JPH066235B2 - Automatic rail welding method - Google Patents

Description

The present invention relates to a rail automatic welding method.

(Prior Art) As a field welding method for rails, thermite welding and enclosed arc welding methods are widely used because they can be welded without applying pressure in the axial direction of the rail. However, the thermite welding method lacks quality stability in terms of weld performance, such as a high probability of breakage during use, and the enclosed arc welding method requires long welding time due to manual welding, depending on the skill of the welder. There were various problems such as doing. For this reason, fusion welding methods have been studied as an alternative to the current thermite welding and enclosed arc welding methods.

The techniques disclosed in Japanese Examined Patent Publication No. 59-21713, Japanese Unexamined Patent Publication No. 58-151980, and USP 4,413,169 (issued November 1, 1983) have also been proposed as alternatives to the current welding method for rails using the electroslag welding method. It is an automatic welding technology. However, these techniques are all methods of welding from the rail bottom to the head by electroslag welding with the multi-electrode consumable nozzle fixed at the initial position, and the non-consumable nozzle is used as in the present invention. It is different from the method that is performed by.

(Problems to be Solved by the Invention) All of the above techniques are fusion welding methods and do not require pressurization in the rail axis direction. Further, although some improvement in efficiency can be expected over the enclosed arc welding method, there are still some practical problems. I have left the problem.

That is, since all of the above welding methods are vertical electroslag welding methods for multiple electrodes using consumable nozzles, it is impossible to form a welded portion in a shape similar to that of a rail, There is no choice but to form an extra weld bulge on the abdomen. Therefore, in addition to consuming extra welding material, there is a drawback that the operability is extremely poor due to the complicated welding apparatus due to the large number of electrodes. or,
There is a drawback in that the welded joint performance is adversely affected because the overfilled shape formed including the abdomen is too large and it is difficult to control the shape of the weld toe.

(Means for Solving the Problem) The present invention has been made in view of the problems of the above-described technology, and uses a single non-consumable electrode and divides a metal equivalent to a portion forming a weld metal. By adopting the movable type, it is possible to form a welded portion that is made to approximate the shape of the rail by traversing the electrodes in accordance with the width shapes of the foot, abdomen and head of the rail. The summary is
In the automatic rail welding method using the electroslag welding method, flux is dispersed in the rectangular groove of the backing metal installed at the bottom of the rail foot, and the filler wire is electrically fed through the non-consumable nozzle. The non-consumable nozzle is repeatedly moved horizontally along the rectangular groove of the backing metal and raised to form the weld metal and the molten slag bath in the entire rectangular groove, and is continuously placed on the backing metal. In the rail foot frame that surrounds the rail foot, raise the non-consumable nozzle while repeatedly moving horizontally according to the width shape of the rail foot, and then slide on the rail foot frame. The abdomen inside the rail abdomen and head that abuts on the rail abdomen and head moves up the non-consumable nozzle in the abdomen, and the head again moves the non-consumable nozzle horizontally according to the rail head width. While raising or the above method In the automatic welding of rails, the wavy deformed filler wire is welded while rotating the filler wire around the feeding direction of the filler wire as a central axis or while swinging the tip of the filler wire in the rail axial direction. On the way.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the method of the present invention, and FIG. 2 is a side view of the embodiment seen from the end face direction of the rail which is the member to be welded.

In the figure, 1 and 2 are rails which are members to be welded,
The end faces are installed in a butted state with an appropriate groove interval. Reference numeral 3 is a backing metal having a groove 4 applied to the back surface of the rail foot portion, and is used for forming a waste metal portion for stabilizing the slag bath in performing electroslag welding.

5 and 6 are frame bodies placed on the upper surface of the rail foot portion, which are used as a pair before and after the rail and are placed so as to surround the groove of the rail foot portion. Used to prevent the outflow of metal. Numerals 7 and 8 are copper abdomen for rail abdominal head welding and are placed on the upper surfaces of the frames 5 and 6, and any driving means (not shown) such as a motor or a hydraulic drive mechanism accompanying the progress of welding. It is installed so that it can slide in the directions of arrows 9 and 10.

