JP2004202521A - Welding method and welding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a welding method capable of easily and reliably performing beautiful fine welding while hardly forming oxides on a metal member, and to provide welding equipment therefor. <P>SOLUTION: A metal member 3 is preliminarily heated by running the current in the metal member 3 to be repaired for a short time. A welding material 2 with at least a part thereof melted is spotted and tack-welded to the preliminarily heated metal member 3. In addition, the welding material 2 tack-welded to the metal member 3 is completely melted by arc discharge to perform permanent welding of a part to be repaired of the metal member 3. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding method and a welding apparatus suitable for repairing fine defects.
[0002]
2. Description of the Related Art Conventionally, when defects such as scratches and cracks occur in metal members such as molding dies, press dies, and jigs, the metal members having the defects are removed on site and transported to a factory. In order to minimize the interruption of on-site work and improve work efficiency, it is required to perform on-site welding repair work for small defects. ing.
[0003] Conventionally, when daily necessities such as golf clubs or jewelry made of precious metals have defects such as minute scratches or cracks, they have been repaired or repaired by brazing or the like. There is a need for a means that can perform beautiful repair more easily and reliably.
[0004] In view of such a recent demand, the inventors of the present invention have stated, "A suitable amount of fine powdered welding powder is placed on a repaired portion of a metal member or a thin plate-shaped welding material is applied to the welded portion of a welding machine. The primary electrode is locally pressed against the welding powder or the welding material, and a large current of 300 to 1500 A is supplied in a pulse form within a short time of 1/1000 to 4/1000 seconds to form a point-like welding metal on the metal member. Forming, welding or welding a point-like or line-like or plane-like overlay of a necessary thickness in a necessary range of the repaired portion by continuously or overlapping a large number of the deposited metals, as described above. A step of placing the overlay weld formed at the repair location of the metal member in an inert gas atmosphere, bringing the primary electrode of the arc melting machine close to the overlay weld and radiating an arc for a short time to remelt the deposited metal. And the above-mentioned Part deletes the excess material after solidification, characterized in that finish by polishing the stain has proposed a weld repair process. "Metal member (Patent Document 1).
[0005] However, in this welding method, an arc discharge is performed on a metal member or a welding material at room temperature, so that a relatively high current is applied for a long time to completely melt the welding material. It was necessary to apply and emit an arc. For this reason, in this welding method, there is a problem that oxides are generated due to the influence of high heat in the vicinity of the repaired portion of the metal member, and the welding range of the welding material is easily increased. However, since a more beautiful welding method was required, a solution was desired.
[0006]
[Patent Document 1]
JP-A-7-57449 [0007]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has a welding method capable of repairing a fine defective portion with a beautiful finish while suppressing an adverse effect due to heat during welding. , And a welding device.
[0008]
Means for Solving the Problems The inventor of the present invention has conducted intensive studies to solve the above-mentioned problems. As a result, the metal member to be repaired and the welding material are heated in advance, and then the welding material is temporarily attached and the arc is removed. As a result of performing the main welding by electric discharge, it was found that desired tacking and main welding could be performed under conditions in which the amount of current and the conduction time were significantly reduced as compared with the conventional method, and the present invention was completed.
That is, according to the present invention, the metal member to be repaired is heated for a short time by pre-heating the metal member, and the preheated metal member is spotted with a welding material at least partially melted. The present invention provides a welding method characterized in that the welding material temporarily attached to the metal member is completely melted by arc discharge and the repaired portion of the metal member is fully welded.
In the present invention, a primary electrode and a normal secondary electrode in which a welding material is detachably attached to the electrode main body and whose tip projects are inserted, and an ordinary secondary electrode are electrically connected to a metal member. It is preferable that preheating is performed, then the primary electrode is separated from the metal member to generate an arc, the tip of the welding material is melted, and the tip of the melted welding material is pressed against the metal member for temporary attachment.
In the present invention, the preheating is preferably performed by applying a current of 0.1 to 1000 A in a pulse form for 0.1 to 5.0 seconds. It is also preferable to raise the temperature to 20 to 1000 ° C.
