KR101645976B1 - Ultrasonic Inspection Device for Dovetail of Turbine Rotor Wheel and Bucket - Google Patents

Abstract

The present invention relates to an ultrasonic inspection apparatus for inspection of a dovetail portion of a turbine rotor, comprising: a main block (10) having a "C" shape and a front side and a front side opened; A fixing block 20 installed on an upper side of the main block 10; A rotation block 30 mounted on the fixed block 20 and rotatable around a Z axis; A mounting block 40 installed in the rotary block 30 so as to be rotatable around the X axis; An ultrasonic probe 50 installed on the mounting block 40; And a plurality of chain blocks 60 connected to the main block 10 so as to be rotatable by a connecting shaft 14 along the side surface of the main block 10.
According to the above-described structure, the present invention can more accurately and effectively check whether there is a defect in the dovetail portion of the wheel and the bucket of the turbine rotor.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an ultrasonic inspection apparatus for ultrasonic inspection of a dovetail portion of a turbine rotor,

The present invention relates to an ultrasonic inspection apparatus for inspection of a dovetail portion of a turbine rotor, and more particularly, to an ultrasonic inspection apparatus for ultrasonic inspection of a dovetail portion of a turbine rotor, And more particularly, to a multi-joint ultrasonic inspection apparatus for testing a dovetail portion of a turbine rotor, which can easily and effectively check whether a tooth of a turbine rotor and a dovetail portion of a bucket are defective by freely adjusting an installation angle of a probe.

Steam turbines used in nuclear power plants and thermal power plants are devices that rotate by this force by striking high temperature, high pressure steam against a plurality of circumferentially arranged blades on the rotor shaft.

The turbine having such a function is composed of a rotor shaft serving as a rotation center, a wheel installed in a ring shape on the rotor shaft, and a plurality of blades installed along the outer peripheral surface of the wheel. And the blades are installed in multiple stages with different lengths depending on the position on the rotor shaft.

The blade located at the final stage of the rotor shaft is the longest and heaviest in length as shown in FIG. 1, (Not shown in the drawings) are formed by forming a plurality of concave-convex fingers on a root of a blade (this is commonly referred to as a bucket) and forming a corresponding pin hole in the wheel, A dovetail coupling method in which a pin is fastened to a coupling hole, and a curved axial entry type.

Even though the blade and the wheel are firmly coupled by the above-described coupling method, cracks may be generated or broken at the coupling portion where the bucket and the wheel are coupled by the vibration generated during the operation of the turbine and the centrifugal force due to the high- And noise may be generated. In severe cases, the blade may be disengaged from the wheel during operation, causing serious damage to the entire power generation facility. Therefore, it is periodically inspected whether cracks are present at the joints between the buckets of the blades and the wheels, and the integrity thereof is evaluated.

However, since the joint between the bucket and the wheel is not exposed to the outside, it is difficult to perform a visual inspection. The surface of the blade, except for the side surface of the blade having a certain plane shape, is a curved surface whose shape is irregular, Also, since the installation interval between the blades is narrow, it is difficult to access the inspection equipment and it is also difficult to inspect this portion using a large-sized inspection apparatus.

For this reason, when inspecting the joining area between the bucket and the wheel, the wedge unit with a small ultrasonic probe is manually brought into contact with the limited position of the blade surface, and the joining portion (weak portion) Since the blades of the blades constituting the turbine are formed in an almost irregular manner in the vertical direction or in the left and right direction on the almost entire surface and the inside of the blades is formed in a complicated structure of a concavo-convex shape, It is impossible to appropriately inspect the vulnerable portion. Therefore, it is necessary to perform the inspection while locating the installation position where the inspection can be performed by locating the wedge unit to which the ultrasonic probe is attached by the trial and error method Choosing an installation location also takes a lot of time The.

In addition, even if the probe (or wedge unit) is properly installed by the trial and error method described above, the probe used for this purpose is composed of one ultrasonic generating unit. Therefore, In order to change the installation position of the transducer, it is necessary to carry out an inspection several times while slightly changing the installation position of the ultrasonic transducer. In this process, since the installation position of the transducer is changed, (Ultrasonic wave generating unit) is directed toward the weak part to be inspected, it takes a lot of time for the inspection.

In order to solve the above problems, the present applicant has developed a wedge unit for ultrasonic flaw detection having a curved surface corresponding to the curved surface of the blade, and has received a patent registration (registered patent No. 1450516). In this patent document, Since the curved surface of the wedge unit is manufactured in accordance with the curved shape of the blade, it is difficult to manufacture the wedge unit separately according to the type of the blade.

