JPH0361904B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an ultrasonic flaw detection method for detecting flaws existing inside a material having a circular cross section (including those having a cylindrical shape; the same applies hereinafter), and an implementation of the method. This relates to flaw detection equipment that is used directly.

[Prior art]

Conventionally, an ultrasonic flaw detection method using ultrasonic waves has been adopted as a flaw detection method for materials with a circular cross section. Specific examples of such ultrasonic flaw detection methods include (1) a method in which the probe is fixed and the material is conveyed in the axial direction while rotating, and (2) a method in which the material is rotated and the probe is transported in the axial direction. Two methods have been proposed: (3) a method in which the probe is moved in the axial direction of the material; and (3) a method in which the probe is rotated around the material and the material is conveyed in the axial direction without rotating.

However, the method (1) has the disadvantage that the conveying mechanism is complicated because the material must be fed in the axial direction while being rotated, and there is also a limit to the feeding speed of the material. In addition, if the material is bent, the material will not rotate smoothly, causing so-called "shaking," which also has the disadvantage of making it impossible to increase the rotation speed and reducing productivity. .

In addition, method (2) has the disadvantage that if the material is curved, high-speed rotation becomes difficult and productivity decreases, and method (3) requires a complicated mechanism for rotating the probe. It takes a long time to change the material setup because the probe and the probe fixing part need to be adjusted individually or completely replaced depending on the diameter of the material.
Furthermore, since the gap between the probe and the material is small, if the material is bent, it may come into contact with the rotating body, and the degree of bending must be kept very small. Also, (1) to (3) above
In both of these methods, the flaw detection locus was spiral, resulting in discontinuous flaw detection in the axial direction, which was disadvantageous in terms of the flaw detection length.

[Object of the Invention] The present invention aims to overcome the above-mentioned drawbacks of the prior art, and aims to transport the material in the axial direction without rotating both the probe and the material, and convert the vertical probe into an eccentric probe. By installing a plurality of vertical probes (in which a vertical probe is mounted eccentrically to the left or right with respect to the axis of the material; the same applies hereinafter), it is possible to continuously measure the entire surface of a material with a circular cross section. The aim is to enable high-speed automatic cross-sectional flaw detection.

[Structure of the invention]

A first aspect of the present invention includes a central flaw detection means that transports a material having a circular cross section in the axial direction through a fluid without rotating it, and includes a plurality of vertical probes arranged in the circumferential direction along the outer periphery of the material. , peripheral flaw detection means consisting of a plurality of eccentric probes disposed in parallel with the center flaw detection means and circumferentially along the outer periphery of the material eccentrically with respect to the center of the material; The material is conveyed in the axial direction through a space that can be inspected by the center flaw detection means and the peripheral flaw detection means, thereby continuously detecting the entire cross section inside the material.

Further, the second invention provides an ultrasonic flaw detection system that includes a frame body that accommodates a fluid, a material transport mechanism that transports a material with a circular cross section while being immersed in the fluid, and a probe that is disposed near the material. The apparatus includes: a center flaw detection means consisting of a plurality of vertical probes provided circumferentially along the outer periphery of a material with a circular cross section; and a peripheral flaw detection means consisting of a plurality of eccentric probes arranged in the circumferential direction along the outer periphery of the material, and a pressing means for pressing the material in the axial direction thereof. ing.

〔Effect of the invention〕

The present invention has a structure in which neither the material nor the probe rotates, and it uses a plurality of probes, so there is no need to provide a rotation mechanism like in the past, making the mechanism simple, inexpensive, and furthermore, the entire cross-section can be reliably and continuously detected. Furthermore, compared to conventional systems, especially systems in which the material is transported while rotating, the material can be transported at high speed and productivity can be increased. Furthermore, when the diameter of the material changes, fittings and probes are separately prepared and used depending on the material, so setup time is short and productivity is high from this point of view as well.

In addition, when a copying mechanism is provided, even if a material with a curved portion is conveyed, the entire mechanism swings around the first pin, so the curved portion can be quickly dealt with.
In addition, since the probe itself moves in a direction perpendicular to the axis of the material along with the tracing mechanism, the distance between the probe and the material surface can be kept constant, so even if the material is slightly curved, it can be handled. can do. Further, when the copying mechanism is provided, an optimal value can be obtained as the pressing force or gripping force against the material.

Moreover, by removing the vertical probe of the vertical probe and the eccentric probe and using only the eccentric probe, it is possible to detect flaws in a cylindrical material.

〔Example〕

Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is an overall front view of an ultrasonic flaw detection device embodying the present invention, and FIG. 2 is a right side view of FIG. Water 2 is stored in the tank to a depth of approximately 8 minutes, and water is supplied so that a constant amount is always maintained.

