JPH11267830A - On the spot welding method of hydraulic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a welding man-hour and shorten a welding period as well while maintaining welding quality. SOLUTION: This on-the-spot welding method of a hydraulic equipment carries out a MAG welding by attaching a back up plate 6 to a rear side of a groove while holding a groove gap G at a given interval after the divided pieces 1, 1 of the hydraulic equipment are made to face together. In that case, as the back up plate 6 is mounted with an aluminum tape 7, a groove irregularity D is required to be adjusted at 0-2 mm. At a portion corresponding to the V groove rear side of the back up plate 6, a weld overlay is formed by the welding, and a spherical shaped concave part 6 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-site welding method for hydraulic equipment applied to a case where split pieces of a suction pipe liner and a spiral casing of a water turbine and a pump turbine are welded on site.

[0002]

2. Description of the Related Art Conventionally, the suction pipe liners of a water turbine and a pump turbine which are hydraulic equipment are welded in the order shown in FIGS. 7 (A) to 7 (D) and FIG. That is, first, after the split pieces 1 and 1 of the suction pipe liner are fitted to each other, the groove gap is controlled to 3 ± 3 mm, and the coated arc is welded by the coated arc welding machine 2 which is manual welding as shown in FIG. Perform welding. Next, at the time of this covering arc welding, a welding start portion (first
Since a defect easily occurs in the layer portion, back digging is performed on the back side of the groove by carbon gouging 3 as shown in FIG.

[0003] After that, the surface dug out by the carbon gouging 3 is polished by a grinder 4 as shown in FIG. 7 (C), and as shown in FIG.
T: Penetration Test) is performed to confirm that back digging was performed up to a portion having no defect. Further, as shown in FIG. 7 (D), the back digging side was welded by the covered arc welding machine 2 to maintain the welding quality.

[0004]

However, in order to install the suction pipe liner on site by the above-described conventional welding method, defects are likely to occur in the welding start portion (first layer portion), so that the welding quality is maintained. Therefore, back digging must be performed on the back side of the groove by the carbon gouging 3 and the back digging side must be welded, so that the welding period is a critical step. In particular, when the number of divisions of the suction pipe liner is large, there is a problem that the welding line becomes long and the welding amount increases, and the welding period occupies about half of the installation period.

The present invention has been made in view of the above circumstances, and has as its object to provide a method for on-site welding of hydraulic equipment in which welding time is shortened and welding man-hours are reduced while maintaining welding quality. And

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that after splitting a split piece of a hydraulic device, the groove gap is maintained at a predetermined interval,
MAG welding is performed by attaching a backing plate to the back side of the groove.

According to the first aspect of the present invention, by attaching the backing plate to the back side of the groove during MAG welding, the welding start portion is received by the backing plate, so that defects are less likely to occur in the welding start portion, and carbon Gouging eliminates back digging on the back side of the groove or welding the back digging side.

According to a second aspect of the present invention, the hydraulic equipment according to the first aspect is a suction pipe liner for a water wheel and a pump water wheel.

According to a third aspect of the present invention, the hydraulic equipment according to the first aspect is a spiral casing of a water turbine and a pump turbine.

According to a fourth aspect of the present invention, the groove gap according to the first aspect is set to 4 ± 2 mm.

According to the fourth aspect of the present invention, the groove gap is set to 4 ± 2 mm, so that the groove can be formed with a margin and the strength to withstand water pressure can be obtained. Here, if the groove gap is more than 6 mm or less than 2 mm, no excess is formed, and strength to withstand water pressure cannot be obtained.

A fifth aspect of the present invention is characterized in that the backing plate according to the first aspect is made of a ceramic material.

According to the fifth aspect of the invention, since the backing plate is made of a ceramic material, it can sufficiently withstand the welding temperature of MAG welding.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of a field welding method for hydraulic equipment according to the present invention, FIG. 2 is an explanatory view showing dimensional control of the field welding method of the embodiment, and FIG. It is explanatory drawing which shows the assembling order of the draft pipe liner which applies a field welding method.

The parts to be welded in the present embodiment are a suction pipe liner of a water turbine and a pump water turbine as hydraulic equipment, and this suction pipe liner lines a part of the suction pipe to protect concrete. It is a metal liner.

As shown in FIG. 3, all of the divided pieces of the suction pipe liner 5 are assembled in accordance with the order of circled numbers (fitting).
After that, as shown in FIG.
Is set to 4 ± 2 mm.

Further, a backing plate 6 made of a ceramic material is provided on the back side of the V groove with aluminum (A) having a heat-resistant adhesive.
L) Attach with tape 7. Here, since the backing plate 6 is attached with the aluminum tape 7, it is necessary to adjust the groove difference D to 0 to 2 mm. In a portion corresponding to the back side of the V groove of the backing plate 6, a spherical concave portion 6a is formed in order to form a margin by welding.

Next, the above-mentioned assembly control is performed, and as shown in FIG. 1, the gaps of the divided pieces 1 and 1 are MAG-welded by a MAG welding machine 8 which is a semi-automatic welding, and as shown in FIG. ３3 mm.

In order to keep the groove gap G at 4 ± 2 mm or to keep the groove gap D at 0 to 2 mm, a groove alignment jig shown in FIGS. 4A to 4C is used. use.

That is, in order to keep the groove gap G at 4 ± 2 mm, for example, as shown in FIG. 4 (A), the groove alignment plates 9, 9 are fixed to the back side of the groove of the divided pieces 1, 1. A plurality of insertion holes 9a formed in the groove alignment plates 9, 9 are inserted through taper pins (not shown) to fit the grooves of the divided pieces 1, 1 and tightened with bolts to measure the size of the groove gap G. To adjust.