Therefore, an ultrasonic inspection apparatus for a dovetail portion inspection of a turbine rotor which can easily and effectively check whether there is a defect in a dovetail portion of a wheel of a turbine rotor or a dovetail portion of a turbine while moving easily into a blade in accordance with a curved shape of a blade having various shapes Development is required.

KR 10-1450516 B1 KR 10-0567662 B1 KR 10-0901964 B1

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in order to solve the problems of the conventional turbine rotor blade ultrasonic inspection apparatus, and thus it is possible to easily enter a narrow space between the blades of the turbine rotor, The ultrasonic inspection apparatus can be firmly and firmly held on the curved surface of the blade by freely adjusting the angle so that the inspection section can be continuously inspected and the reproducibility of the inspection can be ensured by the polygonal ultrasonic inspection apparatus for the dovetail portion inspection of the turbine rotor The present invention has been made in view of the above problems.

The object of the present invention is to provide an ultrasonic inspection apparatus for inspection of a defect on a curved surface, which comprises a main block having a "C" shape and a front side and a rear side opened; A fixed block installed on an upper side of the main block; A rotary block installed in the fixed block and installed to be rotatable around the Z axis; A mounting block installed in the rotary block so as to be rotatable about the X axis; An ultrasonic probe installed in the mounting block; And a plurality of chain blocks rotatably connected to the connecting shaft along the side surface of the main block.

The present invention is characterized in that a connection block is provided between the main block and the chain block for connecting the main block and the chain block so as to be rotatable about the Y axis.

According to another aspect of the present invention, a connection block is coupled to the main block by a coupling shaft, and a coil spring and an elastic spring are inserted into the coupling shaft, respectively.

Further, the present invention is characterized in that the roller is provided on each of the connecting shafts, thereby preventing surface damage of the blades.

In addition, the present invention is characterized in that a plate spring is provided between the fixed block and the rotary block in the shape of a letter "a ".

The present invention is also characterized in that the ultrasonic probe is held in close contact with the curved surface of the blade by being provided with a pair of pressing members which are installed to be elastically protruded from the rotary block by a spring and press one side of the mounting block.

According to the present invention, a stopper for restricting the angles of the torsion springs and the chain blocks is provided at the upper and lower portions of the connecting shaft connecting the main block, the chain block and the neighboring chain blocks, and the torsion springs are sequentially moved from the main block, A different spring is installed so that the strength of the spring is reduced.

In addition, the present invention is characterized in that an arc-shaped or cylindrical-shaped transfer device for transferring the chain block is connected to the rear of the chain block.

According to the present invention, since the ultrasonic inspection apparatus is connected to the chain block of the multi-joint, the ultrasonic inspection apparatus can be easily moved along the space between the blade and the blade.

In addition, according to the present invention, the installation angle of the block body and the connection block of the main block is adjusted around the Y axis, the installation angle of the rotation block is adjusted around the Z axis, and the installation angle of the installation block is adjusted around the X axis The ultrasonic probe installed in the ultrasonic inspection apparatus can be installed close to the curved surface while adjusting the installation angle of the turbine blade in accordance with the curved surface shape of the turbine blade so as to more accurately and effectively check the dovetail defects of the wheel and the bucket can do.

FIG. 1 is a perspective view showing an example of a multi-joint ultrasonic inspection apparatus for inspection of a dovetail portion of a turbine rotor according to the present invention,
FIG. 2 is an exploded perspective view of a multi-joint ultrasound examination apparatus for testing a dovetail portion of a turbine rotor according to the present invention,
Figure 3 is an assembled front view of Figure 2,
4 is an explanatory view illustrating an example in which the main block and the connecting block according to the present invention are angularly adjusted about a Y axis by a coil spring,
FIG. 5 is an explanatory view showing an example in which the rotary block according to the present invention is angularly adjusted about the Z-
FIG. 6 is an explanatory view showing an example in which the installation block and the ultrasonic probe according to the present invention are angularly adjusted about the X-
7 is a perspective view showing an example of a chain block according to the present invention,
8 is a state view showing an example in which a polygonal ultrasonic inspection apparatus for inspection of a dovetail portion of a turbine rotor according to the present invention is installed along a curved surface of a blade.

Hereinafter, the structure and operation of the present invention will be described in more detail with reference to the accompanying drawings, which show preferred embodiments.

