JPH0555060U - Vertical small diameter pipe flaw detector - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] A flaw detection device for upright small-diameter pipes, which is equipped with a sensor at the back of the pipe to perform flaw detection with high accuracy. [Structure] A fixed frame 11 placed on an upper opening of a small-diameter pipe B in an upright state, an elevating means for vertically moving a sensor unit 10 and arranging it at an inspection position, and a fixed frame 1.
1 is provided with a slide frame 13 which is vertically moved by a slide mechanism 14, a connecting shaft 15 which connects the slide frame 13 and the sensor unit 10, and a turning means 16 which horizontally turns the sensor unit 10. The sensor unit 10 is moved in the circumferential direction and the vertical direction of the pipe by the slide mechanism 14 and the turning means 16 to perform flaw detection inspection.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a flaw detector for an upright small diameter pipe, and more particularly to a technique for inspecting a welded portion from the inside of an upright small diameter pipe.

[0002]

[Prior Art]

 One type of nuclear reactor is a high temperature gas reactor that uses helium as a heat medium. In the heat exchanger X used in this high temperature gas furnace, as shown in FIG. 4, a gas outlet inner cylinder (small diameter pipe) B in an upright state is arranged inside a cylindrical container. The gas outlet inner cylinder B merges the secondary helium gas, which has undergone heat exchange through a plurality of helical coils 1 arranged in a spiral shape, at the lower part and discharges it from the upper part of the heat exchanger X. Is a cylindrical pipe having a length substantially equal to the entire length of the heat exchanger X. The gas outlet inner cylinder B has an opening 2 at the upper end exposed to the outside of the heat exchanger X, and a lower end formed by welding a lid member 3 to form a closed shape.

A merging portion 4 for merging the secondary helium gas described above is provided on the lid member 3. The confluence portion 4 has a complicated shape in which a plurality of helical coils 1 made of thin tubes are gathered in one tubular member 5, and the helical coil 1 and the tubular member 5 are integrally formed due to a problem of strength. The method of doing is adopted. Therefore, this merging portion 4 also constitutes a part of the gas outlet inner cylinder B by being welded similarly to the lid member 3.

[0004]

[Problems to be solved by the device]

 By the way, since the gas outlet inner cylinder B is exposed to high-temperature helium gas, it is necessary to confirm the soundness of the above-mentioned welded portion S or the like periodically or as needed. However, the total length of the heat exchanger X is set to about ten and several meters in order to lengthen the heat exchange flow path, and the diameter thereof is often kept small in order to save space. Therefore, the gas outlet inner cylinder B is a pipe having a small diameter of about 10 meters and a diameter of about 30 centimeters, and the above-mentioned welded portion S to be inspected is located at the lower part of the gas outlet inner cylinder B. Therefore, it was difficult to confirm its soundness.

The present invention has been made in view of the above problems, and facilitates the work of confirming the soundness of a welded portion located at the inner part of an upright small-diameter pipe, and performs highly accurate flaw detection inspection. The purpose is to do it and to make the device compact.

[0006]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention is an apparatus for performing a flaw detection inspection of a welded part on the inner surface of a pipe by inserting a sensor part from an upper opening of a small-diameter pipe in an upright state. A fixed frame placed on the opening end, an elevating means arranged on the fixed frame to move the above-mentioned sensor unit in the vertical direction to place it at the inspection position, and a vertical movement by a slide mechanism mounted on the fixed frame. A slide frame, a connecting shaft arranged between the slide frame and the sensor unit for connecting the sensor unit to the slide frame in a horizontally rotatable manner, and a swinging unit connected to the sensor unit for horizontally swinging the sensor unit. The present invention provides a flaw detection device for an upright small-diameter pipe having a configuration including.

[0007]

[Action]

 In the flaw detector according to the present invention, the fixing frame is fixed to the upper opening of the small diameter pipe in the upright state, the sensor part is inserted into the pipe, and the elevating means arranged on the fixed frame is operated. The sensor part to the inspection position on the inner surface of the pipe. During this hoisting work, the slide frame attached to the fixed frame and the sensor section are connected by the connecting shaft. Since this connecting shaft connects the sensor unit to the slide frame so as to be horizontally rotatable, the sensor unit is horizontally rotated with respect to the slide frame by operating the rotating means. Further, when the slide frame is moved up and down with respect to the fixed frame by operating the slide mechanism, the sensor unit connected to the slide frame by the connecting shaft is also moved up and down near the inspection position.