In the present invention, for example, the metal member includes any one of mold steel, cast steel, aluminum, copper, magnesium, gold, silver, and platinum, or at least one of these metals. It can be applied to alloys, oxides, carbides, nitrides, and the like, and among them, metal members are made of aluminum, copper, zinc, or alloys or oxides of these materials. It can be preferably applied to large ones.
Further, the welding material is preferably made of the same material as the metal member or a metal material which is easily fused. For example, the welding material may be steel for mold, cast steel, aluminum, copper, magnesium, gold, silver, Platinum, zinc, or an alloy, oxide, carbide, or nitride containing at least one of these metals is preferable.
In the main welding by arc discharge, the electrode is brought close to the metal member at a position of 0.1 to 0.5 mm and a current of 0.1 to 1000 A is pulsed for 0.001 to 1.0 second. It is preferable to conduct the current by applying a current.
Further, the present invention provides a welding apparatus suitable for such a welding method, in which a welding material is detachably fitted into an electrode body with its tip protruding, and is electrically connected to a primary electrode and a metal member. A preheating / temporary attachment portion having a secondary electrode that is electrically connected, a power supply for supplying a current of 0.1 to 1000 A in a pulse form for 0.1 to 5.0 seconds between the electrodes, and a metal member. There are a primary electrode that is brought into proximity, a secondary electrode that is electrically connected to the metal member, and a power source that applies a current of 0.1 to 1000 A in a pulse between the pair of electrodes for 0.001 to 1.0 seconds. The present invention also provides a welding device comprising: a main weld portion for completely melting a welding material temporarily attached by arc discharge and welding a repaired portion of a metal member.
[0016]
Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a process diagram schematically showing one embodiment of the welding method of the present invention.
As shown in FIG. 1, in the welding method of the present invention, the metal member 3 to be repaired is first pre-heated by short-time energization. As a result, the current and the welding time during the main welding, which will be described later, can be effectively reduced, and the formation of oxides can be prevented.
In the present invention, the preheating is preferably performed by raising the temperature of the metal member 3 and further the welding material 2 to 10 to 1500 ° C., and more preferably to 20 to 1000 ° C. .
If the temperature of the metal member 3 and further the welding material 2 is raised to this temperature range, the current and welding time in spot welding, which will be described later, can be effectively reduced, and oxidation is also performed in preheating. There is no problem of forming an object.
In the present invention, the current applied during the preheating raises the temperature of the metal member 3 (and the welding material 2) to the desired temperature in a short time, thereby avoiding the problem of oxide formation. The range is preferably, specifically, a current of 0.1 to 1000 A is preferably applied, a current of 1.0 to 800 A is more preferably applied, and a current of 5.0 to 700 A is applied. Particularly preferred.
From the same viewpoint, the current application time is preferably 0.1 to 5.0 seconds, more preferably 0.2 to 4.5 seconds, and particularly preferably 0.3 to 4.0 seconds. preferable.
Further, it is preferable to select a suitable range of the current to be supplied and the current supply time in accordance with the material of the metal member to be supplied, and for example, aluminum, copper, zinc, or an alloy or oxide thereof. In the case of a material having a large thermal diffusivity, a current of 10.0 to 1000 A is preferably applied by passing a current for 0.5 to 5.0 seconds, and a current of 20.0 to 900 A is applied to a current of 1.0 to 1.0 A. It is more preferable to carry out the current supply for 4.5 seconds.
As shown in FIG. 1, in the welding method according to the present invention, a welding material 2 at least partially melted is spotted and temporarily attached to a metal member 3.
In the present invention, as a method of temporarily attaching the welding material 2 to the metal member 3, for example, (1) a part of the welding material is melted by utilizing frictional heat between the welding material and the metal member, (2) A welding material is disposed on a metal member in advance, a current is applied to the metal member and the welding material, and the welding material is melted by resistance heat, and the metal is welded. A method of welding to the member (not shown), or (3) as shown in FIG. 1, the welding material 2 is detachably fitted to the primary electrode 11 in a state where the welding material 2 can be brought into contact with the metal member at the tip thereof. A method of melting the tip 2a of the welding material 2 by causing the electrode 4 in which the welding material 2 is fitted to emit an arc in the vicinity of the metal member 3 and pressing the melted tip 2a to the metal member is exemplified. it can.