The present invention relates to a turbine rotor having a turbine rotor and a turbine rotor. The turbine rotor is easily positioned between a blade and a blade, The present invention provides an ultrasonic inspection apparatus for inspection of a dovetail portion of a turbine rotor capable of effectively checking whether or not a defect exists in a joint portion. To this end, the ultrasonic inspection apparatus of the present invention comprises: A block 10, a fixed block 20, a rotary block 30, a mounting block 40, an ultrasonic probe 50 and a chain block 60.

2 and 3, the vertical direction of the main block 10 is referred to as a "Y axis", the left and right direction as an "X axis", and the forward and backward directions as a "Z axis".

The main block 10 is for fixing an ultrasonic probe 50 that radiates ultrasonic waves while being connected to a chain block 60 which will be described later. The main block 10 has a shape A block body 11 having a side surface and a " C "-shaped front and rear surfaces, a connection block 11 installed on the open side of the block body 11 and rotatably disposed about the Y- 12).

One axial hole 11A is formed on each of the upper and lower portions of the block body 11 and shaft connecting portions 12A and 12B having through holes are formed at both ends of the connecting block 12, The coupling shaft (13) penetrates through the through hole, and both ends are inserted into the shaft hole (11A) formed on the upper and lower sides of the block body (11).

A coil spring S1 and an elastic spring S2 are provided on the coupling shaft 13 and one end of the coil spring S1 is inserted into a coupling shaft 13 provided in a vertical direction, The other end of the block body 11 is fixed to the upper surface of the connecting block 12 so that the block body 11 or the connecting block 12 is fixed to the elastic force of the coil spring S1 The installation angle of the turbine blades is changed according to the shape of the curved surface of the turbine blades while the installation angle of the turbine blades is changed by rotating the coupling shafts 13 as shown in Fig. 12 are detached from the curved surface, they are returned to their original positions by the elastic force of the coil spring S1.

3, the elastic spring S2 is inserted into the connecting block 12 and the inner surface of the upper horizontal portion of the block body 11 of the " C "shape in a state of being fitted to the coupling shaft 13 provided in the vertical direction, So that the block body 11 and the connection block 12 can move relative to each other in the Y-axis direction and are returned to their original positions by the elastic force of the elastic spring S2 .

3, a plate-like washer 13A is inserted between the coil spring S1 and the resilient spring S2 so as to prevent interference between the coil spring S1 and the resilient spring S2, As shown in Fig.

A connecting shaft 14 is vertically installed on the other shaft connecting portion 12B of the connecting block 12 so as to be connected to a chain block 60 described later. The roller 15 is installed to prevent surface damage of the blade which may be generated when the ultrasonic inspection apparatus enters along the curved surface of the turbine blade. At this time, on the upper and lower ends of the connecting shaft 14, A coupling screw SC is provided to fasten the coupling shaft 14 and the shaft coupling portion 12B of the coupling block 12.

The fixed block 20 is formed on the upper side of the main block 10 and is formed in a shape of a letter "L" as shown in FIGS. 2 and 3, And the upper surface of the vertical portion is formed with a coupling portion 21 having a "C" shape in cross section by opening both side surfaces and the upper surface, and the coupling portion 21 are formed with a pair of coupling holes 21A formed with threads and the rotary block 30 to be described later is coupled to the coupling hole by the coupling member B2 so that the rotary block 30 can rotate about the Z- Respectively.

3, one end of a leaf spring S3 having an inverted "" -shaped shape is inserted and the other end is fixed to the rotating block 30 at an inner side of the lower end of the engaging portion 21 of the fixed block 20 The rotary block 30 is rotated about the Z axis as shown in FIG. 5, so that the installation angle of the rotary block 30 is appropriately adjusted and returned to the original position by the elastic force of the leaf spring S3.

2, the rotary block 30 includes a fixing block 20 and a fastening member B2 at the center thereof. The rotary block 30 is rotatably mounted on the fixed block 20, And a through hole 32 for coupling the mounting block 40 with respect to the X axis about the X axis is formed on the upper surfaces of both ends through a fastening member B3 to be described later .

As shown in FIG. 3, spring mount holes H are formed at both ends of the rotary block 30 so that upper surfaces of the spring mount holes H are opened vertically. Springs S4 are inserted into the spring mount holes H And a pressing member 33 is provided on the upper portion of these springs S4 so as to protrude upward by the elastic force of the spring S4.

