JPS6248190B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field of the Invention The present invention is directed to, for example, repairing cracks and defects in the inner bore surface (inner circumferential wall surface) of a shaft cylinder or tube such as a turbine rotor shaft by using leakage magnetic flux. This invention relates to a leakage magnetic flaw detection device for continuous flaw detection on internal hole surfaces.

Technical background of the invention and its problems Conventionally, this type of leakage magnetic flaw detection device for internal hole surface flaw detection has been used to detect internal holes drilled in a test object W, as shown in FIGS. 1 and 2. By inserting a conductor approximately in the center of surface _W1 and grounding it, and passing a current in the length direction of this conductor, a magnetic field is generated around the conductor, and this magnetic field is It penetrates into the surface layer corresponding to the inner hole surface _W1 of the test object W.

Therefore, as shown in FIG. 2, the magnetic flux caused by the magnetic field appears as a leakage magnetic flux part' across the surface due to the existence of cracks and defective parts _W2 in the inner hole surface _W1 .

Then, magnetic powder made of ferromagnetic material sprayed from a nozzle' provided at the tip of the hose is attached to the leakage magnetic flux part', and this is inspected visually or with an optical fiberscope (endoscope) or a television camera. The inner hole surface _W1 of the object W to be inspected is inspected for flaws by observation.

However, the leakage magnetic flaw detection device for detecting flaws on the inner hole surface described above requires recording on an endoscope, television camera, or videotape in order to confirm and record the flaw detection area on the inner hole surface _W1 .
(1) Since the inner hole surface W ₁ of the object to be inspected W must be subjected to the steps of magnetization, scattering of magnetic powder, and visual inspection in advance, it not only takes a lot of time for the inspection, but also ( 2) For example, it is not only difficult to accurately match the defect position recorded on a videotape with the actual defect position, but also the resolution of the image is unclear, which may lead to detection errors. ,
Since the magnetic powder is mixed with a solvent, there are drawbacks such as contamination of the working environment.

On the other hand, as shown in FIG. 3, another leakage magnetic flaw detection device for internal hole surface flaw detection has a drive unit equipped with an encoder b on a machine frame a located on the outside of the object W to be inspected. A device c is installed, and a drive shaft d that reciprocates in the axial direction while rotating is attached horizontally to one side of the drive device c, and a plurality of ( _three ) rolling motions are attached to one end d1 of the drive shaft d. A holder f equipped with a roller e is provided, and a sensor body g having a sensor g ₁ such as an ultrasonic probe, a probe coil for overcurrent probe, or a sensor for leakage magnetic flux is mounted on this holder f. It is provided so that it can rotate together with f.

Therefore, the above-mentioned leakage magnetic flaw detection device for internal hole surface flaw detection is based on the test object W made of a tube or cylinder, etc.
A sensor body g having a sensor g ₁ in the inner hole surface W ₁ of
Insert. Next, by driving the drive device c located on the outside of the object to be inspected W, this drive device c rotates the drive shaft d and moves the drive device c toward the inner hole surface W ₁ at a constant speed in the axial direction. Inserted with contact.

Then, the holder f, which is integral with the transmission shaft d, rotates while being supported by the rolling roller e.
The sensor of the sensor body g provided on this holder f
At the same time that g ₁ detects cracks and defects on the inner hole surface W ₁ , the encoder b detects and records the position of the defective portion on the inner hole surface W ₁ inspected by the sensor g ₁ . .

However, in the conventional leakage magnetic flaw detection device for internal hole surface flaw detection described above, the sensor _g1 of the sensor body g is driven from the outside of the object W to be inspected, so the transmission shaft d itself is susceptible to bending and There is a risk of twisting, which not only makes it difficult to accurately detect the size and position of cracks and defects on the object W to be inspected, but also there is a risk of leakage. An error occurs between the position and the position, making it difficult to conduct a high-precision inspection. Furthermore, since the sensor _g1 of the sensor body g is disposed between each rolling roller e, when the preceding rolling roller e falls into the defective part of the inner hole surface _W1 , It is also predicted that sensor _g1 itself may be damaged. In addition, since the sensor _g1 is always in contact with the surface to be tested, sensitivity may be impaired or a large number of condensation signals may be generated depending on the surface condition of the surface to be tested and wear of the sensor _g1 . Therefore, it is easy to misidentify it as a defective part, and it is not possible to accurately detect flaws on the inner hole surface _W1 . Furthermore, in the inner hole surface flaw detection means using a pick-up coil or the like, there is a small gap between the inner hole surface _W1 and the sensor _g1 using the pick-up coil or the like, as shown in FIG. , only a part of the leakage magnetic flux ′ can be detected, resulting in a decrease in defect detection sensitivity, and changes in the gap between the sensor g ₁ and the inner hole surface W ₁ result in a decrease in detection sensitivity. There is.

