JP3054040B2 - Weld leak detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a welding method for detecting a leak of a welded portion arranged in a narrow place, such as an interphase flange of a three-phase split on-site transformer, by an intermediate method. The present invention relates to a leak detection device.

[0002]

2. Description of the Related Art FIG. 6 shows, for example, Japanese Patent Application Laid-Open No. 57-194328.
FIG. 1 is a cross-sectional view showing a conventional method for detecting a leak at a welded portion shown in Japanese Patent Application Laid-Open Publication No. H11-209,837. In the drawing, reference numeral 1 denotes a butt-welded test object, 2 denotes a welded portion of the test object 1 subjected to a leak test,
Reference numeral 3 denotes bromophenol as a reagent for detecting ammonia gas, which is applied to the surface 1a side of the test object 1 so as to cover the welded portion 2, and reference numerals 4a and 4b denote a predetermined interval along the welded portion 2. And an adhesive tape adhered to the surface 1b side of the test object 1.

[0003] 5a and 5b are double-sided tapes having an adhesive property on both sides adhered on both adhesive tapes 4a and 4b, and 6 is affixed to both ends across these double-sided tapes 5a and 5b to cover the welded portion 2. Belt-shaped flexible sheets, 7a and 7b are adhesive tapes applied to hold both ends of the flexible sheet 6, and 8 is formed between the back surface 1b of the test object 1 and the flexible sheet 6. The passage is connected to gas supply means for supplying ammonia gas as a leak test fluid (not shown).

Next, a test method will be described. First, an ammonia gas is supplied from a gas supply unit into the passage 8 formed by the flexible sheet 6, and is filled under pressure. At this time, if there is a defect in the weld 2, the bromophenol 3 is applied to the surface 1 a side, so that the ammonia in the passage 8 leaks through the defect and the bromophenol 3
It dissolves in and shows a characteristic color reaction of purple blue. A leak of ammonia gas is detected by this color reaction, and a defect in the welded portion 2 is detected.

[0005]

As described above, the conventional method of detecting a leak at a welded portion is narrow because the work of attaching a flexible sheet to the welded portion with an adhesive tape or applying a reagent is required. Since it is very difficult to detect leaks at appropriate locations, and since both ends of the flexible sheet forming the ammonia gas passage for the leak test are sealed with adhesive tape,
It is difficult to seal the gas at a high pressure, so that the detection accuracy is low. In addition, in the appearance inspection, there is a problem that human eyes cannot reach and only inspection with a mirror or the like can be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and makes it easy to detect a leak in a narrow place, and makes it possible to apply a high-pressure leak test gas to detect a leak. Accuracy can be improved,
Another object of the present invention is to provide a leak detecting device for a welded portion that can prevent the influence on the surroundings even if a leak test gas leaks, and that can easily perform an external inspection. It is.

[0007]

According to a first aspect of the present invention, there is provided a leak detecting device for a welded portion having a flange surface formed in a dish-like shape and having an annular groove formed around the opening so as to be evacuated. Enclosure case, case pressing means for pressing the flange surface of the enclosure case to the back side of the welding bead of the member to be welded to form a compartment between the member to be welded and the enclosure case,
It is provided with a gas filling means for filling a gas at a predetermined pressure into the compartment, and a gas detecting means provided to face the welding bead.

According to a second aspect of the present invention, there is provided a leak detecting device for a welded portion, comprising: a sealed case formed in a dish shape and having a flange surface around an opening; Case pressing means for pressing the back side of the member to form a compartment between the member to be welded and the enclosure, gas filling means for filling a gas at a predetermined pressure into the compartment, and facing the welding bead, respectively. It is provided with gas detection means provided and shape detection means for detecting the shape of the weld bead.

According to a third aspect of the present invention, there is provided a leak detecting device for a welded portion according to the second aspect, wherein an annular groove is formed on the flange surface of the enclosure case along the flange surface and the inside of the groove can be evacuated. It was made.

According to a fourth aspect of the present invention, there is provided a leak detecting device for a welded portion according to any one of the first to third aspects, wherein the enclosing case is formed of a hard elastic member.

Further , according to a fifth aspect of the present invention, there is provided a weld portion
In the first aspect of the present invention, the gas detector detects the gas detecting means.
It is designed to run along the contact bead.

Further, according to a sixth aspect of the present invention, there is provided a weld portion
The gas detector comprises a gas detector and a gas detector.
And run the shape detection means along the weld bead.
It is a thing.