Among them, various types of welding materials such as a powder-like material and a rod-like material can be used, and it is easy to temporarily attach a necessary amount of welding material in a required range. A heat tacking method is preferred. Further, since the welding material 2 can be pressed against the metal member 3 and spotted on the metal member 3, even if the material of the metal member 3 is alumina or the like having high thermal conductivity, it can be easily temporarily attached, and From the point that the fine welding material 2 to the relatively large welding material 2 can be easily and reliably pin-pointed at the pinpoint, the temporary bonding method using an arc is preferable.
In the case where the temporary bonding is performed by the above-mentioned arc, the preheating step and the temporary bonding step can be performed continuously, and the workability is extremely high. Therefore, as shown in FIG. The welding material 2 is detachably inserted into the electrode main body of the metal member 4 in a state where the welding material 2 can be detached and the tip thereof can be brought into contact with the metal member, and the primary heating and the secondary electrode 5 are preheated by the metal member. 3, the tip of the welding material 2 was melted by continuously separating the primary electrode 4 (welding material 2) from the metal member 3 and generating an arc. It is preferable that the welding material 2 is pressed against the metal member 3 to perform the temporary attachment.
In the present invention, it is preferable to clean the vicinity of the repaired portion 10 of the metal member 3 with acetone or the like in advance before removing the welding material 2 in order to remove oil and dust. .
The welding material 2 used in the present invention is preferably made of the same material or an easily fusible metal material with a metal member 3 to be described later in order to strengthen the repaired portion after welding. For example, it consists of any one of mold steel, cast steel, aluminum, copper, magnesium, gold, silver, platinum, or zinc, or an alloy, oxide, carbide, or nitride containing at least one of these metals. Things can be mentioned.
The welding material 2 may be appropriately selected depending on the size and shape of the repaired portion 10 of the metal member 3 to be welded. For example, a powder-shaped material, a wire-shaped material, or a rod-shaped material can be used. And the like. In addition, when applying the linear welding material 2 to fine welding, it is preferable that a diameter is 0.1-5.0 mm.
Further, in the tacking method using an arc shown in FIG. 1, the amount of generated heat is suppressed to reduce the influence of heat on the metal member 3 such as formation of an oxide, and to facilitate continuous operation. For this reason, it is preferable to perform the temporary attachment under the same conditions as the energizing current and energizing time described in the preheating.
In the present invention, in the method of tacking by means of an arc, the arc 1 is discharged by bringing the electrode 11 made of the welding material 2 close to the metal member 3 to be repaired by about 0.3 to 0.7 mm. Is preferred.
The welding material 6 may be of an appropriate size in accordance with the size of the repaired portion 10 of the metal member 3 to be welded. In the case of welding, it is preferable to use one having a length of 0.1 to 5.0 mm so that welding can be performed by short-time energization at the time of main welding to be described later.
In the tacking method utilizing resistance heat, the secondary electrode is brought into contact with a metal member, and at the same time, the primary electrode is pressed against a powdery or rod-like welding material, and the above-described pulse current is applied to perform welding. The material may be welded to the metal member.
At this time, it is preferable that the primary electrode has a shape such as a tapered shape that can locally press the welding material. When a powder-like welding material is used, it is also preferable to use a primary electrode having a magnetic force such as a magnet built-in (not shown).
As shown in FIG. 1, in the welding method of the present invention, the welding material 6 temporarily attached to the metal member 3 is melted by the arc discharge 1 and the repaired portion of the metal member 3 is finally welded. .
As a result, the welding material 2 is melted in a state where the electrode 11 and the welding material 2 are separated from each other, so that the welding material 2 does not adhere to the electrode 11, and the pin 11 does not depend on the material of the metal member 3. Can be welded at points. Further, since the temporarily attached welding material 6 can be instantaneously and completely melted by the arc discharge 8, the welding metal 13 which is 100% alloyed without forming an oxide is brought into close contact with the metal member and welded. Repair without metal peeling can be performed.
In the welding method according to the present invention, in order to suppress the deterioration of the welding material 6 and the metal member 3, an inert gas such as an argon gas or a helium gas, or a protective gas 7 composed of a carbon dioxide gas or the like is used in an amount of 2 liters. It is preferable to perform arc discharge while discharging to the welding material 2 on the metal member 3 at a flow rate of / min or more.