Purpose of the Invention The present invention has been made in view of the above-mentioned circumstances, and is an object of the present invention, in which cracks and defects in the inner hole surface of an object to be inspected are removed using a magnetizing device that moves a holding cylinder equipped with a magnetized conductor and equipped with a motor. A machine frame is fitted in a slidable manner, and each reel of magnetic tape is installed on this moving machine frame, and the inner hole surface is rotated along the entire circumference and moved in the axial direction, thereby creating a magnetic field. The present invention provides a leakage magnetic flaw detection device for detecting flaws on an inner hole surface, the purpose of which is to continuously detect the size and position of a defective portion on the inner hole surface by using leakage magnetic flux with a tape.

Summary of the Invention In other words, the present invention is characterized in that a pair of support mechanisms are provided at both ends of a holding cylinder containing a magnetization conductor and provided with a rack gear in the longitudinal direction, and a motor is attached to a part of the holding cylinder. A plurality of radial arm rods are provided at the front and rear of the mobile frame, each guide roller is provided on each arm rod, and a plurality of arm rods are provided in the front and rear of the mobile frame. A pair of rotating heads, which are integral with the transmission gear, are connected to the cylindrical part formed in the same manner with a pressure roller and a connecting rod, and are rotatably fitted into the cylindrical part.
A magnetic tape is supplied to the movable frame located between the two rotary heads, and a supply reel rotatably fitted and a take-up reel fitted to the movable frame are arranged side by side. a pair of inclined guide pins facing each other is provided on each of the rotating heads adjacent to the pressure roller; a worm gear device having a driven gear meshing with the transmission gear is provided on the moving machine frame; A pinion mounted on the output shaft of this worm gear device is engaged with the above-mentioned rack gear, and by driving the above-mentioned motor, the magnetic tape from the above-mentioned supply reel is applied to the inner hole of the object to be inspected forming a magnetic field. The device is configured so that the size and position of the defective portion on the inner hole surface can be accurately recorded and detected by magnetic recording while being brought into contact with the surface and wound onto a take-up reel.

Embodiment of the Invention The present invention will be described below with reference to an illustrated embodiment.

4 to 10, reference numeral 1 denotes a holding cylinder equipped with a rack gear 1a formed in the longitudinal direction so as to be inserted along the inner hole surface _W1 of the object W to be inspected. A magnetized conductor (conductive wire) 2 is built in the holding cylinder 1 to pass a current through the object W to be inspected to form a magnetic field.
A pair of support mechanisms 3 are provided at both ends of the support mechanism. Note that the tip support portion of the pair of support mechanisms 3 has a plurality of (three) conductive rods 3a connected to the inner hole surface.
The _rear end support part of the support mechanism 3 is adapted to hold an arm rod 3b having a plurality of (three) rolling rollers in contact with the inner hole surface _W1. I'm starting to do that. Further, the conductive rod 3a is connected to the magnetized conductor 2, and the current from the magnetized conductor 2 generates a magnetic field on the circumferential surface of the inner hole surface _W1 of the object W to be inspected through the conductive rod 3a. A defective portion existing on the inner hole surface _W1 of the object to be inspected appears as a leakage magnetic flux portion'. Furthermore, the magnetization conductor 2 is connected via a lead wire 4 to a magnetization generating power source 5 provided with a ground wire 5a (see FIG. 4).