Reference numeral 11 is a filler wire, and 12 is a non-consumable nozzle that guides the filler wire 11 into the groove and supplies electric power from the welding power source to the filler wire 11.

The non-consumable nozzle 12 includes an oscillator 14 having a moving shaft that horizontally moves in the direction of arrow 13 and a carriage 16 that moves up and down in the direction of arrow 15.
It is held via a holder 17 and a connecting plate 18. Reference numeral 19 is a guide rail of the truck 16.

With the above configuration, the tip of the filler wire 11 is the locus in FIG.
Weld while drawing 20. The rail abdomen head welding and copper plates 7 and 8 are positioned at 7a and 8a at the time when welding is applied to the abdomen, that is, after point A on the locus 20.

The configuration in the embodiment of the method of the present invention has been described above.

Next, the method of the present invention will be described in more detail by following the welding procedure with reference to FIGS.

First, the welding state of the waste metal portion formed below the bottom surface of the rail foot portion will be described with reference to the schematic diagram shown in FIG.

In the figure, 21 is a molten type flux, 22 is a formed waste metal part, 23 is solidified slag covering the waste metal part 22, and 25 is a slag bath.

Welding is backing metal 3 applied to the back of the rail before welding begins.
In the molten flux 21 scattered in the groove 4 of the
It is performed by repeatedly moving the position 12 from a. At this time, the amount of the molten flux 21 that is preliminarily dispersed varies depending on the shape and size of the groove 4 of the backing metal 3 that is in contact with the back surface of the rail, but it does not hinder the melting of the molten flux 21 and is welded. Use an amount that does not expose the arc.

Further, when the melting start position is the non-consumable nozzle 12a, the welding progresses, and when it reaches the position of the non-consumable nozzle 12, the slag bath near the non-consumable nozzle 12a is the solidified slag 23. As the non-consumable nozzle 12 repeats and the non-consumable nozzle 12a approaches the non-consumable nozzle 12a, the solidified slag 23 is re-melted and becomes a slag bath 25. The range of
The entire surface of the groove 4 is filled with the slag bath 25, and a stable slag bath 25 for electroslag welding can be obtained.

In addition, the purpose of forming the discarded portion 22 is to use the slag bath described above.
In order to stabilize 25, the depth of the groove 4 needs to be 10 mm or more, and is preferably 40 mm or less from the viewpoint of welding efficiency. Also, the discard part 22 formed here
Will be removed as necessary when laying the rail joint on the track.

Next, the welding state of the rail foot portion will be described with reference to the schematic diagram shown in FIG.

The welding is continuously performed by the electroslag welding method without interrupting the welding in the slag bath 25 stabilized in the explanation of FIG.

In the schematic view shown in FIG. 4, the rail foot bead 24 extends over the rail foot surface, and the welding of the rail foot is almost completed.

In the figure, 24 is a bead at the bottom of the formed rail, 25 is a slag bath, and 7 and 8 are abdominal head / copper metal.

Further, the welding of the rail foot portion is progressed by the repeated movement of the non-consumable nozzle 12, but at this time, the horizontal stroke of the non-consumable nozzle 12 is reduced by repeating the welding according to the shape of the rail foot portion. In this case, since the surplus on the surface of the rail foot portion does not become large, the surplus shape as shown in FIG. 5 can be obtained, and the efficiency is good in the finishing process after welding.

Copper feet 7 and 8 have completed rail foot welding, and are non-consumable nozzles.
Positions 7a, 8a because 12 stops repetitive movement at the center of the rail and rail abdominal welding begins and contacts the rail
You have to move to (Fig. 2), so you must wait so that you can move quickly.

Next, welding of the abdomen and the head will be described with reference to the schematic diagram of FIG.

In the figure, 12b is the position of the non-consumable nozzle during abdominal welding, 26
Shows a slag bath during abdominal welding, 12c and 12d are movements of the non-consumable nozzle during head welding, and 27 is a slag bath during head welding.

