JP2004160461A - Method and device for welding metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily perform repair welding without requiring skill in a method and a device for performing the repair of cladding by welding of portions of wear or chipping in various metal dies and various metal tools of dies for resin molding and dies for press. <P>SOLUTION: A tip of a welding rod and electrode D is directly brought into contact with a repair part Wa of a metal W to electrify. The tip of the welding rod and electrode D is melted by the resistance heat generated in a contact surface of the tip of the welding rod and electrode D with the repair part Wa of the metal, and the repair part is cladded by the resistance welding. The energization is the pulse energization to intermittently perform the energization to the welding rod and electrode D. When the welding is started, the energization time for each pulse is set to be small and is increased gradually with the elapse of time. After the predetermined time, the energization time for each pulse is set to be constant. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for welding a metal material, and more particularly, to a method and an apparatus used for general welding of precision parts and building materials, and particularly to a resin molding die and a press die. The present invention relates to a method and an apparatus for overlay-welding and repairing parts such as wear and defects in various metal molds and various metal tools.
[0002]
[Prior art]
In manufacturing sectors such as the shipbuilding industry, the automobile industry, and the home appliance industry, welding technology has advanced, and robotic unmanning and precision welding have been developed.
However, ultra-precision welding technology capable of repairing and processing precision molds is lagging behind.Therefore, if the mold is damaged, the mold must be newly started without repair. did not become.
[0003]
Therefore, in recent years, a resistance heat welding machine for repair has begun to be developed in the mold industry.For example, a paste-like welding agent is applied to a repair portion, a tungsten alloy electrode is pressed, and electricity is applied. There has been provided a repair welding machine that repairs a repaired portion by melting a welding agent, and a repair welding machine that uses powder or thin foil made of iron or an iron alloy instead of a paste-like welding agent.
These resistance heat welding machines generate almost no ultraviolet light compared to welding machines that generate arcs, so they can be welded with the naked eye, and can easily control heat, and can be used at the welding points of molds. Since the welding operation can be performed by contacting the electrodes, there is an advantage that skill is not required.
[0004]
However, the paste-type welding agent has a disadvantage that the fine powder of iron powder scatters as a spark and the paste dries due to heat.When using the iron powder welding agent, the spark is more than the paste-like welding agent. There is a defect that the iron powder splatters and spills from the repaired portion and the iron powder is oxidized, and the method of attaching the iron foil to the repaired portion has a disadvantage that it is easily peeled off.
[0005]
On the other hand, a welding machine that generates an arc to melt both a welding portion and a welding rod to perform welding has been used for a long time in the construction industry, shipbuilding industry, and the like.
In arc welding, for example, a tungsten electrode is attached to a torch, and an arc is generated by opening the electrode and the welding point by about 2 mm in a state where the welding point is shielded with an inert gas such as argon gas. There is a so-called argon welding method in which a welding rod is inserted to melt the welding rod.
[0006]
This argon welding is relatively accurate and can be used for repairing molds. However, the welding machine that generates an arc generates terrible light (ultraviolet light), so it is impossible to work with the naked eye. It is. Also, if the distance between the electrode and the welded portion is smaller than 2 mm, the welded portion is melted more than necessary, and if the electrode comes into contact with the welded portion, the welded portion is depressed or destroyed. While checking through the deflection glass on the protective surface, the electrode and the welding point must be moved while maintaining a distance of 2 mm, and the welding rod must be fed into the arc with one hand, requiring a high degree of skill and intuition. Become.
Further, in a shape having many irregularities such as a mold, it is extremely difficult to maintain a distance of 2 mm while moving along the irregularities without a torch having electrodes attached thereto.
[0007]
In addition, there is also a welding method by brazing, but the use of non-ferrous metal silver wax as a welding agent causes a sense of incongruity with a different hardness and color from the welding point, and also preheating the welding point or the entire mold Therefore, it is not suitable for repairing a precision mold.
[0008]
Further, conventionally, in Japanese Patent Application Laid-Open No. 6-269936, a mold repairing apparatus using a consumable electrode type arc welding as shown in FIG. 13 has been proposed. The mold repair apparatus 1 applies a pulse voltage to the electrode rod D gripped by the rotary chuck 2, rotates the electrode rod D, and ejects the inert gas G from the nozzle 3 to perform welding at the repair location. Has been.
[0009]
[Problems to be solved by the invention]
The welding method shown in FIG. 13 has an advantage that, unlike the argon gas welding described above, there is an advantage that it is not necessary to carry a work of sending a welding rod separately from the welding torch between the electrode and the repair part, but the welding rod is used. The rotation of the electrode rod D causes various problems.