On the other hand, on the outer periphery of the holding cylinder 1, a pair of ridges (keys) 1b are provided in parallel with the rack gear 1a.
is formed as shown in FIGS. 8 and 9, and each guide roller 6a of the moving machine frame 6 is formed in a part of the holding cylinder 1 so as to engage with the bank 1b. The moving machine frame 6 is slidably fitted, and although the moving machine frame 6 slides in the length direction of the holding cylinder 1, it is held in such a manner that it does not rotate.
Further, in the front and rear portions 6b and 6c of the mobile frame 6, a plurality of (three) arm rods 7 arranged in a radial manner are extendable and retractable in the radial direction using an elastic body (not shown) such as a spring. A guide roller 8 made of rubber is pivotally supported on each arm rod 7 so as to be in rolling contact with the inner hole surface _W1 .

On the other hand, a driving motor 9 is provided in parallel to the holding cylinder 1 at a position (middle) close to the rear part 6c of the mobile frame 6, and a driving gear is connected to the output shaft of the motor 9. 9a is pivoted. Further, a pair of rotary heads 10 and 11 are rotatably fitted in a cylindrical portion 6d adjacent to the front portion 6b of the mobile frame 6, connected by a rubber pressure roller 12 and a connecting rod 13. , these two rotating heads 10,1
As shown in FIG. 5 and FIG.
A and 15b are diagonally arranged so as to face each other. Further, a supply reel 17 for supplying the magnetic tape 16 is rotatably fitted into the cylindrical portion 6d of the moving machine frame 6 located between the two rotary heads 10 and 11 via a friction wheel plate (pat) 18. The cylindrical portion 6d located on one side of the supply reel 17 has a take-up reel 19 for winding the magnetic tape 16, which has a frictional surface so that it can slide against the thick roll of the magnetic tape 16. is fitted in.

Therefore, the magnetic tape 16 of the supply reel 17
As shown in FIGS. 6 and 9, the tape is wound around the take-up reel 19 via the inclined guide pins 14a, 14b, the pressure roller 12, and the inclined guide rollers 15a, 15b. The magnetic tape 16 wound around the roller 12 is in contact with the inner circumferential surface _W1 forming the magnetic field.

In particular, the magnetic tape 16 stretched from the supply reel 17 to the take-up reel 19 is connected to the pressure roller 12 and each inclined guide pin 14a, 14.
b, 15a, and 15b, the film can be smoothly wound onto the take-up reel 19 while eliminating positional deviation. That is, the position of the magnetic tape 16 is corrected as shown in FIG.

In other words, correction during movement of the magnetic tape 16 is eliminated by determining the angles of the inclined guide pins 15a, 15b. This inclined guide pin 15a,
The angle of the slanted guide pins 15b is determined based on the horizontal direction of the slanted guide pins 15a, 15b, the inclination angle θ, the projected distance k of both the slanted guide pins 15a, 15b, and the pressure rollers of both the reels 17, 19. If the amount of deviation of the magnetic tape 16 from the magnetic tape 12 is I, then the inclined guide pin 1 is
The inclination angles of 5a and 15b are determined. Furthermore, if the distance k between the two inclined guide pins 15a and 15b is kept constant, even if there is an interval in the horizontal direction, the inclination angle θ will not be affected. Furthermore, if the relationship of formula (1) above is satisfied, even if the magnetic tape 16 shifts slightly during running, a force is applied to the magnetic tape 16 to return it to its original position. Since the magnetic tape 16 automatically returns to its original position, the magnetic tape 16 is attached to each inclined guide pin 14a, 14b, 15a, 15
There is no risk of significant deviation from b.

Therefore, when the rotary heads 10 and 11 rotate, they rotate the supply reel 1 via the friction wheel plate 18 and also cause the pressure roller 12 to revolve around the holding cylinder 1 while rotating. 12 and the inner circumferential surface _W1 , the magnetic tape 16 is unwound from the supply reel 17 and taken up on the take-up reel 19 while being wound thickly and under tension. The leakage magnetic flux generated at the defective portion of the inner circumferential surface W ₁ is magnetically recorded on the magnetic tape 16 when the inner circumferential surface W ₁ on which the pressure roller 12 is located contacts.

