JPH10123111A - Sensor following device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make constant the relative position between a material to be inspected and a sensor without generating any deflection deformation in the material to be inspected by suspending a following frame with a roller for clamping and a roller for placement at opposing positions at a link mechanism that can be elevated freely with a weight-reducing means and a height position adjustment means. SOLUTION: A link mechanism 1 consists of a link piece 1c where one edge part is supported so that it can be rotated freely for a fixed trestle 1a and the other edge can be rotated for a suspension trestle 1b and the center is scooped out. The link mechanism 1 has a bolt nut 2 as a position adjustment means and a pull spring 3 as a weight-reducing means. A nut 2c is rotated in forward and backward directions and the height position of the suspension trestle 1b, namely a following frame 4, is adjusted according to the outer diameter of a material P to be inspected. In the pull spring 3, its one edge is fitted to a spring mounting plate 1a' at the edge of a horizontal projection piece part 1a', and the other edge is fitted to the link piece 1c, and pulls up the following frame 4, where various kinds of members placed on the suspension trestle 1b are placed, so that the total weight does not operate on the material P to be inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor tracking device in a nondestructive inspection facility, and more particularly to a sensor tracking device which is effective when a material to be inspected is a small-diameter small-diameter steel bar or a small-diameter thin-walled steel pipe.

[0002]

2. Description of the Related Art In order to perform nondestructive inspection of an inspected material such as a steel pipe or a steel bar, which is a long object having a circular cross section, by ultrasonic flaw detection or the like, the inspected material is usually spirally conveyed in its axial direction. In this case, since the axis of the material to be inspected oscillates due to its own bending or eccentric diameter, it is necessary to make the sensor follow this oscillating motion.

For this reason, conventionally, an appropriately shaped guide member, such as a V-shaped member, which is brought into direct contact with a material to be inspected, and an inspection sensor (hereinafter, simply referred to as a sensor) are opposed to each other at a predetermined interval. On the other hand, there has been used a sensor tracking device in which a tracking frame supported by a vertically movable link mechanism is mounted on the upper surface of a material to be inspected and a sensor follows the whirling of the material to be inspected.

However, in the above-described sensor follower, its own weight acts directly on the material to be inspected. For this reason, when the material to be inspected is a small-diameter steel bar or a small-diameter thin-walled steel pipe having a small rigidity, the material to be inspected is bent and deformed, and the relative positional relationship between the sensor and the material to be inspected is changed, thereby lowering the inspection accuracy. In particular, at both ends, since the material to be inspected is in a cantilever state, the above-described amount of bending deformation increases, and the change in the relative positional relationship between the sensor and the material to be inspected greatly increases, thereby significantly deteriorating the inspection accuracy. However, there is a problem that normal flaw detection becomes impossible.

However, bending deformation of the material to be inspected can be prevented by reducing the weight of the following frame itself. However, in this case, the tracking frame is too light to follow the whirling of the material to be inspected, so that the relative positional relationship between the sensor and the material to be inspected changes as described above, thereby lowering the inspection accuracy.

As a sensor follow-up device which does not apply its own weight to the material to be inspected, there is provided an opening through which the material to be inspected passes, and which is opened and closed in a centripetal manner toward the center of the opening. There is a type in which a set of clamping rollers and a follow-up frame in which four ultrasonic sensors are individually variably arranged are suspended on a transport line using balance weights (Japanese Utility Model Laid-Open No. 63-19207).

[0007]

SUMMARY OF THE INVENTION
In the device proposed in Japanese Patent Application Laid-Open No. 3-19207, as shown in FIG. 2 of the Japanese Patent Application Publication, the clamping roller is merely provided on the exit side in the transport direction with respect to the sensor. The roller is configured to rotate in the transport direction of the test object. Therefore, in such a device,
The positional relationship between the material to be inspected and the sensor in the material to be inspected that passes before the tip of the material to be inspected is gripped by the clamping roller will be different from that of the other parts, and the inspection accuracy of the part will be different. It has the drawback that it is inevitable that the unexamined portion is deteriorated.

