JPH0634876U - Oxidation protection device for welds of strip end welders - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a weld oxidation prevention device that has an excellent atmospheric shielding effect during welding and that can effectively eliminate spatter generated during welding by using the flow of an inert gas. . [Configuration] workpieces S _1, S inside the inert gas supply passage 3a of the _second clamping device 3, 4 for clamping the, 4a to form further aspect the inert gas supply passage 3a of the clamping device 3, 4, Jet holes 3b and 4b are formed which communicate with 4a and jet an inert gas to the welded portion. by this,
The inert gas is surely supplied to the weld, and the spout of the gas effectively eliminates spatter during welding.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a weld oxidation preventing device for a strip end welder such as a flash pad welder and a laser beam welder.

[0002]

[Prior art]

 In various types of welding such as flash butt welding and laser beam welding, high quality welding is possible by preventing oxidation of the welded portion, and therefore various measures have been taken conventionally.

In Japanese Unexamined Patent Publication (Kokai) No. 49-9647, the vicinity of the weld is surrounded by a gas containing a reducing gas such as ethane, propane, butane, butylene and the gas is burned and heated to burn the weld to the atmosphere. It is disclosed that the oxygen is blocked from oxygen, and in JP-A-59-118282, a substance such as a carbon polymer or an organic compound that generates a gas other than oxygen by combustion is attached to the lower surface of the member to be welded. It is disclosed that welding is carried out later and the atmosphere is shielded by the combustion gas of this substance. Further, JP-A-60-115679 discloses that oil is applied to the welded portion and burned at the time of welding. Atmospheric shielding is disclosed.

In any of these methods, it is necessary to burn at a good timing at the time of welding, but since the heat at the time of welding is used to ignite, the timing of the atmospheric shield due to combustion starts the welding. It tends to be slightly behind the timing, and it is difficult to completely shield the entire weld with the combustion gas during the welding time.

On the other hand, in Japanese Patent Laid-Open No. 56-50789, it is assumed that a chamber that seals a welded portion is formed and that an inert gas is supplied into the chamber so that welding is not performed by using the combustion gas. Welding equipment is disclosed that is capable of gas sealing the entire section.

According to this apparatus, since the oxidation of the welded portion can be prevented by the inert gas, it is not necessary to burn the reducing gas or the like with the welding in a timely manner as in the above method, and the welding can be started. From time to time, it is possible to reliably seal and create a non-oxidizing atmosphere.

[0007]

[Problems to be solved by the device]

 However, the chamber of the apparatus disclosed in Japanese Patent Laid-Open No. 56-50789 has a wide range including the welded portion, and therefore a large amount of inert gas is required, and the efficiency at the essential welding point is high. Inert gas cannot be supplied well. Further, such an inert gas is supplied for the purpose of creating a non-oxidizing atmosphere in the chamber, and the flow of the inert gas supplied is small, so that the spatter generated in the weld cannot be effectively discharged and removed.

The problem to be solved by the present invention is a strip end face welding machine having an excellent atmospheric shielding effect during welding and capable of effectively eliminating spatter generated during welding by utilizing the flow of an inert gas. To obtain a welded part antioxidant device.

[0009]

[Means for Solving the Problems]

 In order to solve the above problems, the welding end oxidation preventing device of the strip end face welding machine of the present invention forms an inert gas supply path inside the clamp device for clamping the material to be welded, and further, on the side surface of the clamp device. It is characterized in that a jet port communicating with the inert gas supply path and jetting an inert gas is formed in the welded portion.

The jet outlet may be capable of supplying an inert gas to the entire length of the welded portion, and may have a slit shape elongated in the welding direction or a plurality of nozzle shapes.

[0011]

[Action]

 In the present invention, since the means for supplying the inert gas to the clamp device for clamping the material to be welded, which is located in the shortest distance from the welding part, is provided, the inert gas is reliably supplied to the welding part and the gas jet This effectively eliminates spatter during welding.

[0012]

【Example】

 The following is an example of applying the welded portion oxidation preventing apparatus, which is an embodiment of the present invention, to a flash butt welding machine.

FIG. 1 is an overall schematic view of a flash butt welding machine, FIG. 2 is a cross-sectional view of a clamp device that constitutes the weld oxidation preventing device of the present invention, and FIG. 3 is a plan view of FIG.