Further, according to a seventh aspect of the present invention, there is provided a weld portion
The apparatus for detecting a work mark according to any one of claims 1 to 6,
The weld between the inter-phase flanges of the three-phase split field assembly transformer
It is applied to

[0014]

According to a first aspect of the present invention, there is provided a leak detecting device for a welded portion, wherein a flange surface is pressed by a case pressing means toward a back surface of a weld bead of a member to be welded.
With enclosing a high pressure gas by the gas filled unit detects a gas leak weld by a gas detecting means, sealing
Gas leaking from the inside of the case is transferred to the flange surface of the sealed case.
Captured in the annular groove formed in
I do.

Further, according to a second aspect of the present invention, there is provided a leak detecting device for a welded portion, wherein a high pressure is applied by a gas sealing means into a sealing case whose flange surface is pressed against the back side of a weld bead of a member to be welded by a case pressing means. The gas is sealed, the gas detecting means detects gas leaking from the welded portion, and the shape detecting means detects the external shape of the weld bead.

According to a third aspect of the present invention, there is provided an apparatus for detecting a leak at a welded portion, wherein gas leaking from an enclosed case is captured in an annular groove formed on a flange surface of the enclosed case, and is recovered by evacuation. I do.

According to a fourth aspect of the present invention, there is provided a leak detecting device for a welded portion, wherein the sealing case is formed of a hard elastic member, so that the sealing member is not airtightly provided on the back side of the member to be welded. Pressed.

Further , according to claim 5 of the present invention,
The leak detector uses gas detection means along the weld bead.
The running speed increases the leak detection speed and
Improve the rate.

[0019] Further, the leak detection device of the welding unit in the sixth aspect of the invention, by traveling along the gas detection means and shape detection means to the weld bead, to improve the working efficiency by increasing the leak detection speed .

A leak detecting device for a welded portion according to a seventh aspect of the present invention detects a leak at a welded portion between inter-phase flanges of a three-phase split on-site transformer.

[0021]

[Embodiment 1] Hereinafter, an embodiment of the present invention will be described with reference to the drawings by applying the present invention to a weld between inter-phase flanges of a three-phase split field assembly transformer. FIG. 1 is a diagram showing a schematic configuration of a leak detecting device for a welded portion according to a first embodiment of the present invention. FIG. 2 is a diagram showing a configuration of a welded portion between inter-phase flanges of the three-phase split on-site transformer shown in FIG. 3 is a front view showing the structure of the case pressing means shown in FIG. 1, FIG. 4 is a plan view showing the details of the sealed case shown in FIG. 1, a front view and a side view, and FIG. It is sectional drawing which shows the state which pressed the welding bead back surface side of the welding member.

Generally, as shown in FIG. 2, a three-phase split on-site transformer includes windings of each phase (not shown) connected to each central tank 9.
a, 9b, 9c and lower tanks 10a, 10b, 10
c, transported to the site, and welded and integrated between the interphase flanges 11a, 11b, 11c respectively fixed to the upper portions of the lower tanks 10a, 10b, 10c, and then integrated into the tanks 9a, 9b, 9c, 10a, 10
b, 10c are removed, an iron core is mounted between the windings, combined and housed in a main tank (not shown), and the insulating medium is sealed to complete the on-site assembly.

Therefore, the interphase flanges 11a, 11
Each of the welded portions 12a and 12b formed by welding between b and 11c is required to be airtight. However, once stored in the tank, the welded portion 12a,
If a leak is detected in 12b, the repair work becomes very difficult. Therefore, as shown in FIG.
Immediately after the welding between 11b and 11c has been performed, the leak detection of the welded portions 12a, 12b and 12c is performed under extremely narrow and difficult conditions.

In the figure, reference numeral 13 denotes an enclosing case formed in a dish shape. As shown in FIG. 4, a flange surface 13a is formed around the upper opening, and an exhaust port 13b is formed along the flange surface 13a. An annular groove 13c is provided, and a gas filling port 13d is provided at the bottom. 14 is a vacuum pump connected to an exhaust port 13b via a valve 14a, and 15 is a
This is a gas cylinder as gas filling means connected via 5a and 15b.

Reference numeral 16 denotes a gas detection probe serving as gas detection means disposed above and facing the welding bead of the welding portion 12a, and is connected to the gas detector 17. Reference numeral 18 denotes a visual sensor as a shape detecting means which is disposed above the welding bead of the welding portion 12a and faces the same as the gas detecting probe 16, and is connected to a video monitor 19. The gas detection probe 16 and the visual sensor 18
Is held by an automatic traveling device (not shown), and is disposed so as to be able to travel along the welding bead.