That is, looking at the same point of the repaired part, since the electrode rod D is rotating, it is not continuously welded, the electrode rod D rotates once, and the welded portion is welded again while hot, and this is Repeatedly, a state in which minute welds are accumulated. Therefore, when the surface is broadened over a wide area, the plane becomes rough. Conversely, when the repaired portion is at a sharply pointed tip position, the rotation of the electrode rod D causes the electrode rod to escape from the sharply sharpened tip portion, so that there is a problem that accurate welding repair cannot be performed. In addition, since the electrode rod D is held by the rotary chuck 2, a general-purpose electrode rod cannot be used and a dedicated electrode rod is required, and it is not necessary to use the same material as the electrode rod called the common material. It becomes possible.
[0010]
In addition, in the above-mentioned welding, since intermittent welding is performed by a pulse voltage, it is necessary to weld the same portion many times when thickening is made, so it takes time, and when thickly building up, Not suitable.
[0011]
Further, in normal arc welding, the gap between the electrode tip and the welded portion must be maintained at about 2 mm, but there is a problem that an unskilled person cannot easily perform the welding, and this problem has been solved by the above-described apparatus. Absent. Further, at the start of welding work, it is necessary to once contact the electrode tip with the repaired part, and it is necessary to withdraw from the welded part immediately after contact and leave the above-mentioned about 2 mm gap as non-contact. However, it cannot be easily learned without skill, and the above-mentioned apparatus does not solve this problem.
[0012]
The present invention has been made in view of the above-described problems, and has as its object to enable high-precision welding to be easily performed without skill.
[0013]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention provides a method in which the tip of a welding rod / electrode is brought into direct contact with a metal material and energized, and the resistance heat generated on a contact surface between the tip of the welding rod / electrode and the metal material. A method for welding a metal material is provided, wherein the tip of the welding rod / electrode is melted, and the buildup is performed by resistance welding.
[0014]
With the above configuration, the electrode, which is also used as a welding rod, is brought into contact with the work and melted by resistance heat, so that the worker does not care about the distance to the work as in arc welding and is important for the finish. The work can be performed intensively only on the degree of welding, so that the welding workability can be improved, and no arc is generated and the protective surface is unnecessary.
[0015]
The power supply to the welding rod / electrode is intermittently performed by pulse power supply, and the power supply time per pulse and the pulse interval are controlled.
[0016]
Since the energization for overlay welding is performed intermittently in this manner, heat is not excessively increased and optimization is performed, and only the melting portion at the tip of the wire is melted. This also prevents interruption of energization due to overheating.
Also, by controlling the amount of current at the time of each energization, optimal control of heat can be performed.
[0017]
Specifically, the current value of the energization is set to 30 to 1500 amps, the energization time per one pulse of the energization is set to 0.00001 to 5.0 seconds, and the energization suspension time between the pulses is set to 0.1. 00001 to 0.5 seconds.
It is preferable that the applied voltage value be 1 to 10 V.
[0018]
At the start of welding, the energizing time per pulse of the energizing is set to be a minute time, and the energizing time per pulse is gradually increased as time elapses. After a certain period of time, the energizing time per pulse is constant.
[0019]
As described above, the energizing time per pulse is not made to flow at a constant time, but is initially set to a shorter energizing time than the above-mentioned constant energizing time, and the energizing time per pulse is gradually increased. At a certain time, at the start of welding, it is possible to prevent the concentrated current from bouncing off the wire and damaging the work before the wire fits into the contact surface of the work. And stable welding can be performed.
In addition, in the run-up energizing period from the start of welding until the energizing time per pulse becomes constant, not only the energizing time per pulse is increased proportionally, but also the current is automatically sensed and occasionally detected. It is also preferable to interpose a pulse having a long energizing time or a pulse having a short time.
[0020]
The current supplied to the welding rod / electrode directly uses an alternating current as a power source.
As described above, when the alternating current as the power supply is supplied to the welding rod / electrode without passing through the capacitor, the structure is simple and the cost is good. In this case, the pulse control of the alternating current is performed by a phase control method using a computer.
Alternatively, if the alternating current as the power supply is converted to direct current and then amplified to high-frequency alternating current by an inverter, and the energizing time per pulse is further minimized, and the time interval between pulses is shortened, excessive heating of the welding surface is prevented. It is possible to obtain a precise and clean welding surface while preventing the occurrence. Note that the upper limit of the AC frequency is 100 kHz, and the lower limit is 20 Hz.
In addition, the capacitor may be used with an intervening capacitor. In this case, since the energization is performed intermittently as described above, the energy stored in the capacitor can be saved and the current can be reduced. Can be used as the welding rod / electrode feed time and the capacitor charging time.