The primary electrode 11 used in the main welding is preferably one that does not melt by arc discharge, and is preferably made of, for example, tungsten or a tungsten alloy.
In the main welding according to the present invention, the primary electrode is set at 0.1 to 0.1 mm with respect to the metal member 3 so that the welding material 2 is completely melted but an oxide or the like is not formed on the metal member 3. It is preferable to conduct the current by passing a current of 0.1 to 1000 A in close proximity to the position of 5 mm, more preferably to a current of 20.0 to 900 A, and particularly preferably to a current of 100 to 900 A.
The main welding in the present invention is performed in a pulsed manner for 0.001 to 1.0 seconds in order to suppress the overall heat generation and to reduce the influence of heat on the metal member 3 such as formation of oxide. It is preferable to carry out the process by applying a current, more preferably to perform the process in a pulsed manner for 0.01 to 0.5 seconds, and particularly preferably to perform the process in a pulsed manner for 0.03 to 0.3 seconds.
In the present invention, since the metal member 3 and the welding material 2 are pre-heated in advance, the desired main welding can be performed with a lower current and a shorter pulse discharge than the conventional method. It has become.
In the present invention, the repair may be completed in the above steps, but it is preferable to polish the vicinity of the repaired portion in order to remove excessively deposited metal.
Next, a welding apparatus suitable for such a welding method will be described.
As a welding apparatus suitable for the welding method of the present invention, a preheating / heating method in which a current is applied to a metal member to generate resistance heat to the metal member, and a part of the welding material is melted and welded to the preheated metal member. What has a temporary attachment part (meaning "the part involved in preheating and temporary attachment"; the same shall apply hereinafter) and a main welding part that completely melts the temporarily attached welding material. Can be.
In the preheating / temporary attachment portion according to the present invention, the welding material is electrically connected to the primary electrode and the metal member which are detachably fitted to the electrode body with its tip protruding. It is preferable to have a secondary electrode and a power supply for supplying a current of 0.1 to 1000 A between these electrodes in a pulsed manner for 0.1 to 5.0 seconds.
Further, as the main welding portion, a primary electrode which is close to the metal member, a secondary electrode which is electrically connected to the metal member, and a current of 0.1 to 1000 A is applied between the pair of electrodes. It is preferable to use a power supply having a pulsed power supply for 001 to 1.0 seconds.
As a power source of the preheating / temporary attaching section, for example, a power supply having an AC / DC converter 31, a discharge time control section 33, and a current control section 32 as shown in FIG. it can. Further, as a power supply used for the welding device, a power supply including a power unit 34, a discharge time control unit 33, and a current control unit 32 as shown in FIG. be able to.
Further, in the main welding portion by arc discharge, in addition to an electrode which is electrically connected to the power supply 22 to discharge the arc, a gas discharging means which communicates with a gas source and discharges a protective gas toward a repair portion is provided. Are preferred.
In the welding apparatus of the present invention, it is preferable that each power supply of the preheating / temporary attachment section and the main welding section can be switched by a switch. Are preferably replaceable by removal.
In the welding apparatus of the present invention, even if a gas source is provided in the apparatus, a protective gas is introduced from an external gas source (not shown) through a protective gas inlet (not shown). The gas source may not be provided in the apparatus.
The other conditions, such as the setting conditions of each part of the welding apparatus, are the same as those described in the above-described welding method of the present invention, and a description thereof will be omitted.
[0050]
EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to the following examples.
[0051]
(Example 1)
First, after cleaning the surface of a metal member made of alumina having a part of cracks with warm water, a primary electrode in which a wire made of aluminum having a diameter of 0.5 mm and a length of 3.0 mm is inserted and a normal secondary electrode are inserted. The next electrode was brought into contact with the metal member at positions on both sides of the cracked portion, and a current of 100 A was applied in a pulsed manner for 0.3 seconds to heat the metal member to 200 ° C.
Next, the primary electrode was separated from the metal member by about 0.5 mm to generate an arc. Immediately thereafter, a welding material whose tip was melted by the arc was spotted and temporarily attached to the metal member.