Numeral 20 denotes a case pressing means for holding the enclosing case 13 and pressing the back face of the weld bead of the interphase flanges 11a and 11b via the packing 26 as shown in FIG. 5, and a frame 21 as shown in FIG. A plurality of hydraulic cylinders 22 are mounted on the upper side, and guide rollers 23 for guiding the case pressing means 20 between the lower tanks 10a and 10b on the side surfaces of the frame 21 using the side surfaces of the lower tanks 10a and 10b as guides, In addition, moving rollers 24 for facilitating the movement of the case pressing means 20 are provided on the lower surface of the frame 21, respectively. Reference numeral 25 denotes a hydraulic unit that is connected to each hydraulic cylinder 22 and supplies a predetermined driving pressure. Reference numeral 27 denotes a compartment formed between the inter-flanges 11a and 11b and the enclosing case 13.

Next, the operation of the leak detecting device for a welded portion constructed as described above will be described. First, while inserting the case pressing means 20 between the lower tanks 10a and 10b via the guide roller 23 and the moving roller 24,
Above the weld 12a of the interphase flanges 11a, 11b,
An automatic traveling device (not shown) such that the gas detection probe 16 and the visual sensor 18 respectively face the welding bead.
Attach. Next, the hydraulic unit 25 is driven to supply a driving pressure to each of the hydraulic cylinders 22 so that the enclosing case 1
3 is pressed against the back surface of the welded portion 12a of the inter-phase flanges 11a and 11b via a packing 26 to form a compartment 27.

The gas cylinder 1 is placed in the compartment 27.
After supplying gas through the gas filling port 13d from 5 and maintaining the inside of the compartment 27 at a predetermined pressure, the automatic traveling device (not shown) is moved along the welding bead at a speed of 2 to 3 cm / sec. The gas detection probe 16 and the visual sensor 1
By 8, the gas leaking from the welded portion 12 a and the shape of the weld bead are monitored, and if there is any gas leak or abnormal shape, it is detected by the gas detector 17 and the video monitor 19. On the other hand, when the gas sealed in the compartment 27 leaks from the packing 26, the gas is captured in an annular groove formed around the gas and is collected by being evacuated by the vacuum pump 14.

As described above, according to the first embodiment, the configuration described above facilitates the detection of leaks at narrow locations, and the use of high-pressure gas is possible by using the sealed case 13. The accuracy of leak detection can be improved, and the shape of the weld bead can be monitored by the visual sensor 18, thereby making it possible to foresee where a leak is likely to occur. Can be improved and the sealed case 13
By forming an annular groove 13c on the flange surface 13a and evacuating it, it is possible to prevent adverse effects such as gas leaking from the inside of the compartment 27 to the outside and adversely affecting the automatic traveling. By moving the gas detection probe 16 and the visual sensor 18 by the device, it is possible to increase the leak detection speed and improve the work efficiency.

Embodiment 2 FIG. In the first embodiment, airtightness is maintained by interposing the packing 26 between the enclosing case 13 and the inter-phase flanges 11a and 11b. However, the enclosing case 13 itself is made of a hard elastic member. If it is formed, it is possible to sufficiently maintain airtightness without interposing the packing 26 or the like.

Embodiment 3 FIG. Further, in each of the above embodiments, the case where the present invention is applied to the welding portion between the inter-phase flanges of the three-phase split on-site assembling transformer has been described.However, the present invention is not limited to this, and the welding beads are disposed at narrow locations. It is needless to say that the present invention can be applied as long as it has a welded portion, and the same effects as those of the above embodiments can be exerted.

[0032]

As described above, according to the first aspect of the present invention, the ring formed in a dish shape and capable of evacuating around the opening is provided.
An enclosing case having a flange surface with a groove formed therein ,
Case pressing means for pressing the flange surface of the enclosing case against the back side of the weld bead of the member to be welded to form a compartment between the member to be welded and the enclosing case, and enclosing gas at a predetermined pressure in the compartment. Since gas filling means and gas detecting means arranged opposite to the welding bead are provided, it is easy to detect leaks in narrow places and to apply a high-pressure leak test gas. It is possible to provide a leak detecting device for a welded portion capable of improving the leak detection accuracy and recovering leaked gas .

According to a second aspect of the present invention, an enclosing case formed in a dish shape and having a flange surface around the opening, and the flange surface of the enclosing case is pressed against the back side of the weld bead of the member to be welded. Case pressing means for forming a compartment between the member to be welded and the enclosing case, gas filling means for filling a gas at a predetermined pressure into the compartment, and gas detecting means disposed opposite to the welding bead. Means and a shape detecting means for detecting the shape of the weld bead, thereby facilitating the detection of leaks in narrow locations and enabling the use of a high-pressure leak test gas to improve the leak detection accuracy. Of course it is possible to improve,
It is possible to provide a leak detecting device for a welded portion capable of predicting a location where a leak is likely to occur in the future.