In order to adjust the groove difference D to 0 to 2 mm, as shown in FIG. 4B, a horse 10 is fixed to the back side of one of the divided pieces 1, and the horse 10 and the other horse 10 are fixed. Split piece 1
When the arrow 11 is hammered in the direction of arrow a with a hammer or the like between the back side of the other and the other divided piece 1 is lowered in the direction of arrow b,
The groove difference D is adjusted.

Further, in order to adjust both the groove gap G and the groove difference D, as shown in FIG. Dog 1
2 and the U-shaped dog 12 is provided with
The frame plate 13 in which a is integrally formed is arranged. And U
When the arrow 11 is struck between the dog-shaped dog 12 and the frame plate 13, it is possible to adjust the difference in the groove. When the arrow 11 is struck between the U-shaped dog 12 and the projection 13a of the frame plate 13, the dimension of the groove gap G can be adjusted.

On the other hand, when performing MAG welding by the MAG welding machine 8, as shown in FIG.
A spacer 14 having a thickness of about 1 mm is provided, and is temporarily attached to the groove of the divided pieces 1 and 1 at an interval of about 30 cm by about 3 to 5 mm. Then, the spacer 14 is removed, and then MAG welding is performed. Accordingly, MAG welding can be performed while preventing weld clogging and maintaining the groove gap G at the set value. Here, if the spacer 14 is not provided, the gap between the divided pieces 1 and 1 contracts during MAG welding, and the groove gap G cannot be maintained at the set value.

If the groove gap G cannot be maintained at 4 ± 2 mm even when the groove adjusting jig shown in FIGS. 4A to 4C is used, grinder finishing is performed or extra welding is performed. And adjust it.

Next, the operation and effect of this embodiment will be described.

After fitting the split pieces 1 and 1 of the hydraulic equipment,
While holding the groove gap G at a predetermined interval, the backing plate 6 is attached to the back side of the groove with an aluminum tape 7 and MAG-welded by a MAG welding machine 8, so that the welding start portion is formed by the backing plate 6. As a result, defects are less likely to occur in the welding start portion, and it is not necessary to perform back digging on the back side of the groove by carbon gouging or weld the back digging side.

By using the ceramic material for the backing plate 6, it is possible to sufficiently withstand the welding temperature of MAG welding.

The groove gap G of the divided pieces 1 and 1 is set to 4
By setting it to ± 2 mm, a margin can be formed at the groove, and a strength that can withstand water pressure can be obtained.

FIG. 6 is a schematic plan view showing a spiral casing to which one embodiment of the on-site welding method for hydraulic equipment according to the present invention is applied.

As shown in FIG. 6, a split piece 1 of a spiral casing 15 of a water turbine and a pump water turbine as hydraulic equipment.
The same effect can be obtained by welding by the same welding method as in the above embodiment after the entire number of 6 has been fitted.

Therefore, the present invention can be applied to the spiral casings of water turbines and pump turbines as hydraulic equipment, and can provide a highly versatile welding method.

[0033]

As described above, according to the present invention,
After fitting the split pieces of the hydraulic equipment, the backing plate is attached to the back side of the groove and MAG welding is performed while maintaining the groove gap at a predetermined interval, so that the back side of the groove is formed by carbon gouging. No digging or welding of the back digging side is required, stabilizing the welding quality, shortening the on-site welding period and reducing man-hours.

Further, since the groove gap is set to 4 ± 2 mm, a margin can be formed in the groove, and the strength to withstand water pressure can be obtained.

Further, since the backing plate is made of a ceramic material, it can sufficiently withstand the welding temperature of MAG welding.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a field welding method for hydraulic equipment according to the present invention.

FIG. 2 is an explanatory view showing dimensional management of the on-site welding method of the embodiment.

FIG. 3 is an explanatory view showing an assembling order of a draft pipe liner to which the on-site welding method of the embodiment is applied.

FIGS. 4A, 4B, and 4C are perspective views showing a groove alignment jig used in the embodiment.

FIG. 5 is an exemplary perspective view showing a spacer used in the embodiment;

FIG. 6 is a schematic plan view showing a spiral casing to which the on-site welding method of the embodiment is applied.

FIGS. 7A, 7B, 7C, and 7D are explanatory views showing a welding sequence of a suction pipe liner by a conventional welding method.

FIG. 8 is a process chart showing a welding order of a suction pipe liner by a conventional welding method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 split piece 5 suction pipe liner 6 backing plate 6a recess 7 aluminum tape 8 MAG welding machine 9 groove alignment plate 9a insertion hole 10 horse 11 arrow 12 U-shaped dog 13 frame plate 13a convex portion 14 spacer 15 spiral casing 16 split Piece D Mismatch of groove G Groove gap

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B23K 37/06 B23K 37/06 F

Claims (5)

[Claims] 1. A hydraulic device characterized in that, after fitting a split piece of a hydraulic device, a backing plate is attached to the back side of the groove and MAG welding is performed while maintaining the groove gap at a predetermined interval. Local welding method. 2. The method according to claim 1, wherein the hydraulic equipment is a suction pipe liner of a water turbine and a pump water turbine. 3. The method according to claim 1, wherein the hydraulic equipment is a spiral casing of a water turbine and a pump turbine. 4. The method according to claim 1, wherein the groove gap is set to 4 ± 2 mm. 5. The method according to claim 1, wherein the backing plate is made of a ceramic material.