A material W having a circular cross section is inserted through the holes provided in both side walls of the frame body 1 via a sealing member 3,
Rollers 4 and 5 having V-grooves are provided below the material W, and since the rollers 4 and 5 are rotated by a drive source (not shown), the material W is conveyed in the direction of the arrow.

A pedestal 6 is fixed to the upper side wall of the frame 1, which is a fixed member, and two bearings 7 are fixed to each of the pedestals 6 near both ends in the direction perpendicular to the plane of the paper in FIG. 1 (FIG. 2). has been done. A bearing housing 9 is pivotally mounted between the two bearings 7 via a pivot 8, and the housing is rotated toward the center by two compression coil springs 10 provided on the outer periphery of the shaft 8. energized. A base member 11 is fixed on the bearing housing 9. This base member 11 consists of a round bar part 11a and a plate-like part 11b, and a weight 12 for balance adjustment is attached to the round bar part 11a.
It is attached so that it can slide in the axial direction.
The weight 12 is fixed to the round bar portion 11a by bolts 13 at appropriate positions in the axial direction.

A bridge arm 111 is fixed on the pedestal 6, an adjustment bolt 112 is attached to the arm 111, and two compression coil springs 113 are attached to the inside of the arm 111.
As a result, the base member 11 is subjected to an urging force around the shaft 8 in the clockwise direction in FIG.

A female screw member 14 is provided at the tip of the plate-like portion 11b.
is fixed, and a threaded shaft 15 is screwed into the female threaded portion of the female threaded member 14, and when the bundle 16 is rotated, the threaded shaft 15 moves up and down.
A rectangular upper plate 17 is fixed to the lower end of the screw shaft 15, and two metal housings 18 are fixed to the lower surface thereof (see FIG. 2). The pivot 20 is rotatably mounted. Since the bearing 19 is fixed to the substantially rectangular lower plate 21 located below, the bearing 19 and the plate 21 can swing together around the shaft 20.
However, between the plates 17 and 21, four compression coil springs 22 are attached to the adjustment mounting bolts 22.
1, four rollers 32, which will be described later, are pressed against the material W.

A block 23 is fixed to the upper surface of the upper plate 17 for determining the amount of vertical movement of the plate 17 with respect to the base member 11, and a pointer 24 is provided at the end of the block 23, and the upper end is fixed to the base member 11. The pointer 24 along the scale plate 25
is moving up and down.

A holder plate 26 and two gate-shaped brackets 27 are fixed to the lower surface of the lower plate 21 so as to sandwich the plate 26 at a constant distance. A vertical probe 28 and an eccentric probe 29 are attached to both sides of the holder plate 26 via attachment members 30a and 30b, respectively. In this embodiment, four vertical probes 28 and eight eccentric probes 29 are installed, but the number may be increased if the diameter d of the material is large. Note that the holder plate 26 of this embodiment
The four vertical probes 28 constitute the central flaw detection means of the present invention, and the holder plate 26 of this embodiment
and eight eccentric probes 29 constitute the peripheral surface flaw detection means of the present invention.

If the member 30a to which the vertical probe 28 is attached is removed, the circular tube-shaped material can be inspected for flaws using only the eccentric probe 29.

The vertical probe 28 constituting the center flaw detection means
As shown in Fig. 3, four of them are attached to the outer periphery of the material W (not necessarily equally spaced) to detect flaws in the center of the material W, and on the other hand, constitute the peripheral flaw detection means. Eight eccentric probes 29 are attached as shown in FIG. 4, and the axes of the probes 29 are eccentric to the right by a certain amount with respect to the center O of the material. This eccentric direction may be entirely eccentric to the left. Also, the distance between the two gate-shaped brackets 27 in FIG.
One more probe similar to b is attached, and apart from the eight eccentric probes 29 eccentric to the right as in this embodiment,
Eight eccentric probes eccentric to the left (as indicated by two-dot chain lines in FIG. 4) may be additionally installed. When this is done, flaws inside the material can be detected even more accurately.

Furthermore, the mounting member 30b may be omitted so that the eccentric probe 29 is attached to the mounting member 30a having the vertical probe shown in FIG.

Note that the holder plate 26 has three bolts 3.
1 to the lower plate 21.

On the other hand, at each end of the two gate-shaped brackets 27, there are two brackets in total, which are in constant rolling contact with the surface of the material W and can rotate about their respective axes at an angle α to each other. Four rollers 32 are provided. Here, as described above, the weight 12, the base member 11, the screw shaft 1
5. A mechanism composed of the upper and lower plates 17, 21, spring 22, gate-shaped bracket 27, and roller 32 is hereinafter referred to as a "copying mechanism" N.