According to claim 3 of the present invention,
In 2 , the annular groove is formed on the flange surface of the enclosure case along the flange surface and the inside of the groove can be evacuated, so that it is easy to detect leaks in narrow places and to use a high-pressure leak test gas. Not only to improve the accuracy of leak detection, but also to provide a weld leak detection device capable of capturing and recovering gas leaked from the sealed case. can do.

According to a fourth aspect of the present invention, in any one of the first to third aspects, since the enclosing case is formed of a hard elastic member, it is easy to detect a leak in a narrow place. It is possible not only to improve the leak detection accuracy by applying a high-pressure leak test gas, but also to press tightly without interposing a seal member on the back side of the member to be welded. It is possible to provide a leak detecting device for a welded portion capable of performing the above.

According to claim 5 of the present invention, claim
In 1, the gas detection means is moved along the welding bead.
To easily detect leaks in narrow places
And high pressure gas for leak test can be applied.
To improve the accuracy of leak detection.
Of course, the leak detection speed is increased
Leak detection device for welds that can improve work efficiency
Can be provided.

According to claim 6 of the present invention,
In either of the two, it can run along the welding bid
This makes it easy to detect leaks in narrow places.
And high pressure leak test gas can be applied.
In this way, it is possible to improve the leak detection accuracy
Of course, we increased the leak detection speed and
Leak detection device that can improve the welding rate
Can be provided.

According to claim 7 of the present invention,
In any of 1 to 6, three-phase split on-site assembly transformer
Applied to leak detection of welds between the inter-apparatus flanges
In addition to facilitating leak detection in narrow places,
Make it possible to apply high-pressure leak test gas and
Of course, it is possible to improve
That is, when it is earlier than the pressure test when assembling the entire transformer
Leak detection for welds that can perform leak detection at points
An apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a leak detecting device for a welded portion in Embodiment 1 of the present invention.

FIG. 2 is a diagram showing a configuration of a weld between inter-phase flanges of the three-phase split on-site assembly transformer shown in FIG. 1;

FIG. 3 is a front view illustrating a configuration of a case pressing unit illustrated in FIG. 1;

FIG. 4 shows details of the sealed case shown in FIG. 1;
(A) is a plan view, (B) is a front view, and (C) is a side view.

FIG. 5 is a cross-sectional view showing a state where the sealing case shown in FIG. 4 is pressed against the back side of the welding bead of the member to be welded.

FIG. 6 is a cross-sectional view illustrating a conventional method for detecting a leak at a welded portion.

[Explanation of symbols]

9a-9c Middle tank, 10a-10c Lower tank, 11a-11c Interphase flange, 12a, 12b
Welded part, 13 sealed case, 14 vacuum pump, 15
Gas cylinder (gas filling means), 16 gas detection probe
(Gas detecting means), 18 visual sensor (shape detecting means), 2
0 Case pressing means, 27 compartments.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-49-88581 (JP, A) JP-A-1-224634 (JP, A) Full-scale operation Showa 61-15536 (JP, U) Real-time operation Showa 49- 13686 (JP, U) Shokai Sho 61-72657 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 3/02 G01M 3/12 G01M 3/20

Claims (7)

(57) [Claims] 1. A vacuum is drawn around an opening formed in a dish shape.
An enclosing case having a flange surface on which a possible annular groove is formed, and pressing the flange surface of the enclosing case against the back side of the welding bead of the member to be welded to partition between the member to be welded and the enclosing case. Welding comprising: a case pressing means for forming a chamber; a gas filling means for filling a gas at a predetermined pressure into the compartment; and a gas detecting means disposed opposite to the welding bead. Section leak detection device. 2. An enclosing case formed in a dish shape and having a flange surface around an opening, and a flange surface of the enclosing case is pressed against a back side of a welding bead of the member to be welded to thereby weld the member to be welded and the enclosing case. A case pressing means for forming a compartment between them, a gas filling means for filling a gas at a predetermined pressure in the compartment, a gas detecting means and a welding bead arranged respectively opposite to the welding bead. And a shape detecting means for detecting a shape of the weld. 3. The leak detecting device according to claim 2, wherein an annular groove is formed on the flange surface of the enclosing case along the flange surface, and the inside of the groove can be evacuated. 4. The leak detecting device according to claim 1, wherein the enclosing case is formed of a hard elastic member. 5. The gas detection means travels along a welding bead.
The welded portion according to claim 1, wherein the welded portion is formed.
Leak detection device. 6. A method for welding a gas detecting means and a shape detecting means.
A bead that runs along the bead
3. The leak detecting device for a weld according to claim 2. 7. The welded member is a three-phase split on-site transformer.
7. An inter-phase flange according to claim 1.
The leak detecting device for a welded part according to any one of the above.