JP3405604B2 - Polishing equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a metal structure on the inner peripheral surface of a pipe or an inner surface of an inspection hole formed in a shaft core of a large rotating body such as a turbine rotor. The present invention relates to a polishing apparatus used for collecting a replica for inspecting a metal structure of a polishing apparatus. 2. Description of the Related Art Generally, an inspection hole is provided in a shaft portion of a large rotating body such as a rotor of a steam turbine or a water turbine for inspecting a material of a component thereof, an inspection of a welded portion, and the like. .
Using these inspection holes, destructive inspections such as magnetic particle inspection, penetrant inspection, ultrasonic inspection, and eddy current inspection are appropriately combined according to the purpose, and are performed together with visual inspection. In recent years, in order to further improve the safety of equipment, a high level of quality control tends to be required, and the above-mentioned inspection which has been partially performed at regular intervals on a large rotating body or the like in the past. In addition, in order to more accurately and early grasp the tendency of the members to deteriorate over time, it is desired to perform advanced quality control over the entire device. [0004] For example, since a rotor for a steam turbine is operated at a high temperature for a long time, there is a concern that carbides in the constituent members may become coarse or voids may be generated due to creep damage. Therefore, it is required that the metal structure be appropriately observed over the entire length of the rotating body using, for example, a microscope to check the soundness of the member and to detect defects early. By the way, there are various well-known methods for observing a metal structure finely, and among them, a replica method is generally adopted. The replica method involves spraying a solution-like film material on the surface of the metal structure of the part to be inspected, transferring the metal structure to the formed replica film, and subjecting the obtained replica to an electron microscope to observe the metal structure. is there. In order to collect a replica from an object to be inspected by the above-mentioned replica method, it is essential to have a uniform polished surface having a surface roughness of 3.5 to 5.0 μm or less. By observing the replica obtained from the polished surface with an electron microscope, changes in the metal structure can be easily grasped,
It is possible to determine with high reliability the deterioration state of the constituent members of the inspection object and the presence / absence of defects. [0007] However, the polishing operation for observing the metallographic structure is conventionally all performed manually by an inspector, and the polishing portion is limited or the workability is limited. However, there are difficulties in working time and polishing accuracy, and as a result, the locations where replicas are collected are limited. That is, the polishing range is limited to a range that can be reached by an operator from the opening of the inspection hole or the opening of the pipe formed in the component member, for example, a narrow range of at most about 500 mm from the opening, so that a large-sized configuration is required. A replica cannot be collected over the entire member, and it is difficult to grasp the aging state of the entire member. In addition, since the work is manually performed by a worker, the workability is low, and the polishing accuracy varies, which may affect the reproducibility and reliability of the inspection result. An apparatus for collecting a replica in order to improve the workability and the accuracy is disclosed in, for example, Japanese Patent Application Laid-Open No. 57-1540.
No. 38 discloses this. However, the conventional apparatus is not always easy to operate due to the complicated structure of each device, and tends to be complicated in maintenance and management. Therefore, more preferable apparatuses are required. SUMMARY OF THE INVENTION It is an object of the present invention to provide a polishing apparatus capable of easily collecting a replica of a metal structure from a deep part of an object to be inspected and capable of efficiently working even in a narrow working space. . In order to achieve the above object, the present invention is directed to a main body part which extends from an end held outside the object to be inspected to a deep part of an inspection hole of the object to be inspected. A positioning rod formed by extending the rod, and provided at the tip of the main body of the positioning rod so as to be movable in the inspection hole in the inspection hole together with the positioning rod, and to polish the abrasive material in the inspection hole. a polishing head having a drive apparatus for polishing against the parts, provided on the front surface and rear surface of the polishing head, a polishing apparatus having a pair of head pressing device for fixing the polishing head to the inspection hole inner surface At
The polishing head is configured to perform the polishing along a circumferential direction of a portion to be polished.