On the other hand, in FIG. 5, a bearing 20 is provided at the collar 6e of the movable frame 6 close to the main drive gear 9a.
A transmission gear 21, which is integral with the rotary head 10, is fitted into the bearing 20 so as to mesh with the main drive gear 9a and rotate freely. or,
A worm gear device 23 equipped with a driven gear 22 that meshes with the transmission gear 21 is provided in the movable frame 6 near the transmission gear 21. The pinion 24 is adapted to mesh with the rack gear 1a.

The worm gear device 23 is composed of a worm wheel 23a and a worm gear 23b, and a pinion 24 that meshes with the rack gear 1a is attached to the output shaft of the worm gear 23b. Further, as shown in FIG. 4, the motor 9 is connected to a control panel 26 via a lead wire 25.

Hereinafter, the effects of the configuration of the present invention will be explained.

In the present invention, a tube or cylinder whose circular diameter is measured in advance is inserted into a subject W (see FIG. 4).

Next, as shown in FIG. 5, by driving the motor 9 and energizing the magnetized conductor 2, the conductive rod 3a is passed through the inner hole surface of the object W to be inspected.
Generate a magnetic field around the circumference of W ₁ . Since the main gear 9a rotates when the motor 9 is driven, the rotating heads 10 and 11, which are integral with the transmission gear 21 that meshes with the main drive gear 9a, move around the holding cylinder 1. Along with the slow rotation, the driven gear 22 meshing with the transmission gear 21 also rotates. Therefore, when this driven gear 22 rotates,
Worm wheel 23a of worm gear device 23
Since the worm gear 23b rotates together with the worm gear 23b, the worm gear 23b that meshes with the worm gear 23b rotates the pinion 23 while being decelerated. Since the rack gear 24 meshing with the pinion 23 is held fixed, the pinion 23 rolls on the rack gear 24. In other words, the entire movable frame 6 holding the pinion 23 moves along the bank 1b of the holding cylinder 1. In this case, the two rotary heads 10 and 11 move in a straight line while rotating around the holding cylinder 1, so that they appear to move in a spiral manner. Moreover, the above-mentioned double rotating head 10
A pressure roller 12, which is shaft-mounted across the holding cylinder 1 and 11, contacts the inner hole surface _W1 via a magnetic tape 16 and revolves around the holding cylinder 1 while rotating.

When the rotating heads 10 and 11 are rotated by the transmission gear 21, the supply reel 17 is rotated via the friction wheel plate 18. Then, in advance,
The magnetic tape 16 stretched around the take-up reel 19 via the guide pins 14a, 14b, the pressure roller 12, and the guide pins 15a, 15b is fed out from the supply reel 17, while the magnetic tape 16 is being fed out from the supply reel 17. The film is wound onto the take-up reel 19 while correcting any misalignment via the pressure roller 12 and the guide pins 15a and 15b, and applying appropriate tension. Further, when the magnetic tape 16 contacts the pressure roller 12, the inner peripheral surface
If there is leakage magnetic flux generated in the defective portion of W ₁ , the leakage magnetic flux is continuously magnetically recorded on the magnetic tape 16 .

In this way, the present invention detects the size and position of the defective part _W1 of the object W to be inspected, and
6 for magnetic recording.

Next, the embodiment shown in FIG. 11 is another embodiment of the present invention, and this is a holder 1' in which a holder cylinder 1 and a magnetization conductor 2 are integrated, and the above-mentioned winding A magnetic reproducing head 27 is attached to the running path of the magnetic tape 16 close to the reel 19, and thereby,
The defective part _W1 of the object W to be inspected can be immediately regenerated and detected.

The embodiment shown in FIG. 12 is another embodiment of the present invention, in which guide rollers 28 and 29 are provided on the rotary head, and endless rollers are provided on the guide rollers 28 and 29 and the pressure roller 12. The magnetic tape 16' is stretched,
This embodiment has the same contents as the embodiment shown in FIG. 11 described above.

Furthermore, the embodiment shown in FIG. 13 is another embodiment according to the present invention, in which the holding cylinder 1
A pair of magnetized conductors 30 are provided, and by passing a current between the magnetized conductors 30, a partial magnetic field (partial magnetic field) is generated on the inner circumferential surface _W1 of the object W to be inspected.
The magnetic shield and demagnetized portion are reduced to a minimum.