[0008]

【Example】

 An embodiment of a flaw detection device for an upright small diameter pipe according to the present invention will be described below with reference to FIGS. 1 to 3.

In these drawings, reference numeral Y is a flaw detector, reference numeral B is a gas outlet inner cylinder (small-diameter pipe), reference numeral S is a welded portion, reference numeral 10 is a sensor portion, reference numeral 11 is a fixed frame, and reference numeral 12 is a lifting means. Reference numeral 13 is a slide frame, reference numeral 14 is a slide mechanism, reference numeral 15 is a connecting shaft, and reference numeral 16 is a turning means.

The sensor unit 10 includes a disk-shaped sensor frame 10a arranged horizontally in the gas outlet inner cylinder B, and an ultrasonic probe arranged on the outer periphery of the sensor frame 10a and in contact with the inner surface of the pipe. 10b, and the ultrasonic probe 10b, the sensor frame 10a and three guide balls 10c arranged at positions that divide the outer circumference into four equal parts. The guide ball 10c is urged toward the inner surface of the gas outlet inner cylinder B by a resilient means such as a spring, and presses the inner surface of the gas outlet inner cylinder B in each direction to move the sensor frame 10a to the gas outlet inner cylinder B. The ultrasonic probe 10b is set in the center position and is held in close contact with the inner surface of the gas outlet inner cylinder B.

At the center of the upper surface of the sensor frame 10a, a convex portion 10d having a male screw on the outer periphery is provided. The convex portion 10d is formed in the same shape as the female side connecting portion of the connecting shaft described later.

The fixed frame 11 includes an annular fixed flange 11a mounted on the upper end of the gas outlet inner cylinder B, four columns 11b extending upward from the fixed flange 11a, and an upper portion of the column 11b. It has a top plate 11c to be fixed, and is formed into a cage-shaped frame structure as a whole.

As shown in FIG. 2, the elevating means 12 includes four sheaves 12a rotatably attached to the lower surface of the top plate 11c of the fixed frame 11 in a vertical plane, and the sheaves 12a interlocked with each other. The interlocking shaft 12b and the interlocking gear 12c are provided, a handle 12d for rotating the pulley 12a, and a wire rope 12e wound around the pulley 12a.

The slide frame 13 includes a ball screw 13a and a spline shaft 13b that penetrate the top plate 11c of the fixed frame 11, and an upper connecting plate 13c and a lower connecting plate that connect the ball screw 13a and the spline shaft 13b in a parallel state. And a plate 13d.

The connecting plates 13c and 13d are fixed to both ends of the ball screw 13a, and rotatably support the spline shaft 13b via bearings 13e. The spline shaft 13b is attached so as to penetrate the lower connecting plate 13d, and a drive gear described later is fixed to the lower end of the spline shaft 13b.

The slide mechanism 14 includes a slide motor 14a attached to the upper surface of the fixed frame 10, a worm gear 14b rotated by the slide motor 14a, and a wheel gear 14c meshing with the worm gear 14b. A ball nut 14d fixed to the wheel gear 14c and screwed into the ball screw 13a of the slide frame 13 is provided.

The connecting shaft 15 is a rod-shaped shaft having a male side connecting portion 15a and a female side connecting portion 15b at both ends. The male side connecting portion 15a has a cylindrical shape having a key 15c at the shaft end, and the female side connecting portion 15b has a fitting hole 15d into which the male side connecting portion 15a can be fitted. .. By thus forming both ends of the connecting shaft 15 in such a manner that they can be connected to each other, it is possible to connect a plurality of connecting shafts 15 in series, and the connected connecting shafts 15 are connected and fixed. It is adapted to be fixed by means 15e.

The connecting and fixing means 15e is provided on the outer peripheral surface of the female-side connecting portion 15b, and a fixing portion 15f provided on the male-side connecting portion 15a, a fixing ring 15g engaged with the flange portion 15f and having a female screw. And a male screw 15h screwed to the fixing ring 15g.