Further, in the above apparatus, since the rotating direction of the clamping roller is the same as the transport direction of the inspection material and the contact between the inspection material and the roller in the transport direction is point contact, a large bend is formed at the end. In the case of a test piece having a defect, the positional relationship between the test piece and the sensor is not maintained constant at the end of the test piece, so that there is a disadvantage that the test accuracy of the part is reduced and an untested portion is generated. doing.

For this reason, even if the material to be inspected is a small-diameter thin-walled steel pipe which is apt to be flexibly deformed, the flexural deformation of the material to be inspected, particularly the flexural deformation at both ends, can be almost certainly suppressed. It has been desired to develop a sensor tracking device that can minimize the change in the relative positional relationship with the sensor and does not deteriorate the inspection accuracy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and has as its object to prevent the material to be inspected from bending and deforming, and to determine the relative positional relationship between the material to be inspected and the sensor. It is an object of the present invention to provide a sensor follower that can be maintained substantially constant over the entire length.

[0011]

The gist of the present invention resides in the following sensor tracking device.

A sensor follow-up device in a facility for nondestructively inspecting a material to be inspected having a circular cross section conveyed spirally in an axial direction, wherein the device is arranged at a predetermined interval in a direction orthogonal to an axis of the material to be inspected. A pair of placement rollers that are placed opposite to each other, are placed on the upper surface of the material to be inspected, and rotate in contact with and follow the material to be inspected in the opposite direction; It comprises a pair of clamping rollers for separately moving to and away from the lower surface of the inspection material to elastically press and hold the inspection material, and a sensor disposed at a position facing the pair of mounting rollers. A sensor follow-up device, wherein the follow-up frame is suspended from a vertically movable link mechanism having a weight reducing unit and a height position adjusting unit.

In the sensor follower of the present invention, it is preferable that the follower frame is mounted on the link mechanism that can move up and down so as to follow the transport speed of the material to be inspected.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A sensor follower according to the present invention comprises a pair of right and left cylindrical mounting rollers which are placed on the upper surface of a material to be inspected spirally conveyed and rotate to contact and rotate, and the lower surface of the material to be inspected. In addition to gripping the material to be inspected with a total of four rollers (a total of three rollers when passing through the pipe end), a pair of cylindrical front and rear clamp rollers that rotate in contact with and rotate in contact with the elastic force A follow-up frame on which the four rollers and the sensor are mounted is suspended from a vertically movable link mechanism provided with a weight reducing means.

Therefore, while the relative positional relationship between the follow-up frame and the material to be inspected is always kept the same, the total weight of the follow-up frame and the rollers and sensors attached thereto does not affect the material to be inspected. As a result, bending deformation of the material to be inspected is suppressed as much as possible, and the relative positional relationship between the material to be inspected and the sensor is maintained substantially constant during the inspection period, so that highly accurate inspection can be performed.

In the case where the above-mentioned follow-up frame is mounted on a link mechanism which can be moved up and down so as to be movable in the direction of transporting the material to be inspected, the follow-up frame is synchronized with the transport speed when inspecting both ends of the material to be inspected. By moving the frame, the entire circumference can be inspected with high accuracy over the entire length.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a sensor tracking device according to the present invention will
An embodiment will be described in detail with reference to the accompanying drawings.

FIG. 1 is a side view showing an example of a sensor follower according to the present invention, and FIG. 2 is a front view taken along line AA of FIG.

In the drawing, reference numeral 1 denotes a parallelogram-shaped vertically movable link mechanism, one end of which is rotatably supported on the fixed base 1a, and the other end of which is connected to the suspension base 1b. A pair of upper and lower and left and right pairs which are rotatably supported at the same length are formed of link pieces 1c, 1c, 1c, 1c penetrating through the center to reduce the weight.

The link mechanism 1 is provided with a bolt / nut 2 as height position adjusting means and a tension spring 3 as weight reducing means.

The bolt and nut 2 are connected to the upper link piece 1
c, a horizontal projecting piece 1a 'of the fixed base 1a is attached to a connecting plate 1d fixedly interposed between 1c and having a long hole 1e formed in the center.
2b of headed bolt 2a penetrating through the hole drilled in
Has been shut down. By rotating the nut 2c in the normal and reverse directions, the height of the hanging frame 1b, in other words, the following frame 4 attached to the hanging frame 1b can be adjusted according to the outer diameter of the material P to be inspected. Has become.