In FIG. 1, reference numeral 1 is a fixed stand on the outgoing side, 2 is a moving stand on the incoming side, and the outgoing fixed table 1 is provided with upper and lower electrodes / clamps 3 for clamping the preceding plate S _1. The movable table 2 is provided with upper and lower electrode / clamps 4 for clamping the trailing plate S ₂ . Reference numeral 5 denotes a hood composed of casings 5a and 5b attached to the fixed base 1 and the movable base 3, respectively, and the casings 5a and 5b are integrated during welding so that the interior of the hood 5 becomes airtight. Reference numeral 6 is an exhaust duct attached to the casing 5b.

With reference to FIGS. 2 and 3, the electrode / clamp 3 and the electrode / clamp 4 composed of upper and lower members are provided with inert gas supply paths 3a and 4a in the longitudinal direction, and the side surface, that is, the welding. On the part side, jet ports 3b, 4b for supplying an inert gas to the entire surface of the welded part are provided. The orifices 3b and 4b are formed with orifices having a smaller resistance to gas flow toward the downstream side, and the inert gas is uniformly ejected over the entire welded portion. The inert gas supply paths 3a and 4a of the clamp are connected to an inert gas supply device (not shown) by flexible hoses 3c and 4c. In the above embodiment, the inert gas supply paths 3a and 4a and the jet ports 3b and 4b are provided on the upper and lower members of the electrode / clamp 3 and the electrode / clamp 4, respectively. The inert gas supply passage and the jet outlet along the side surface may be used. In the operation of the flash butt welding machine having the above-described structure, the leading plate S ₁ and the trailing plate S ₂ are clamped from above and below by the electrodes and clamps 3 and 4, respectively, and the moving table 2 is moved forward to move the trailing plate S ₂ into position. It moves in the direction of the leading plate S ₁ . At this time, the inert gas supply device (not shown) operates in conjunction with each other, and the injection pressure of 0.5 from the inert gas ejection ports 3b and 4b of the clamps 3 and 4 constituting the welding part oxidation preventing device to the welding part. ~ 3. 0 kg / cm ² of inert gas is supplied. In this way, the inert gas is ejected from the shortest distance from the welded portion, and the welded portion can be reliably purged with gas. In this state, the movable table 2 is further advanced to perform flushing and upsetting, and butt welding of the trailing plate S ₂ and the preceding plate S ₁ is performed. Further, the switch of the exhaust duct 6 is turned on at the same time when the flash occurs, and the exhaust gas including the spatter generated during the flash is efficiently removed to the outside by the jet flow of the gas. The supply of inert gas is automatically stopped when the welding is completed.

Using the above equipment, hot-rolled steel sheets of high-strength 780N class high-strength steel were flash-butt welded, and as a comparative example, welding was performed under the same conditions except that the inert gas shield was not used. The Erichsen test was carried out.

As a result, in the case of welding using the above apparatus, the pass rate was almost 100%, whereas in the case of welding in the atmosphere, the pass rate was 0%.

[0018]

[Effect of device]

 The present invention has the following effects.

(1) The inert gas is surely supplied to the welded portion, and the gas sealing effect is improved.

(2) Since the clamp itself is provided with means for supplying an inert gas, another device such as a jet nozzle is not required, and the device can be simplified.

(3) By performing the inert gas purge welding while operating the flue gas blower, it is possible to prevent flaws on the surface of the metal plate due to the welding sputter.

(4) By changing the inert gas supply distribution in the welding line direction, it is possible to obtain a uniform residual oxygen concentration over the entire welding line.

[Brief description of drawings]

FIG. 1 is a schematic front view of a flash butt welding machine.

FIG. 2 is a front sectional view of the clamp device shown in FIG.

3 is a plan view of the clamp device shown in FIG. 1. FIG.

[Explanation of symbols]

1 fixed base 2 movable base 3, 4 electrode / clamp 3a, 4a gas supply path 3b, 4b gas outlet 5 hood 5a, 5b casing 6 exhaust duct S ₁ leading plate S ₂ trailing plate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B23K 37/04 D 7011-4E

Claims (1)

[Scope of utility model registration request] 1. An inert gas supply passage is formed inside a clamp device for clamping a material to be welded, and the inert gas supply passage is connected to a side surface of the clamp device and an inert gas is ejected to a welded portion. Oxidation prevention device for welded part of strip end face welder with jet outlet formed.