An eccentric shaft that swings the material and the eccentric shaft
It is characterized in Rukoto and a driving device for rolling. In the polishing apparatus having the above-described structure, the polishing head inserted into the inspection hole is first moved to the polishing portion, which is the inspection target position. The position of the polishing head in the axial direction and the circumferential direction with respect to the inspection hole is adjusted by a positioning rod using a driving device. After the polishing head is positioned at a position facing the portion to be polished, the polishing head is pressed against the inner surface of the inspection hole and fixed. Then, the abrasive is rotated by a driving device,
The part to be polished is polished. Preferably, at this time, the abrasive is oscillated with a constant amplitude in the axial direction and the circumferential direction. An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 2 is an overall configuration diagram showing one embodiment of the polishing apparatus according to the present invention. The polishing apparatus according to the present embodiment has a polishing head 3 provided movably in an axial direction and a circumferential direction in an inspection hole 2 or a pipe along an axis of a test object 1 such as a large rotating body such as a steam turbine. . The polishing heads 3 are held by positioning rods 4 provided concentrically. Further, a driving device 5 for positioning the polishing head 3 at a predetermined position is provided. The driving device 5 is controlled by a control device 6. The driving device 5 can move forward and backward along the rail 7 installed in the axial direction of the inspection hole 2 together with the polishing head 3 and the positioning rod 4, whereby the inspection hole 2 of the polishing head 3 can be moved. Axial positioning is performed on a portion to be polished, which will be described later. Polishing head 3
The rotation of the positioning rod 4 connected thereto is used to perform circumferential positioning with respect to the portion to be polished. FIG. 1 shows the details of the polishing head 3.
An eccentric shaft 9 is provided along an axis in a hollow cylindrical casing 8. The eccentric shaft 9 is held by a central support plate 10 and the tip thereof is
1 is engaged with the long hole 12 drilled. The eccentric plate 11 is supported by an auxiliary shaft 14 extending between the central support plate 10 and a front support plate 13 mounted on the front end face of the casing 8. A drive motor 1 is provided below the eccentric plate 11.
5 is provided, and an abrasive 16a is mounted on a spindle 16 directly connected to the drive motor 15. FIG. 3 shows the positional relationship between the eccentric shaft 9, the eccentric plate 11, and the drive motor 15. When the eccentric plate 11 rotates about the auxiliary shaft 14, the abrasive 16a swings accordingly. The drive motor 15 is connected to an air cylinder 17 as shown in FIG. The air cylinder 17 is supported by a cylinder support plate 18 that rotates about the auxiliary shaft 14. Further, the rear shroud 19 and the inner shroud 2 covering the rear end face of the casing 8
A drive motor 21 for driving the eccentric shaft 9 is provided in a room surrounded by 0 (see FIG. 1). On the other hand, as shown in FIG. 5, the polishing head 3 has holders 22a, 22b, 22 arranged at equal intervals in the circumferential direction.
c and three rollers 23 supported by the rollers.
A retainer 22a supporting the upwardly directed roller 23 is connected to an air cylinder 25 fixed to the front support plate 13 via an expansion 24, while a retainer 22b supporting each downwardly directed roller 23, 22c is directly fixed to the casing 8. FIG. 5 is a view as seen from the front end face of the polishing head 3. The same three rollers 23 are also provided on the rear end face of the polishing head 3 by using similar supporting means (see FIG. 1).
In the drawing, reference numeral 26 denotes an air tube, which guides compressed air to each of the air cylinders 17 and 25. Reference numeral 27 denotes an electric cable, which is connected to each drive motor 1 from an external power supply.
Supply electricity to 5, 21. In order to polish the portion G to be polished (see FIG. 1) using the above-mentioned polishing apparatus, first, the polishing head 3 is connected to the inspection hole 2.
The polishing head 3 is positioned at a predetermined position by operating the driving device 5. Next, compressed air is sent to each of the air cylinders 25 through the air tube 26 and is extended in the radial direction so that each of the rollers 23 on the front end face and the rear end face is inserted into the inspection hole 2.