The bolt / nut 2 constituting the above-mentioned height position adjusting means has a bolt member having a rotating handle attached to the upper end thereof penetrating the horizontal projecting piece 1a 'so as to be axially immovable. Alternatively, a nut member screwed with the threaded portion may be slidably attached to the link pieces 1C, 1C in the longitudinal direction.

One end of the tension spring 3 has a fixed base 1a.
Spring mounting plate 1 erected at the end of the horizontal projecting piece 1a '
a ", the other end of which is attached to the lower link pieces 1c, 1c, and a follower on which the hanging base 1b (including the link piece 1c) and various members to be described later mounted on the hanging base 1b are mounted. The follow-up frame 4 is lifted up so that the entire weight of the frame 4 does not act on the material P to be inspected.

Here, the tension spring 3 is formed by taking into consideration the rigidity of the material P to be inspected, the total weight of the link piece 1c, the suspension base 1b, and the following frame 4 after mounting various members described later. One having a pulling force capable of reducing the weight thereof to such an extent that it does not bend is used. Further, in the illustrated example, a case where one tension spring 3 is arranged on one side is shown, but two or more tension springs may be arranged on one side as appropriate.

The hanging frame 1b is provided with pivots 4a, 4a which are swingable in a front view and which have a gate-like shape in a side view. Both lower ends thereof are directed downward in opposite directions to each other in a front view. Roller mounting plates 4b, 4b formed with protruding arms 4c, 4c that open toward the front are fixedly mounted.

The tip of the protruding arm 4c, 4c is tapered between the roller mounting plates 4b, 4b at the base end of the protruding arm 4c, 4c. A pair of left and right mounting rollers 5, 5
Is rotatably supported so that its axis is parallel to the axis of the material P to be inspected.

At the tips of the protruding arms 4c, 4c, pivoting arms 4d, 4d are rotatably supported, respectively, and the tips are in contact with and follow the lower surface of the material P to be inspected. Clamping rollers 6 ₁ and 6 ₂ , each having a rotating distal end formed in a tapered shape, are rotatably supported by a cantilever so that their axes are parallel to the axis of the material P to be inspected.

The oscillating arms 4d, 4d are always pulled upward by an appropriate number (two in the illustrated example) of tension springs 4e, 4e, and the clamping roller 6 ₁ supported at the distal end thereof. , 6 ₂ jointly inspected material P and置用roller 5,5 mounting is brought into contact with the lower surface of the test material P
Is to be gripped.

Here, the tension springs 4e, 4e include the material P to be inspected and the placing rollers 5, 5 during the inspection.
Those having a tensile force capable of maintaining the contact with the substrate are used.

Further, the swing arms 4d, 4d
As shown in FIG. 7, pins 4f, 4f are protrudingly provided. The pins 4f, 4f and the roller mounting plates 4b, 4b are attached to the ends of the piston rods of the single-acting cylinders 4g, 4g which are pivotally supported by the rollers 4b, 4b. And the U-shaped grooves of the depressed heads 4h, 4h, and swing arms 4d, 4d against the tensile force of the tension springs 4e, 4e by extending the single-acting cylinders 4g, 4g. Is pressed down so that the clamping rollers 6 ₁ and 6 ₂ can be separated from the inspection material P.

The single-acting cylinders 4g and 4g are provided with appropriate sensors for detecting the presence or absence of a material to be inspected, such as a contact type or a contact type, which is disposed above the vicinity of the upstream side in the axial direction between the placing rollers 5, 5. 7 can be operated separately based on the detection signals of the arrival of the front end of the inspection target material P and the separation of the rear end.

More specifically, the two single-acting cylinders 4
g and 4 g are extended. When the inspection material presence / absence detection sensor 7 detects that the tip of the inspection material P spirally conveyed from the direction indicated by the white arrow in FIG. 1 has passed, the input side single-acting cylinder 4g (FIG. 1). right) was Chijimicho operated in, to grip the leading end portion of the test material P in the mounting rollers 5,5 and the clamping roller 6 ₁ entry side.