[0021]
The welding rod / electrode is continuously supplied to the metal material in the form of a wire, and the supply speed can be adjusted to a required constant speed or speed.
In this way, by making the welding rod / electrode in a wire shape, the feeding of the welding rod / electrode becomes easier and the operability is improved.
[0022]
The contact surface between the tip of the welding rod and electrode and the metal material is surrounded by a shield gas to prevent oxidation of the resistance welding portion.
Note that, as the shielding gas, an inert gas such as an argon gas, a helium gas, a carbon dioxide gas, a nitrogen gas, a mixed gas of these gases, or a mixed gas of argon and oxygen is used.
[0023]
By using various kinds of inert shielding gas, even if the welding conditions differ depending on the material of the wire and the work, etc., the welding part is securely covered and cut off from the outside environment, and the welding part is oxidized. In addition, the surface of the repaired surface can be improved by preventing nitriding.
[0024]
The present invention also provides a welding rod / electrode which is build-up welded to a metal material by resistance heat welding, means for holding the welding rod / electrode and continuously feeding the metal material, And a power supply control means for controlling a power supply time and a power supply amount.
[0025]
The cross-sectional shape of the welding rod / electrode has a shape such as a circle, an ellipse, an oval, a flat shape, a gourd, a triangle, a concave, a U-shaped or a V-shaped corresponding to a metal material. The structure is such that the electrodes can be closely attached.
[0026]
In this way, by preparing a variety of cross-sectional shapes of the wire, an electrode wire having a circular or elliptical cross-section is normally used, while a welding rod having a convex portion or a sharp corner is used. The shape of the cross section of the gourd-shaped, concave, U-shaped, etc. is used by applying the dent. Conversely, when the welded portion is a concave or L-shaped part, the cross-section of the welding rod is triangular or It can be used in a V-shape or the like with its pointed portion applied to improve welding accuracy.
[0027]
The welding rod / electrode is made of wire,
The means for holding the welding rod and electrode and continuously supplying the metal material includes a feeding motor, and a wire feeding roller or a wire feeding gear roller driven by the motor,
As an energizing means for connecting the welding rod / electrode to a power source, an electrode nozzle is provided at a position in contact with the wire fed by the wire feed roller or the wire feed gear roller, and is provided on the electrode nozzle. The wire is slidably passed through the through-hole, is advanced to the metal material, and is energized to the wire.
[0028]
With the above configuration, the wire, which is both a welding rod and an electrode, can be stably fed to the repair location by the wire feeding roller or the wire feeding gear roller driven by the motor. In addition, since the wire is slidably brought into contact with the through hole of the electrode nozzle to energize, it is possible to easily energize the moving wire.
[0029]
Further, the wire feed roller includes a pair of gear rollers, and a wire insertion groove through which the wire is inserted in a press-contact state is provided at a part of a boundary surface where each gear roller is engaged, and the gear roller rotates in a state where the gear rollers are engaged. By doing so, it is preferable that the wire is fed. Then, even if the gear rollers are slightly abraded, the meshing between the gear rollers is maintained, so that the gear rollers can press and feed the wire without idling with each other.
As another driving method for feeding the wire, a structure in which the wire sending section is reciprocated by a solenoid may be used. In this case, when the wire sending section moves in the wire sending direction, the wire sending section moves. When the wire is moved in the direction opposite to the wire sending direction, the wire holding may be released to prevent the wire from returning. Instead of the reciprocating motion by the solenoid, reciprocating motion by a cam driven by a motor may be used.
[0030]
An inert gas such as an argon gas, a helium gas, a carbon dioxide gas, a nitrogen gas, a mixed gas of these gases, or a mixed gas of argon and oxygen is supplied as a shielding gas to a contact portion between the welding rod / electrode and the metal material. ing.
Specifically, a gas cover that surrounds the outer periphery of the electrode nozzle with a shield gas flow path is provided, and a means for supplying the shield gas to the shield gas flow path, and the nozzle and the welding rod / electrode are provided by a nozzle. Means for injecting a shielding gas at a spot in contact with the metal material may be considered.
In particular, in the means for surrounding the outer periphery of the electrode nozzle with the gas cover, it is assumed that the gas cover becomes an obstacle when welding a corner or the like, but in the case of means for jetting the shielding gas with the nozzle, This is preferable because a gas cover is not required.
[0031]
Provide a hand-type holder equipped with the wire feeding motor, wire feeding roller or wire feeding gear roller, electrode nozzle, gas cover, and detachably electrically connect the main body with power supply means and the holder. The configuration is such that
A capacitor and a sub energization control unit are mounted in the holder, and power is supplied from the capacitor to the wire feed motor and the electrode nozzle, and energization control is performed by the sub energization control unit.