The turning means 16 includes a turning motor 16a attached to the upper surface of the fixed frame 10, a worm gear 16b rotated by the turning motor 16a, and a wheel gear 16c meshing with the worm gear 16b. A spline nut 16d fixed to the wheel gear 16c and inserted through the spline shaft 13b of the elevating frame 13, a drive gear 16e fixed to the lower end of the spline shaft 13b, and a turning gear 16f meshing with the drive gear 16e are provided. It is equipped.

The swivel gear 16f is rotatably supported on the lower surface of the central portion (the central portion of the fixed frame 11) of the lower connecting plate 13d, and the male side connecting portion 15a of the connecting shaft 15 is attached to the lower end thereof. A connecting and fixing means 15e is provided which has a connecting convex portion 16g having the same shape as that of and which holds the connecting shaft 15 after being connected so as not to fall off.

In the flaw detector Y configured as described above, the fixed frame 11 is placed in the upper opening 2 of the gas outlet inner cylinder B, and the sensor frame 10 a is placed in the horizontal state inside the gas outlet inner cylinder B. Then, the handle 12d of the elevating means 12 is operated to suspend the inside of the gas outlet inner cylinder B.

In the lifting operation of the flaw detector Y, since the four pulleys 12a are interlocked by operating the handle 12d, the wire ropes 12e are simultaneously drawn out and the sensor frame 10a is kept horizontal. As it is, it will be hung down inside the gas outlet inner cylinder B.

Next, when the distance between the connecting convex portion 16g of the turning gear 16f provided at the lower end of the slide frame 13 and the convex portion 10d of the sensor frame 10a is widened to the distance at which the connecting shaft 15 can be inserted, The connecting shaft 15 is fixed to the convex portion 10d of the sensor frame 10a. Then, the operation of suspending the sensor frame 10a again and connecting the connecting shafts 15 in series is repeated, and when the ultrasonic probe 10b attached to the sensor frame 10a reaches the vicinity of the weld S, the connection is finally made. The female side connecting portion 15b of the connecting shaft 15 is fitted into the connecting convex portion 16g of the turning gear 16f, and the fixing ring 15g is screwed into the male screw 15h of the female side connecting portion 15b to form the connecting convex portion 16g and the connecting shaft 15. To fix.

After the above work, the handle 12d of the elevating means 12 is further rotated to completely loosen the wire rope 12e, and the turning means 16 is actuated to operate the gas outlet inner cylinder B of the ultrasonic probe 10b. The inspection position in the circumferential direction is set, and the inspection position in the vertical direction of the ultrasonic probe 10b is set by the operation of the slide mechanism 14.

To set the inspection position in the circumferential direction, the turning motor 16a is operated, the spline shaft 13b is rotated via the worm gear 16b and the wheel gear 16c, and the drive gear 16e and the turning gear 16f at the lower end of the spline shaft 13b are rotated. It is performed by rotating the sensor frame 10a via the connecting shaft 15.

To set the inspection position in the vertical direction, the slide motor 14a is actuated, the rotational force is transmitted to the ball nut 14d via the worm gear 14b and the wheel gear 14c, and the ball nut 14d is screwed into the ball screw. It is performed by converting the vertical movement of the slide frame 13a into a vertical movement of the slide frame 13a and moving the slide frame 10a in the vertical direction.

In these setting operations, since the ultrasonic probe 10b is pressed against the inner surface of the gas outlet inner cylinder B by the guide ball 10c, the ultrasonic probe 10b absorbs the influence of the unevenness of the surface, etc. Maintain a good contact state.

In this way, when performing the ultrasonic flaw detection inspection, the position of the ultrasonic probe 10b is set in the circumferential direction and the vertical direction of the gas outlet inner cylinder B by the operation of the turning means 16 and the sliding mechanism 14. The ultrasonic probe 10b is operated while moving in the direction.

The work of pulling up the sensor frame 10a after the ultrasonic flaw detection is performed by sequentially removing the connecting shaft 15 and rotating the handle 12d of the elevating means 12 in the opposite direction to wind up the wire rope 12e. ..