[0033] Then, the exit side after the predetermined time has elapsed single acting cylinder 4g (left in FIG. 1) the Chijimicho actuated allowed by mounting the rollers 5,5 and the inlet side clamping rollers 6 ₁ and the exit side of the to grip the intermediate portion of the test material P by the clamp roller 6 _2.

Further, when the inspection material presence / absence detection sensor 7 detects the passage of the rear end of the inspection material P, the input-side single-acting cylinder 4g is extended, and after a predetermined time, the output-side single-acting cylinder 4g is extended. 4g is extended and the next inspection material P
To prepare for the inspection.

The material-to-be-inspected detection sensor 7 is mounted on the following frame 4 using a sensor mounting plate 7a having a long hole 7b drilled in the center and a bolt 7c with a head. The height position can be adjusted according to the outer diameter of P.

The above-mentioned inspection object presence / absence detection sensor 7
It is preferable to use a contact-type sensor typified by a proximity sensor from the viewpoint of preventing damage to the sensor and preventing damage to the material P to be inspected.

Furthermore, the follow-up frame 4 described above, for example, if the inspection material P is steel, ultrasonic sensor ₈₁ for detecting the axial length direction of the defect and the circumferential defect and 8
₂ is mounted so as to face the mounting rollers 5 and 5.

The ultrasonic sensors 8 ₁ and 8 ₂ are orthogonal to the roller mounting plates 4 b and 4 b using a sensor mounting plate 8 a having a long hole 8 b formed in the center and a bolt 8 c with a head. Mounting plate 4 fixed in the direction
i, 4i, so that the height position and the incident angle of the ultrasonic wave can be adjusted according to the outer diameter of the material P to be inspected.

According to the sensor follow-up device of the present invention configured as described above, the follow-up frame 4 moves from the point of arrival at the leading end to the end of the trailing end even if the material to be inspected P is spirally conveyed and its axis swings. There until detached, so gripping the object to be inspected material P by mounting the rollers 5,5 and the clamping roller 6 ₁ and / or 6 _2, to reliably track while maintaining its initial setting relation . Further, since the weight of the follower frame 4 is reduced by the tension spring 3 of the weight reducing means, the inspection target material P is not excessively bent during the inspection.

[0040] As a result, the relative positional relationship between the object to be inspected material P and the mounting roller opposed to being disposed at a position ultrasonic sensor 8 ₁ and 8 ₂ during the test period over the entire length of the test material P, initial Since the relative position of the ultrasonic wave is maintained at the set relative position and the incident angle of the ultrasonic wave to the material to be inspected P is maintained substantially constant, the inspection can be performed with high accuracy.

However, even in this case, since the material to be inspected P is spirally conveyed, when the material to be inspected P is developed in the circumferential direction, a right angle having the long side in the axial direction is provided at both ends. A triangular untested portion occurs.

However, the unexamined portions generated at both ends can be solved by movably mounting the following frame 4 on the suspension base 1b.

FIGS. 3 and 4 show an example of an apparatus configuration for this purpose. FIG. 3 is a side view showing a main part thereof, and FIG.
3 is a cross-sectional view taken along line BB of FIG. The same parts as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 3, the hanging frame on which the follower frame 4 is swingably mounted on a pivot 4a is a vertical member 1 pivotally supported on the other end of the link pieces 1c, 1c of the link mechanism 1.
b ′ and a horizontal member 1b ″, which are connected to each other via a horizontal moving mechanism 9.

The horizontal moving mechanism 9 is provided with the above-mentioned vertical member 1b '.
A guide frame 9a, which is fixedly mounted horizontally with respect to the side and has a concave shape in side view, and a vertical piece 9 of the guide frame 9a.
a ′, 9a ′, a screw shaft 9d, and a screw shaft 9
A nut member 9g meshed with a and fixedly mounted on the horizontal member 1b ", and a pulse motor 9f for rotating the screw shaft 9d forward and reverse through a timing belt 9e.