For head welding, as shown in the figure, the non-consumable nozzle 12 has 12c and 12d.
Iterative movement is repeatedly performed between. Position 7a, 8a
Is in close contact with the rail, prevents slag 26, 27 and molten metal from flowing out during welding of the abdomen and head, and adjusts the bead shape to perform electroslag using a multi-electrode consumable nozzle. Unlike the welding method, it does not have a bead shape that largely protrudes from the rail shape, so it has an effect of obtaining a bead shape with high joint strength with high efficiency in the finishing process and less stress concentration when receiving bending load .

After the electroslag welding of the rail foot described with reference to FIG. 4, the repetitive movement of the non-consumable nozzle 12 is stopped at the center of the rail, and the non-consumable nozzle 12 is moved only upward to perform electroslag welding of the abdomen. . When the welding of the abdomen of the rail is completed and it is applied to the head, the non-consumable nozzle 12 restarts the repetitive movement according to the shape of the rail head, gradually increasing the stroke of the repetitive movement, and the width of the rail head is fully filled. Welding, that is, while repeatedly moving between the non-consumable nozzle positions 12c and 12d.

Also, when electroslag welding progresses from the rail abdomen to the head, the depth of the slag bath decreases, and slag scattering and arc exposure occur. Alternatively, the flux is replenished by a flux spraying device (not shown) to perform electroslag welding while compensating for the decrease in the depth of the slag bath 27.

Although the welding method of the present invention has been described above, in performing welding by the welding method of the present invention, until the filler wire tip reaches the point A of the locus 20 shown in FIG. 2 from the start of welding and the repetition of the non-consumable nozzle 12 stops. As for the slag bath 25 for electroslag welding, a wide range of slag can be quickly obtained by continuously spraying a small amount of the molten flux 23 in the vicinity of the non-consumable nozzle 12 by using a manual or flux spraying device (not shown). There is an effect of obtaining a more stable slag bath 25 by shifting to prevent slag scattering and arc exposure.

Further, in the welding method of the present invention, a non-consumable nozzle is used. However, if a welding nozzle is used in place of the non-consumable nozzle in the welding method of the present invention, the welding material increases by the amount of the consumable nozzle, and the nozzle length increases. It is not preferable because it is necessary to bring peripheral equipment such as a drying furnace to the welding site as much as is necessary.

Further, in the welding method of the present invention, since the automatic nozzle raising mechanism is used, it is easier to perform control such as resumption of neck swing by using a non-consumable nozzle.

Further, by using the non-consumable nozzle, it is possible to use a thin wire having a higher current density than that of the consumable nozzle, so that there is an effect that highly efficient electroslag welding can be performed.

FIG. 7 shows an example of a schematic diagram in which butt welding of rails is performed by the welding method of the present invention while rotating the tip of the filler wire about the filler wire feeding direction as the central axis.

In the figure, 28 is a plate fixing grooved ball bearings 29, 30 and 31 for deforming the filler wire 11 in a meandering manner.
The meandering wire 11 rotates as a result of the rotation.

Further, the rotation of the wire tip obtained by using the above-mentioned set of apparatus is performed at the same time as the start of the welding in the present welding method, so that the slag bath 25 is stirred in the welding of the backing metal 3 with the groove 4 for forming the waste metal portion. In the groove of the rail foot, abdomen, and head, the convection of the molten metal is more effective than the straight welding of the filler wire 11 for welding. It has the effect of eliminating defects such as blowholes and slag entrapment, and obtaining a rail joint with a better penetration shape.

In addition, even if the above-mentioned rail welding method is performed while swinging the tip of the filler wire in the rail axis direction, convection of the molten metal is often performed as in the case where the filler wire deformed into a corrugated shape is rotated. Is less likely to occur and sufficient penetration can be obtained.

(Example) An example will be described in which the rail 1321b rail for railroad welding is butt welded according to the configuration and procedure described above.

An example of the welding material and welding conditions of the embodiment according to the constitution of the present invention is shown below.