When a mounting block 40 to be described later is installed on the rotary block 30 so as to be angularly adjustable about the X axis by the structure of the rotary block 30 as described above, a pair of pressing members 33 are mounted on the mounting block 40 The ultrasonic probe 50 is installed on the mounting block 40 as shown in Fig. 6 and then the ultrasonic inspection apparatus 1 is rotated by the blade and the blade The ultrasonic probe 50 is brought into close contact with the curved surface of the blade while appropriately adjusting the installation angle of the ultrasonic probe 50 corresponding to the curved shape of the blade.

An upper portion of the rotary block 30 is provided with a mounting block 40 connected to the rotary block 30 through a fastening member B3 so as to rotate around the X axis. The mounting block 40 is provided with a dovetail portion An ultrasonic probe 50 is installed to transmit and receive an ultrasonic signal so that an ultrasonic signal generated from a wedge portion (not shown) of the ultrasonic probe 50 is transmitted to a weak portion such as a dovetail portion And then transmitted to the ultrasonic inspection system through the communication cable L or the like.

The main block 10 to which the ultrasonic probe 50 is connected is provided with a plurality of chain blocks 60 along the side thereof so as to position the ultrasonic probe 50 at a desired position on the turbine blade, 7, each of the chain blocks 60 has a curved surface R on one side thereof and a pair of adjacent chain blocks 60 or main blocks The connecting shaft 14 having the roller 15 as described above is coupled to the coupling portions 61 and 62 by the screws SC, A plurality of such chain blocks 60 are connected to each other by a required length and then these chain blocks 60 are connected to a chain block transfer device (not shown) connected to the end of the chain block 60, The blade 2 and the blade < RTI ID = 0.0 > The ultrasonic inspection apparatus 1 connected to the main block 10 connected to the front of the chain block 60 located at the foremost end is positioned on the curved surface of the blade to be inspected The installation angle of the blade 2 is appropriately adjusted corresponding to the curved shape of the blade 2 as shown in Fig.

On the other hand, it is necessary that the state in which the main block 10 and the chain block 60, which are appropriately angle-adjusted corresponding to the curved surface shape, are in close contact with the curved surface of the blade, 1 and 2, the torsion spring SP and the torsion spring SP are formed on the upper and lower portions of the connecting shaft 14 connecting the main block 10, the chain block 60 and the adjacent chain blocks 60, And a stopper ST for adjustment are respectively installed.

At this time, the torsion springs SP are provided with different springs so that the intensity of the torsion is sequentially decreased as the distance from the main block 10 increases, When the leading end portion (the chain block 60 close to the main block 10 or the main block 10) is angularly adjusted in accordance with the curved surface of the blade when entering the blade 1, The chain block 60 does not float in a plane direction opposite to the plane of the blade, but enters the curved surface of the blade as a whole and stably stays.

)범위 내에서만 각도가 조절되도록 제한되고, 그 결과 연결블록(12) 및 체인블록(60)이 과도하게 접히거나 반대 방향으로 완전히 뒤집히지 않으면서 토션스프링(SP)에 과압력이 작용하여 변형되는 것이 방지된다.The stopper ST is formed of a plate having three sides so that one side of the stopper ST is in contact with the shaft connecting portion 12B of the connecting block 12 or the side surface of the engaging portion 61 of the chain block 60 The connecting block 12 and the chain block 60 are positioned such that the connecting block 12 and the chain block 60 are spaced from each other by a predetermined angle with respect to the engaging portion 61 of the chain block 60. As a result, (ST) by a predetermined angle

, And as a result, the connection block 12 and the chain block 60 are excessively folded or overturned completely in the opposite direction, so that the overpressure acts on the torsion springs SP and is deformed Is prevented.

When using the ultrasonic testing apparatus for ultrasonic inspection of the dovetail portion of the turbine rotor of the present invention configured as described above, the transfer devices 100A and 100B, which are arc-shaped or cylindrical, are provided at the rear of the chain block 60 of the ultrasonic inspection apparatus 1 ), And will be described below as one embodiment.

≪ Example 1: Example of using arc-shaped transfer device 100A >

The conveying apparatus 100A according to the first embodiment includes a guide block formed in a arc shape as shown in FIGS. 9 and 10, and a conveying block in which a motor is slidably conveyed along the guide block, And the chain block 60 of the ultrasonic inspection apparatus 10 is connected to one side of the ultrasonic probe 10.

At this time, a gear portion having teeth on one side is provided on the bottom surface of the guide block, and a driving gear for engaging with the gear portion is provided on the rotation shaft of the motor, and the motor is rotated so that the moving block is relatively moved along the guide block .