In the guide frame 9a, an elongated hole 9c is formed at the center of the guide frame 9a in a plan view to allow the nut member 9g to move in the axial direction of the screw shaft 9d. Dovetail grooves 9b, 9b are formed at both edges. Further, on both edges of the horizontal member 1b ″ in the width direction of the upper surface, dovetail groove connecting members 9h, 9h that are connected to the dovetail grooves 9b, 9b are fixedly mounted.

The horizontal moving mechanism 9 configured as described above
Is used as follows.

That is, when the tip end of the material P reaches the position facing the ultrasonic sensors 8 ₁ and 8 ₂ , the pulse motor 9 f is driven to rotate in the forward direction until the material P rotates at least once. during the pulse the loaded roller 5,5 and tracking frame 4 in a state of gripping the object to be inspected material P by the clamp roller ₆₁ and / or 6 ₂ after moved in synchronization with the moving speed of the test material P The motor 9f is temporarily stopped.

[0049] Then, a test of the intermediate portion of the test material 9 in this state, the pulse motor 9f when it reaches the position where the rear end portion of the test material P is opposed to the ultrasonic sensor ₈₁ and ₈₂ is normally rotated again, in the same manner as when the tip portion inspection until inspected material P at least one revolution, mounting rollers 5,5 and the clamping roller 6 ₁ or /
And 6 ₂ by the tracking frame 4 of the test material gripping state is moved in synchronization with the moving speed of the test material P.

Thereafter, the pulse motor 9f is driven to rotate in the reverse direction so that the follower frame 4 is moved and returned to the original position, and is prepared for the next inspection of the inspection material P.

As described above, when inspecting the front end portion and the rear end portion of the inspection target material P by the above-described horizontal movement mechanism 9, the inspection target material P follows in synchronization with the moving speed until it rotates at least once. when moving the frame 4, the inspection member of the inspected material P and the ultrasonic sensor ₈₁ and 8 ₂ 9
The positional relationship in the axial direction is kept constant. As a result, since the ultrasonic wave is incident at a predetermined angle on the entire circumference of the inspection material P at the same position in the axial direction, the above-described right triangle-shaped uninspected portion does not occur, and the inspection material P It becomes possible to inspect the entire length of P with high accuracy over the entire circumference.

The above-described sensor tracking device of the present invention has the ultrasonic sensors 8 ₁ and 8 ₂ for inspection.
However, it goes without saying that another sensor such as a sensor for eddy current detection may be used.

Next, an example of an experimental example will be described.

<Experiment Example 1> In the experiment, the total weight of the following frame after mounting various members was 17 kg as a sensor following device.
The sensor follower of the present invention shown in FIGS. 1 and 2, the tension spring 3 of the weight reducing means, the rollers 6 ₁ and 6 ₂ for clamping and the accompanying members for operating them are not provided. The test was performed using a conventional sensor follow-up device with a weight of 1.5 kg which did not cause any bending of the material to be inspected.

The material to be inspected has an outer diameter of 60 mm,
An eccentric test material having a thickness of 3 mm and a length of 3 mm made of carbon steel, the center of the center of which is eccentric to the center of both ends by 2.5 mm, and the amount of bending was set to 1.9 mm per meter. Two types of bending test materials were used.

Then, the distance (fluctuation amount) between the separation and detachment of the mounting roller 5 from the test material was measured, and the followability of the follower frames of both devices was examined.

As a test condition, the test material was rotated at 200 rpm without being spirally conveyed. Further, in the sensor following device of the present invention, the total weight of the following frame 4 acting on the test material and the clamping force by the clamping rollers 6 ₁ and 6 ₂ are variously changed by using the tension springs 3 and 4 e having different stretching forces. Was.

FIG. 5 shows the result. The numerical values in the drawings show the clamping force by the clamping roller 6 _1, 6 _2.

As is clear from the results shown in FIG. 5, in the conventional sensor follow-up device, the variation was 0.75 mm in any of the test materials.

