheres of the sphere array 61 are in smooth contact with each other, so that the position of the irradiation head 10 in the axial direction has an influence that causes an error. Never give.

  In this way, in the case of laser peening according to the second embodiment, the amount of movement of the push rod 61 is transmitted to the irradiation head 10 by the sphere array 64, and the axial position of the pin hole 6 of the irradiation head 10 can be accurately positioned. It is possible to accurately apply compressive residual stress to the target site. By repeating this procedure and changing the irradiation position, laser peening can be accurately performed on a necessary portion from the entrance to the exit of the pin hole 6.

(Third embodiment)
Next, a laser peening apparatus according to a third embodiment of the present invention will be described with reference to FIGS.

  The third embodiment is an embodiment in which alignment guide means for facilitating alignment between the irradiation head 10 and the pin hole 6 is added to the laser peening apparatus of the first embodiment or the second embodiment.

  Here, FIG. 8 is a diagram showing a positional relationship between the alignment guide means provided in the clamp device 32 of the head rotation driving unit 14 and the pin hole 6 of the disk 2. FIG. 9 is a view showing a cross section taken along the line AA in FIG.

  In FIG. 8, in the fork type rotor blade implantation portion, the pin holes 6 are arranged concentrically at a predetermined pitch. The pin hole 6 is a construction target hole. The pin holes 6a and 6b that are at equal distances from the pin hole 6 on both sides in the circumferential direction are pin holes used for alignment. The pin hole 6 to be installed is on the axial center of the multiple connecting portion 16 held by the head rotation driving portion 14 by being aligned.

  In order to facilitate such alignment, arm portions 80a and 80b are attached to the clamp device 32 so as to extend on both sides in the circumferential direction, and alignment cylinders 82a and 82b are provided by the arm portions 80a and 80b. Is held. Note that the arm portions 80a and 80b may be configured to have different lengths in accordance with the pin holes 6a and 6b.

  A tapered conical positioning projection 84 is provided at the tip of the piston rod of the alignment cylinders 82a and 82b. When the biston rod advances, the positioning projection 84 is fitted into the pin holes 6a and 6b, respectively. It is supposed to be.

  The alignment cylinders 82a and 82b have arm portions 80a and 80b such that the positioning projections 84 are positioned on the same circumference where the pin holes 6 to be constructed are located, and the pin holes 6 are positioned in the middle of the positioning projections 84. Is held by.

  When the head rotation drive unit 14 is installed, the alignment cylinders 82a and 82b are approximately aligned with the pin holes 6a and 6b. When the piston rods of the alignment cylinders 82a and 82b are pushed out, the positioning projections 84 are fitted into the pin holes 6a and 6b. In this state, the irradiation head 10 accommodated in the head rotation driving unit 14 is The axis is aligned with the pin hole 6.

According to the present embodiment, in addition to facilitating the procedure of aligning the irradiation head 10 with respect to the pin hole 6 at the time of installation, there are the following advantages.
That is, the alignment guide means can be used as a reference for determining in which direction the direction of laser irradiation toward the inner peripheral surface of the pin hole 6 is directed. Specifically, with reference to the arm portions 80a and 80b, it is possible to distinguish whether the direction of laser irradiation is, for example, a direction toward the radial center of the disk or a direction toward the outer side in the radial direction. .

  On the inner peripheral surface of the pin hole 6, there is a portion where stress is concentrated by the centrifugal force received by the moving blade 3 connected via the pin, but not at the entire inner peripheral surface of the pin hole 6 but at the stress concentration portion. It is possible to improve the construction efficiency by performing laser irradiation in a concentrated manner.

(Fourth embodiment)
Next, a laser peening apparatus according to a fourth embodiment of the present invention will be described with reference to FIG.
The first to third embodiments described so far are embodiments in which laser peening is performed on the pin hole 6 in a state where the rotor blade 3 is implanted in the disk 2 in advance.
On the other hand, the fourth embodiment is an embodiment in which laser peening is performed only on the pin hole 6 on the disk 2 side in a state where the rotor blade 3 is removed from the disk 2. This is an embodiment that assumes a case where the inner peripheral surface of the pin hole 6 is reinforced in a turbine that performs repair for newly replacing the rotor blade 3.

  In FIG. 9, reference numeral 90 indicates a moving blade simulation body. This moving blade simulated body 90 has a blade fork 4 having the same structure as the moving blade that is actually attached to the disk 2 and is fitted with the disk fork 5 to form a fork-type implant structure. ing. However, the wing part is not necessary. In a state in which the moving blade simulation body 90 is fitted in the disk 2, a continuous pin hole 6 is formed as in the case where the moving blade 3 is normally implanted in the disk 2. Such a moving blade simulation body 90 is not attached over the entire circumference of the disk 2, but is attached only to the construction site.