The reason why the roller 32 is constantly brought into contact with the surface of the material W and the weight 12 is appropriately adjusted to generate an appropriate amount of pressing force against the surface of the material W as described above is because the material W is lifted up. This is to press it against the rollers 4 and 5 to prevent it from happening. Also, material W
If there is a bend in the material W, if that part pushes up the roller 32, for example, the copying mechanism N itself will swing slightly around the axis 8.
Since all the probes 28, 29 move upward at the same time, the gap between the probes 28, 29 and the surface of the material W is always kept constant. Conversely, when the material W becomes convex downward due to bending, the copying mechanism N swings clockwise around the shaft 8 due to its own weight, so the roller 32 is pressed onto the surface of the material W.

In FIG. 1, when the material W is transported in the direction of the arrow at a constant transport speed V (for example, 60 m/sec), the center of the material W is first detected by the vertical probe 28, and then the adjacent eccentric The probe 29 tests the outer periphery except for the center, and eventually the entire cross section of the material W is tested continuously.

When the diameter d of the material W to be detected changes, the handle 16 is turned to move the screw shaft 15 up and down, and the roller 32 is moved up and down to adjust it. Further, by removing the bolts 31, the attached holder plate 26 is replaced with another separately prepared one, and the bolt 31 is again fixed to the lower plate 21. In this manner, in this embodiment, various types of lower plate 21 and probes 28, 29 are prepared depending on the diameter value of the material W, so that they can be quickly replaced. However, since probes are expensive, several sets are prepared so that they can be attached to and detached from the mounting members 30a and 30b.

[Brief explanation of drawings]

FIG. 1 is an overall front view of an ultrasonic flaw detection device embodying the present invention, FIG. 2 is a right side view of FIG. 1, and FIG. 3 is an explanatory diagram showing a flaw detection situation using a vertical probe 28.
FIG. 4 is an explanatory diagram showing a flaw detection situation using the eccentric probe 29. 1...Frame body, 2...Water, 8...Pivot (first pin), 11...Base member, 12...Weight,
N... Copying mechanism, W... Circular cross section material, 17,2
1...Plate, 28...Vertical probe, 29...
Eccentric probe, 32...roller.

Claims (1)

[Claims] 1. Center flaw detection consisting of a plurality of vertical probes arranged in the circumferential direction along the outer periphery of the material, in which a material having a circular cross section is conveyed through a fluid in the axial direction without being rotated. and a peripheral flaw detection comprising a plurality of eccentric probes arranged in parallel with the center flaw detection means and eccentrically arranged with respect to the center of the material in the circumferential direction along the outer periphery of the material. ultrasonic waves for a material with a circular cross section, which continuously detects flaws in the entire internal cross section of the material by transporting the material in the axial direction within a space that can be detected by the center flaw detection means and the peripheral flaw detection means; Flaw detection method. 2. In an ultrasonic flaw detection device having a frame body that accommodates a fluid, a material transport mechanism that transports a material with a circular cross section submerged in the fluid, and a probe disposed near the material, A center flaw detection means consisting of a plurality of vertical probes provided in the circumferential direction along the outer periphery of the material, and a center flaw detection means arranged in parallel with the center flaw detection means and eccentric to the center of the material. A circular cross-section characterized by being provided with peripheral flaw detection means consisting of a plurality of eccentric probes arranged in the circumferential direction along the outer periphery, and pressing means for pressing the material in the axial direction. Ultrasonic flaw detection equipment for materials. 3. The ultrasonic flaw detection device for materials with a circular cross section according to claim 2, wherein the vertical probe can be removed when flaw detecting a circular tube-shaped material. 4. Claims in which the peripheral flaw detection means is comprised of an eccentric probe whose individual axes are eccentric to the right with respect to the axis of the material with a circular cross section, and an eccentric probe whose respective axes are eccentric to the left 2. An ultrasonic flaw detection device for a material with a circular cross section according to item 2. 5 The pressing means is a V provided on the lower side of the material with a circular cross section.
3. The ultrasonic flaw detection apparatus for a material having a circular cross section as claimed in claim 2, which comprises a groove roller mechanism and a copying mechanism provided on the upper side of the material. 6. The copying mechanism includes a balance weight that is swingable around the first pin and is disposed on one side of the pin, and a roller on the lower end that is made of a material with a circular cross section by its own weight and is disposed on the other side. Claim 6 consists of a copying body that is always in contact with the upper side.
An ultrasonic flaw detection device for a material with a circular cross section as described in 2. 7 The copying body includes a base member that is swingably provided on a first pin, a screw shaft that is provided at the end of the member and is movable up and down, and a base member that is swingable around a second pin at the lower end of the screw shaft. a plate, a plurality of gate-shaped brackets fixed to the lower surface of the plate and arranged in the axial direction of the material, a plurality of rollers provided at the lower end of the bracket and in contact with the upper surface of the material, the screw shaft and the plate. 8. The ultrasonic flaw detection apparatus for a material with a circular cross section according to claim 7, comprising a spring means interposed between the cylindrical member and the cylindrical member.