On the other hand, in the sensor follow-up device of the present invention, when the entire weight of the follow-up frame 4 is applied to the test material without mounting the tension springs 3 and 4e, the fluctuation amount is 0 (zero). The properties themselves were good. However, in an actual inspection, a material to be inspected was bent and good inspection accuracy could not be obtained.

When the weight acting on the test material is reduced by mounting only the tension spring 3, the amount of variation increases as the weight decreases, and good inspection accuracy cannot be obtained in actual inspection.

On the other hand, when the tension springs 3 and 4e are mounted, the weight acting on the test material is 3 kg or less, and the clamping force by the clamping rollers 6 ₁ and 6 ₂ is about 1 kg, the fluctuation amount becomes The maximum was about 0.1 mm. Also, in the actual inspection, the inspection target material did not bend, and good inspection accuracy was obtained.

<Experimental Example 2> Next, using the apparatus of the present invention shown in FIG. 3 and FIG. The test was conducted using a straight steel pipe having the same dimensions as that used in Experimental Example 1 and having an artificial defect in the axial direction of the pipe with a length of 10 mm from the pipe end at one point in the circumferential direction of the pipe end. I went to the target.

The experimental conditions were as follows: the test material was fed in the axial direction at a feed rate of 3.8 mm / min and a feed pitch of 10 mm / min.
The sheet was conveyed spirally in rev, and the follow-up frame 4 was moved 10 mm in synchronization with the feed speed of the material to be tested, and was carried out 10 times in each of two cases.

As a result, when the tracking frame 4 was not moved, no artificial defect could be detected five out of ten times. On the other hand, when the follower frame 4 was moved synchronously with the feed speed of the test material, an artificial defect could be detected ten times.

[0066]

According to the sensor tracking device of the present invention, the sensor for inspection can be made to follow the material to be inspected almost completely without bending the material to be inspected, so that a highly accurate inspection is possible. . In addition, since the follow-up frame can be synchronously moved at the moving speed at the time of inspecting the edge of the material to be inspected, there is no uninspected portion at both ends, and the entire circumference of the material to be inspected can be inspected with high accuracy. Is possible.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a sensor follow-up device according to the present invention.

FIG. 2 is a front view taken along line AA of FIG. 1;

FIG. 3 is a side view showing a main part of another sensor tracking device according to the present invention.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a diagram showing an example of an experimental result.

[Explanation of symbols]

1: Link mechanism, 2: Height position adjustment means, 2a: Headed bolt, 2b: Head, 2c: Nut, 3: Tension spring (weight reduction means), 4: Following frame, 4a: Axle support, 4b: 4c: projecting arm, 4d: swing arm, 4e: tension spring, 4f: pin, 4g: single-acting cylinder, 4h: push-down head, 4i: mounting plate, 5: mounting roller, 6 ₁ , 6 _2: clamping roller 7: inspected material presence or absence detection sensor, 8 _1, 8 _2: ultrasonic sensors, 7a, 8a: sensor mounting plate 7b, 8b: long hole, 7c, 8c: tap bolt, 9 9a: guide frame, 9b: dovetail groove, 9c: long hole, 9d: screw shaft, 9e: timing belt, 9f: pulse motor, 9g: nut member, 9h: dovetail joint member.

Claims (2)

[Claims] An apparatus for non-destructively inspecting an inspection material having a circular cross section conveyed spirally in the axial direction, wherein the sensor tracking device is provided with a predetermined interval in a direction orthogonal to an axis of the inspection material. A pair of mounting rollers that are arranged opposite to each other, are placed on the upper surface of the material to be inspected, and rotate in contact with and follow the material to be inspected in a direction opposite to the material to be inspected, and are disposed before and after in the axial direction of the mounting roller. A pair of clamping rollers that respectively move toward and away from the lower surface of the inspection target material to elastically press and grip the inspection target material, and a sensor disposed at a position opposed to the pair of mounting rollers. A sensor follow-up device, wherein the follow-up frame provided is suspended from a vertically movable link mechanism having weight reducing means and height position adjusting means. 2. The sensor follow-up device according to claim 1, wherein the follow-up frame is mounted on a link mechanism that can move up and down so as to follow the transport speed of the material to be inspected.