The following techniques can be adopted in the flaw detector Y according to the present invention. (1) Instead of the sensor frame 10a to which the ultrasonic probe 10b of the sensor unit 10 is attached, a small TV camera or the like is used. (2) The swiveling means 16 is connected to the connecting shaft 15 via the worm gear 16b, the wheel gear 16c, the spline nut 16d, the spline shaft 13c, the drive gear 16e, and the swiveling gear 16f by the swiveling motor 16a attached to the fixed frame 11. Although it is supposed to rotate horizontally, instead of this, the rotating motor is fixed to the lower connecting plate 13d of the slide frame 13, and the connecting shaft 15 is directly connected to the rotating motor. (3) The ball nut 14d is rotated to move the ball screw 13a in the vertical direction, but instead, the ball nut is fixed to the slide frame 13 and the ball screw is rotated to move the slide frame 13 up and down. ..

[0031]

[Effect of the device]

 As described above, according to the flaw detection apparatus of the present invention, the fixed frame mounted on the upper opening of the small-diameter pipe in the upright state, and the lifting / lowering unit for vertically moving the sensor unit to place it at the inspection position. Means, a slide frame that is vertically moved to the fixed frame by a slide mechanism, a connecting shaft that connects the slide frame and the sensor unit, and a turning unit that horizontally turns the sensor unit. The following effects are achieved. (1) Since the sensor unit hung from the upper part of the pipe is operated by the slide mechanism and the turning means, it is possible to facilitate the work of confirming the soundness of the welded part located in the deep part of the small diameter pipe. (2) It is possible to accurately set the position and move the sensor unit by the turning means and the slide mechanism, and perform highly accurate flaw detection inspection. (3) At the time of inspection, the slide frame and the sensor unit are connected by the connecting shaft, and the connecting shaft is removed after the inspection is completed, so that the flaw detector can be made compact. (4) Since all the driving parts are arranged above the small-diameter pipe, there is an advantage that maintenance is easy. As a result, it is not necessary to feed the drive cable into the pipe, so that the cable does not interfere with the operation of the sensor unit.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of a flaw detection device for an upright small-diameter pipe according to the present invention.

FIG. 2 is a cross-sectional view of the flaw detector of FIG. 1 taken along a chain line AA.

FIG. 3 is a detailed view showing a connecting shaft of the flaw detection apparatus of FIG.

FIG. 4 is a front sectional view showing a heat exchanger used in a gas furnace.

[Explanation of symbols]

 B Gas outlet inner cylinder (small-diameter pipe) X Heat exchanger Y Flaw detector S Weld 1 Helical coil 2 Upper opening 3 Lid member 4 Merging part 5 Cylindrical member 10 Sensor part 10a Sensor frame 10b Ultrasonic probe 10c Guide Ball 10d Convex part 11 Fixed frame 11a Fixed flange 11b Strut 11c Top plate 12 Lifting means 12a Pulley 12b Interlocking shaft 12c Interlocking gear 12d Handle 12e Wire rope 13 Slide frame 13a Ball screw 13b Spline shaft 13c Upper connecting plate 13d Lower connecting plate 14e Slide mechanism 14a Motor for sliding 14b ・ 16b Worm gear 14c ・ 16c Wheel gear 14d Ball nut 15 Connecting shaft 15a Male side connecting part 15b Female side connecting part 15c Key 15d Fitting hole 15e Connecting solid Means 15f flange portion 15g fixing ring 15h male screw 16 turning means 16a swing motor 16d spline nut 16e driving gear 16f turning gear 16g connecting protrusions

Claims (1)

[Scope of utility model registration request] 1. A device for performing a flaw detection inspection of a welded portion on an inner surface of a pipe by inserting a sensor portion from an upper opening of a small-diameter pipe in an upright state, and a fixed frame arranged in the upper opening of the pipe, Elevating means arranged on a fixed frame to move the sensor section in the vertical direction to be placed at the inspection position, a slide frame mounted on the fixed frame and moved in the vertical direction by a slide mechanism, the slide frame and the sensor section. A vertical axis small-diameter pipe, which comprises a connecting shaft that is connected between the sensor frame and the slide frame so that the sensor frame can be horizontally swiveled, and swivel means that is connected to the sensor unit and horizontally swivels the sensor unit. apparatus.