Next, the power source was switched to a power source for the main welding, the primary electrode was replaced with a tungsten arc discharge electrode, and the electrode was positioned at about 0.5 mm from the metal member, and a current of 150 A was pulsed for 1.0 second. The main welding was carried out by applying an electric current to the welding member and discharging an arc toward the welding material spotted on the metal member. The main welding was performed while flowing argon gas.
When the periphery of the welded portion after completion of the repair was confirmed with a magnifying glass, no oxide was formed and a beautiful finish was confirmed. Further, when the material of the welded portion was confirmed with a magnifying glass, it was confirmed that the material was 100% alloyed.
[0056]
As described above, according to the welding method and the welding apparatus of the present invention, the metal member or the welding material is heated to a predetermined temperature in advance, and the subsequent main welding is conventionally applied. It is possible to perform the process with a very low current and in a short time as compared with the condition described above. For this reason, during the temporary attachment of the welding material and the subsequent main welding, oxides are hardly formed on the metal member to be repaired, and the beautifully repaired metal member having minute damage is repaired. Becomes possible.
Therefore, it is of course suitable for repairing molding dies, press dies, jigs and the like, but is particularly suitable for repairing daily necessities and jewelry, etc., in which the finish after repair is a problem.
[Brief description of the drawings]
FIG. 1 is a process diagram schematically showing one embodiment of a welding method of the present invention.
FIG. 2 is a circuit diagram schematically showing an example of a power supply constituting a preheating / temporary attaching section in the welding apparatus of the present invention.
FIG. 3 is a partial circuit diagram schematically illustrating an example of a power supply constituting a welding portion in the welding apparatus of the present invention.
[Explanation of symbols]
2 ... welding material, 2a ... tip, 3 ... metal member, 4 ... primary electrode (for resistance welding), 5 ... secondary electrode, 6 ... welding material (temporarily attached by incomplete melting), 7 ... protection Gas, 9 welding site, 10 repair site, 11 primary electrode, 13 welding metal, 14 arc welding torch (tungsten electrode), 18, 19 welding equipment, 31 AC / DC converter, 32 ... Current control unit, 33: discharge time control unit, 34: power unit.

Claims (8)

The metal member to be repaired is pre-heated by applying a short time to the metal member,
On the preheated metal member, a welding material at least partially melted is spotted and temporarily attached,
A welding method, wherein a welding material temporarily attached to the metal member is completely melted by arc discharge, and a repaired portion of the metal member is fully welded. The welding electrode is detachably attached to the electrode body, and a primary electrode and a secondary electrode, which are fitted in a state where the tip protrudes, are electrically connected to the metal member to perform the preheating,
Then, the primary electrode is separated from the metal member to generate an arc, the tip of the welding material is melted, and the tip of the melted welding material is pressed against the metal member to perform the temporary attachment. The described welding method. The welding method according to claim 1, wherein the preheating and the tacking are performed by applying a current of 0.1 to 1000 A in a pulse form for 0.1 to 5.0 seconds. The welding method according to any one of claims 1 to 3, wherein the temperature of the metal member and the welding material is increased to 20 to 1000C by the preheating. The metal member is a mold steel, cast steel, aluminum, copper, magnesium, gold, silver, or any one of platinum, or an alloy, oxide, carbide, or nitride containing at least one of these metals. The welding method according to claim 1. The welding method according to any one of claims 1 to 5, wherein the main welding is performed by applying a current of 0.1 to 1000 A in a pulse form for 0.001 to 1.0 seconds. The welding material may be any one of mold steel, cast steel, aluminum, copper, magnesium, gold, silver, platinum, or zinc, or an alloy, oxide, carbide, or nitride containing at least one of these metals. The welding method according to any one of claims 1 to 6, comprising a material. A welding material is attached to the electrode body in a detachable and protruding manner with its tip protruding, a primary electrode, a secondary electrode electrically connected to a metal member, and a 0.1-1000 A electrode between these electrodes. A preheating / temporary attachment unit having a power supply for supplying a pulse of current for 0.1 to 5.0 seconds;
A primary electrode that is close to the metal member, a secondary electrode that is electrically connected to the metal member, and a current of 0.1 to 1000 A is pulsed between the pair of electrodes for 0.001 to 1.0 seconds. A welding part having a power source, and a main welding part for completely melting a welding material temporarily attached by arc discharge and welding a repaired portion of the metal member.

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