(1) Welding material and frame Welding wire: φ1.6 mm solid wire Flux: Melting type flux (SiO ₂ -CaO-T
iO ₂ system) Frame, etc .: Water-cooled copper plate on the back of the rail (with 30 ^t × 24 ^w × 220 ^L groove) Rail-foot water-cooled copper plate, Rail abdomen also used for water-cooled copper plate (2) Welding conditions Source: DC constant voltage power supply rating 500A Gap interval: 16mm Welding current: 400AmP Welding voltage: 40Volt Welding wire feeding: Welding wire transfer feeding ~ 40 times / minute Torch rising speed: ON by welding current detection ， OFFON → 15cm
/ Min Horizontal movement speed of torch: 15 cm / min As a result of welding in the above manner, the welding time in the example is about 15 minutes excluding setup and post-treatment, and high efficiency welding without defects can be performed. It was

(Effects of the Invention) According to the present invention, in the field welding of rails, there is no defect such as slag entrainment or fusion failure at low cost and high efficiency, and a rail welded joint in which the shape of the extra portion is appropriately controlled is provided. Obtaining automatic electroslag welding can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a side view of the same, FIG. 3 is a cross-sectional view during welding of a waste metal portion, and FIG. 4 is during welding of a rail foot portion. Sectional view, FIG. 5 is the same sectional view, FIG. 6 is a sectional view during welding of the rail abdomen and head, and FIG. 7 is a diagram showing welding during welding by the present invention while rotating the tip of the filler wire. A sectional view is shown. 1, 2 ... Rail 3 ... Back metal 4 ... Groove 5, 6 ... Rail Foot frame 7, 8 ... Abdominal head and copper copper alloy 9, 10 ... Abdominal head and copper metal sliding direction 11 … Filler wire 12… Non-consumable nozzle 13… Sliding direction of non-consumable nozzle 14… Oscillator 15… Cart lifting direction 16… Cart 17… Holder 18… Connecting plate 19… Guide rail 20… Filler wire tip locus 21… Melting Mold flux 22… Waste part 23… Solidified slag 24… Bead on rail foot 25,26,27… Slag bath 28… Plate 29,30,31… Grooved ball bearing 32… Motor 33… Plate rotation direction

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Nagato 5-10-1 Fuchinobe, Sagamihara-shi, Kanagawa Inside Nippon Steel Co., Ltd. 2nd Technical Research Institute (72) Inventor Hiroshi Kashihara 5-5, Fuchinobe, Sagamihara-shi, Kanagawa 10-1 Nippon Steel Co., Ltd. Second Technology Research Laboratory (72) Inventor Nobuyuki Aoki 5-10-1 Fuchinobe, Sagamihara-shi, Kanagawa Nippon Steel Co., Ltd. Second Technology Research Laboratory (72) Inventor Fujii Hirohisa 5-10-1 Fuchinobe, Sagamihara-shi, Kanagawa Nippon Steel Co., Ltd. 2nd Technical Research Institute (72) Inventor Yasuaki Otoguro 5-10-1, Fuchinobe, Sagamihara-shi, Kanagawa Nippon Steel Co., Ltd. 2nd (56) References JP-A 64-2779 (JP, A) JP-A 58-151980 (JP, A) JP 60-39165 (JP, Y2)

Claims (2)

[Claims] 1. A method of automatically welding a rail using an electroslag welding method, wherein flux 21 is sprinkled in a rectangular groove 4 of a backing metal 3 installed at the bottom of a rail foot, and filler wire 11 is not consumed. While supplying electricity through the nozzle 12, the non-consumable nozzle 12 is repeatedly moved horizontally along the rectangular groove 4 of the backing plate 3 and raised, so that the weld metal and the molten slag bath are distributed in the entire rectangular groove 4. Form and continue with the back metal 3
In the rail foot frames 5 and 6 placed on top of and surrounding the rail foot, the non-consumable nozzle 12 is repeatedly moved horizontally in accordance with the width shape of the rail foot, and then raised, and then continued. The non-consumable nozzle 12 is raised by the abdomen inside the abdomen head / copper metal plates 7, 8 that slide on the rail foot frames 5, 6 and contact the rail abdomen and head. Then, the non-consumable nozzle 12 is repeatedly moved horizontally according to the width of the head of the rail to raise the rail, and the rail is automatically welded. 2. The welding is performed while rotating the wavy deformed filler wire 11 around the feeding direction of the filler wire 11 as a central axis or while swinging the tip end of the filler wire 11 in the rail axial direction. The method for automatically welding a rail according to claim 1.