Pressing against the inner surface fixes the polishing head 3 at that position. Next, compressed air is sent to the air cylinder 17 through the air tube 26, and the drive motor 15 is started while extending in the radial direction and pressing the abrasive 16a against the portion G to be polished. Thus, the polished portion G can be polished by the polishing material 16a. The polishing process starts from the roughing process and proceeds to the finishing process while sequentially replacing the abrasive 16a. To widen the polishing area in the circumferential direction, the drive motor 21 is started to rotate the eccentric shaft 9. At this time, the eccentric plate 11 rotates and the abrasive 16a swings in the circumferential direction, so that the polishing area can be expanded. In order to expand the polishing area in the axial direction of the inspection hole 2, the driving device 5 is operated and adjusted. Expansion 2
Numeral 4 is incorporated to change the position of the roller 23 facing upward, and the length can be adjusted in accordance with the inner diameter of the inspection hole 2 each time the inspection object 1 changes. As described above, according to the polishing apparatus of this embodiment,
While moving the polishing head 3 in the inspection hole 2 in the axial direction, the polishing can be performed from near the end to the deep portion. For this reason, it is possible to collect a replica of the metal structure of the object to be inspected even in the inside of a long plant pipe and deep in the inspection hole of the large rotating body. Further, since most of the work is performed by remote control, it is possible to work efficiently even in a small work space. In particular, work safety can be enhanced in a dangerous work environment such as a radiation control area. In addition, since all polishing processing is performed automatically,
Variations in polishing accuracy are reduced, and reproducibility and reliability of inspection results can be improved. As described above, according to the present invention, a polishing head is provided at the distal end of a positioning rod having a length reaching the depth of the center hole of the test object, and the polishing head is moved to the center by using a head pressing device. It is fixed to the inner surface of the hole and the abrasive is pressed against the polished part of the center hole and polished, so that a replica of the metallographic structure can be easily collected from the deep part of the inspected object, and over the entire area of the inspected object It is possible to determine the state of material deterioration and the presence or absence of a defect. Further, work is performed by remote control, and work can be performed efficiently even in a small work space.
The improvement in workability can greatly reduce the time required for inspection.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a polishing head of a polishing apparatus according to the present invention. FIG. 2 is an overall configuration diagram of a polishing apparatus according to the present invention. FIG. 3 is a sectional view of the polishing head shown in FIG. 1; FIG. 4 is a cross-sectional view of the polishing head shown in FIG. FIG. 5 is a sectional view of the polishing head shown in FIG. 1; [Description of Signs] 2 ... Inspection hole 3 ... Polishing head 4 ... Positioning rod 8 ... Casing 11 ... Eccentric plates 15 and 21 ... Drive motor 16a ... Abrasives 17 and 25 ... Air cylinder 23 Roller

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-302875 (JP, A) JP-A-1-263532 (JP, A) JP-A-2-105036 (JP, A) JP-A-6-302 180275 (JP, A) JP-A-57-154038 (JP, A) Japanese Utility Model Laid-Open No. 5-56350 (JP, U) Japanese Utility Model Application Laid-Open No. 1-9050 (JP, U) (58) Fields investigated (Int. ⁷ , DB name) G01N 1/00-1/36 JICST file (JOIS)

Claims (1)

(1) A positioning rod formed by extending a main body from an end held outside the test object to a deep portion of an inspection hole of the test object. And a driving device that is provided at the distal end of the main body of the positioning rod and is provided so as to be movable in the axial direction in the inspection hole together with the positioning rod, and presses and polishes an abrasive against a polished portion of the inspection hole. a polishing head having, provided on the front surface and rear surface of the polishing head, a polishing apparatus odor and a pair of head pressing device for fixing the polishing head to the inspection hole inner surface
The polishing head is configured to polish the polishing head along a circumferential direction of a portion to be polished.
An eccentric shaft that swings the material and the eccentric shaft
A polishing device, comprising: a driving device for rotating the polishing device.