  By attaching the moving blade simulation body 90 as a guide for the irradiation head 10 as described above, it is possible to perform laser peening for the inner peripheral surface of the pin hole 6 on the disk 2 side. In that case, when the irradiation head 10 passes through the moving blade simulation body 90, the laser irradiation can be interrupted and the laser irradiation can be performed only on the inner peripheral surface of the pin hole 6 of the disk 2. Thus, the construction time of the pin hole 6 can be shortened by shortening the time for passing the moving blade simulation body 90.

  The laser peening apparatus according to the present invention has been described with reference to preferred embodiments. However, these embodiments are given as examples and are not intended to limit the scope of the invention. Of course, the novel apparatus, method and system described in the specification can be implemented in various forms, and various omissions, substitutions and changes can be made without departing from the spirit of the present invention. is there. The claims and their equivalents are intended to cover the embodiments or improvements thereof within the spirit of the invention.

  DESCRIPTION OF SYMBOLS 1 ... Rotor, 2 ... Disc, 3 ... Moving blade, 4 ... Blade fork, 5 ... Disc fork, 6 ... Pin hole (through-hole), 10 ... Irradiation head, 11 ... Laser oscillator, 12 ... Laser light guide part, 14 DESCRIPTION OF SYMBOLS ... Head rotation drive part, 16 ... Multiple connection part, 17 ... Frame, 18 ... Light guide tube, 19 ... Light guide tube, 20 ... 1st reflective mirror, 22 ... Extension guide, 23 ... Clamp apparatus, 24 ... 2nd reflection Mirror, 25 ... Opening, 26 ... Frame, 30a ... Inner tube, 30b ... Outer tube, 32 ... Clamping device, 34 ... Clamping unit, 35 ... Guide bush, 36 ... Liquid injection tube, 38 ... Liquid feeding device, 40 ... Light guide tube, 41 ... frame, 42 ... servo motor, 43 ... bevel gear, 44 ... bevel gear, 60 ... axial position control mechanism, 61 ... push rod, 62 ... linear motion mechanism, 64 ... spherical row, 65 ... guide Pipe, 70 ... Ball screw shaft, 71 Nut portion, 72, 73 ... bearing, 74 ... push rod support, 76 ... servo motor, 77a, 77b ... guide rod, 75 ... stopper, 82a, 82b ... alignment cylinder, 84 ... positioning projection, 90 ... moving blade Simulated body

Claims (8)

A laser peening apparatus for irradiating a laser beam to an inner peripheral surface of a through hole penetrating in a rotor axial direction in a rotor blade implantation structure for coupling a turbine disk and a rotor blade,
An irradiation head for irradiating a laser beam toward the inner peripheral surface of the through hole;
A multi-connecting portion that is connected to the irradiation head, and that is formed of a nested multi-pipe that is capable of extending a stroke of at least the entire length of the through-hole by fluid pressure and capable of transmitting rotation to the irradiation head;
A light guide tube for introducing a laser beam into the irradiation head by forming a laser beam path for guiding a laser beam from a laser oscillator;
A head rotation mechanism that accommodates the multiple connection portion coaxially, and controls the laser irradiation position in the circumferential direction with respect to the inner peripheral surface of the through-hole by rotating the multiple connection portion;
Head axial direction control means for controlling the axial position of the irradiation head in the through hole;
Liquid feeding means for supplying a liquid to the irradiation head, and
The laser peening apparatus according to claim 1, wherein the irradiation head is moved in the through-hole while the multiple connection portion is extended to perform laser peening on the inner peripheral surface of the through-hole.   The light guide tube is disposed on the opposite side of the disk from the side on which the head rotation mechanism is disposed, the laser light is introduced into the irradiation head through the through hole, and the irradiation head passes through the through hole. The laser peening apparatus according to claim 1, wherein the position of the irradiation head is regulated by the pressure of the supplied liquid. The head axial direction control means is disposed on the opposite side of the disk from the side on which the head rotating mechanism is disposed,
The head axis direction control means has a linearly moving push rod, and a linear motion mechanism that drives the push rod;
A transfer body row that transmits the amount of movement of the push rod to the irradiation head and restricts the movement of the moving head;
A guide tube that houses the movement transmission body row and guides the movement transmission body row to the outlet side of the through hole;
The laser peening apparatus according to claim 1, further comprising:   4. The laser peening apparatus according to claim 3, wherein the movement transmission body row includes a row of a plurality of spheres having the same size.   The laser peening apparatus according to any one of claims 1 to 3, further comprising a clamp device that fixes the head rotation mechanism between adjacent disks.   4. The laser peening apparatus according to claim 1, wherein the head rotation mechanism includes an alignment unit that coaxially aligns the irradiation head with respect to an inlet of the through hole. 5. The alignment means includes a pair of alignment cylinders having positioning protrusions;
A support member that supports the pair of alignment cylinders at positions where the positioning protrusions can be fitted to each of the other through holes located on both sides at the same distance on the same circumference as the through hole to be constructed; The laser peening apparatus according to claim 6, wherein:   4. The laser according to claim 1, further comprising a moving blade simulation body that is attached to a position where the moving blade is removed, and that guides the irradiation head by continuing the through hole. 5. Peening device.

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