The conveying block is moved along the guide block as the motor of the conveying block is rotated clockwise or counterclockwise by the conveying device 100A having the above-described structure, and by the operation of the conveying block, 1) is seated in the guide block and stored, and then is drawn outward through the tip of the guide block to enter the space between the blade and the blade.

≪ Embodiment 2: Example using cylindrical transfer device 100B >

11 and 12, the transfer device 100B according to the second embodiment has a cylindrical shape, a housing space formed therein, a housing having a through-hole formed at one side thereof to communicate with the housing space, The ultrasonic inspection apparatus 1 includes a cylindrical fixed body fixedly installed in an inner receiving space of the fixed body, and a ring shaped rotary body installed to surround the outer peripheral surface of the fixed body and rotated by a motor. The chain block 60 is installed on the outer circumferential surface of the rotating body by rotating the rotating body while being fixed to the rotating body.

When the chain block 60 of the ultrasonic inspection apparatus 1 is wound on the rotating body and housed inside the housing by the transfer device 100B having the above structure and the motor is driven to rotate the rotating body, The ultrasonic inspection apparatus 1 enters the space between the blade and the blade.

As described above, according to the present invention, since the ultrasonic inspection apparatus is structured so as to be connected to the chain blocks of the joints, the ultrasonic inspection apparatus can be easily moved along the space between the blades and the blades, Since the connecting block has its mounting angle adjusted about the Y axis, the rotating block has its mounting angle adjusted about the Z axis, and the mounting block has its mounting angle adjusted about the X axis, The installed ultrasonic probe can be installed close to the curved surface with its mounting angle being freely adjusted corresponding to the curved surface shape of the turbine blade, so that the defect of the dovetail portion of the wheel and the bucket can be inspected more accurately and effectively.

1: ultrasonic inspection device 2: blade
10: main block 11: block body
11A: shaft hole 12: connecting block
12A, 12B: shaft connecting portion 13:
13A: washer 14: connecting shaft
15: roller 20: fixed block
21: engaging portion 21A: engaging hole
30: rotation block 31: engaging hole
32: through hole 33: pressing member
40: installation block 50: ultrasonic probe
60: chain block 61, 62:
100A, 100B: conveying device B1, B2, B3: engaging member
H: Spring mounting ball R: Surface
S1: coil spring S2: elastic spring
S3: Plate spring SC: Screw
SP: Torsion spring ST: Stopper

Claims (8)

A main block 10 of a "C "
A fixing block 20 installed on an upper side of the main block 10;
A rotation block 30 mounted on the fixed block 20 and rotatable around a Z axis;
A mounting block 40 installed in the rotary block 30 so as to be rotatable around the X axis;
An ultrasonic probe 50 installed on the mounting block 40;
And a plurality of chain blocks 60 connected to the main block 10 so as to be rotatable by a connecting shaft 14 along a side surface of the main block 10,
The connection shaft 14 connecting the main block 10 to the chain block 60 and the neighboring chain blocks 60 is provided with a torsion spring SP and a stopper Wherein the torsion spring (SP) gradually decreases in intensity as the torsion spring (SP) moves away from the main block (10).
The method according to claim 1,
And a connecting block 12 for connecting the main block 10 and the chain block 60 so as to be rotatable about the Y axis is provided between the main block 10 and the chain block 60. [ A multi-joint ultrasound examining device for dovetail part inspection.
The method of claim 2,
The connection block 12 is coupled to the main block 10 by a coupling shaft 13 and a coil spring S1 and an elastic spring S2 are inserted into the coupling shaft 13 A multi-joint ultrasonic inspection apparatus for the dovetail portion inspection of a turbine rotor.
The method according to claim 1,
Wherein the connection shaft (14) is provided with a roller (15), respectively, to prevent surface damage of the blade.
The method according to claim 1,
Wherein a plate spring (S3) is provided between the fixed block (20) and the rotary block (30) in the shape of a letter "A".
The method according to claim 1,
The rotary block 30 is provided with a pair of pressing members 33 which are installed to be elastically protruded by a spring S4 and press one side of the mounting block 40 so that the ultrasonic probe 50 Wherein the ultrasonic probe is held in close contact with a curved surface of the turbine rotor.
delete The method according to claim 1,
And a transfer device (100A, 100B) of the arc shape or cylindrical shape for transferring the chain block (60) is connected to the rear of the chain block (60). .

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