Effects of the Invention As described above, according to the present invention, the magnetized conductor 2
A pair of support mechanisms 3 are provided at both ends of a holding cylinder 1 having a built-in rack gear 1a in the longitudinal direction, and a moving machine frame 6 equipped with a motor 9 is provided in a part of the holding cylinder 1. This moving machine frame 6 is slidably fitted.
A plurality of arm rods 7 are provided in a radial manner at the front and rear of the frame, each guide roller 8 is provided on each arm rod 7, and a transmission gear 21 is integrated with a cylindrical portion 6d formed in the middle of the moving machine frame 6. A pair of rotating heads 10, 11
are connected by a pressure roller 12 and a connecting rod 13 and fitted in a rotatable manner, and a magnetic tape 16 is supplied to the moving machine frame 6 located between the two rotating heads 10 and 11, and the magnetic tape 16 is fitted in a rotatable manner. The equipped supply reel 17 and take-up reel 19 are arranged side by side, and both the rotary heads 10 and 1 are located close to the pressure roller 12.
1 is provided with a pair of inclined guide pins 14a, 14b, 15a, 15b facing each other, and a worm gear device 23 is provided with a driven gear 22 that meshes with the transmission gear 21 on the moving frame 6. A pinion 24 mounted on the output shaft of the worm gear device 23 is connected to the rack gear 1a.
Since the size and position are magnetically recorded on the magnetic tape 16 that is in close contact with the flaw detection surface using the leakage magnetic flux generated on the inner hole surface _W1 of the test object W, it is possible to accurately locate the defective part. It not only allows flaw detection but also has excellent effects such as easy handling and operation.

[Brief explanation of the drawing]

Fig. 1 is a diagram diagrammatically showing a conventional leakage magnetic flaw detection device for internal hole surface flaw detection, Fig. 2 is an enlarged view showing part A of the chain circle shown in Fig. 1, and Fig. 3 is an already proposed Fig. 4 is a side view of the leakage magnetic flaw detection apparatus for internal hole surface flaw detection according to the present invention, and Fig. 5 is an enlarged view of the main parts of the present invention, and shows a part FIG. 6 is a perspective view showing the relationship between the magnetic tape supply reel and take-up reel incorporated in the present invention, FIG. 7 is a side view of the same, and FIG.
The figure is a sectional view taken along dashed line B-B in FIG. 5, FIG. 9 is a sectional view taken along dashed line C-C in FIG. 5, and FIG. 10 is a sectional view taken along dashed line D-D in FIG. 11 to 13 are diagrams showing other embodiments of the present invention. DESCRIPTION OF SYMBOLS 1... Holding cylinder, 2... Magnetization conductor, 3... Support mechanism, 6... Moving machine frame, 7... Arm rod, 8... Guide roller, 9... Motor, 10, 11... Rotating head , 12... Pressure roller, 13... Connection rod, 16... Magnetic tape, 17... Supply reel,
19... Take-up reel, 23... Worm gear device.

Claims (1)

[Claims] 1 A pair of support mechanisms are provided at both ends of a holding cylinder that has a built-in magnetized conductor and is equipped with a rack gear in the length direction, and a moving machine frame that is equipped with a motor in a part of the holding cylinder can be slid freely. A plurality of radial arm rods are provided at the front and rear of the mobile frame, each guide roller is provided on each arm rod, and the transmission is transmitted to a cylindrical portion formed in the middle of the mobile frame. A pair of rotary heads that are integral with a gear are connected by a pressure roller and a connecting rod and fitted so as to be rotatable, and a magnetic tape is supplied to the movable frame located between the two rotary heads, and the magnetic tape is rotatably fitted. A supply reel and a take-up reel fitted in the reel are arranged side by side, and pairs of inclined guide pins facing each other are provided on the two rotary heads close to the pressure roller, respectively;
The moving machine frame is provided with a worm gear device having a driven gear that meshes with the transmission gear, and a pinion mounted on an output shaft of the worm gear device meshes with the rack gear. Leakage magnetic flaw detection device for hole surface flaw detection.