[0032]
With the above configuration, while the hand-type holder is attached to the main body, the capacitor on the holder side is charged from the power supply means, and at the time of work, the holder is removed from the main body and it is wireless, and welding is performed according to the sub energization control means And workability is dramatically improved.
[0033]
The energization control means controls the energization time, pulse interval, and energization amount per pulse when the pulse is applied to the welding rod / electrode, and starts welding when the welding rod / electrode is brought into contact with the metal material. The power supply time of the pulse is made minute, and the power supply time per pulse is gradually increased so that the power supply is performed, and the power supply control to the wire feeding motor and the motor rotation speed control are performed.
[0034]
The power supply control means is connected to a computer via a power supply means and the power supply means.
If a computer is used to set the control of the power supply control means by connecting to a computer, for example, a simple setting operation can be performed using a graphical user interface.
[0035]
The welding rod / electrode is made of the above-mentioned metal material and the same material or iron, iron and steel, stainless steel, beryllium, copper alloy, aluminum alloy, zinc alloy, casting, nickel, nickel alloy, and has a diameter of 0.2 mm to 5 mm. On the other hand, the metal material which is build-up welded by the welding rod / electrode comprises a resin mold, a rubber mold, a glass mold, a die cast mold, a press mold, and a metal roller.
[0036]
If a wire of the same material as the material of the work (metal to be repaired) is used for the wire, the repaired part and the other part do not differ from each other in terms of metal material. Problems such as peeling of parts can also be prevented. In addition, since various materials can be used for the welding rod and electrode, the work that can be repaired can also be applied to various dies, and can be applied to various tools and gears in addition to the dies.
[0037]
At the end of the welding operation, the wire is sent out and a current is supplied for a certain period of time to control the wire to be easily blown.
[0038]
When the welding is stopped after suddenly turning off the power, the wire will remain welded to the work, and if it is forcibly peeled off, the repaired surface may be damaged, but as described above, if the wire is sent out and a small current flows, In addition, it is possible to easily perform the fusing separation between the repaired portion of the work and the wire without damaging the repaired surface.
[0039]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a repair welding device 10 according to a first embodiment of the present invention, which includes various molds such as a resin mold, a rubber mold, a glass mold, a die cast mold, and a press mold, a gear, and the like. It is used for welding and repairing various mechanical parts such as metal rollers and the like, wear and loss of cutting tools and the like. The repair welding apparatus 10 includes a main body 11 containing control means and the like, a gun-type hand-type holder 12 for welding with a wire D serving as a welding rod and an electrode, and a gas cylinder 25. The feed is supplied to the holder 12 via the tube 28, the main body 11, and the tube 22.
[0040]
The holder 12 shown in FIGS. 2A and 2B incorporates a motor 13 and a pair of wire feeding rollers 14a and 14b inside a housing 12a, and an electrode nozzle 16 at a tip 12b on the welding side. A gas cover 17 that covers the electrode nozzle 16 is attached. Further, a guide holder 19 that holds and guides a wire D having a circular cross section that serves as a welding rod and an electrode is attached to the rear end portion 12c.
The grip 12d of the worker is projected downward from substantially below the center of the housing 12a.
[0041]
The rollers 14a and 14b are composed of a motor drive roller 14a and a driven roller 14b. The driven roller 14b is brought into contact with the wire D by urging the driven roller 14b with a spring (not shown). That is, the rotating shaft 14d of the roller 14a is connected to the motor shaft 13a of the motor 13 located at the lower portion by the coupling 15, and the driving of the motor 13 causes the roller 14a to rotate, and the other roller 14b also follows via the wire D. Let me.
When a large torque is required for feeding the wire, a large motor may be positioned above the rollers 14a and 14b to drive the roller 14a, or the motor may be applied to both of the opposing rollers. Both rollers may be driven in connection. If a larger torque is required, a pair of rollers for one-side drive or both-side drive may be provided in a plurality of rows in the housing.
[0042]
Further, the rollers 14a and 14b are installed at positions where the center of the gap 14c between the rollers is slightly offset left and right or up and down with respect to the center of the electrode nozzle 16 to be described later, and the feeding direction of the wire D is changed. The wire D is slightly eccentric with respect to the axis of the electrode nozzle 16 so that the wire D reliably contacts the peripheral surface of the through hole of the electrode nozzle 16.
[0043]
As a modified example of the rollers, as shown in FIGS. 4A and 4B, a pair of gear rollers 14a 'and 14b' may be used instead of the wire feeding rollers 14a and 14b.
Each of the gear rollers 14a 'and 14b' has a thread winding shape, and is provided with concave and convex portions 14a-1 'and 14b-1' on upper and lower flanges, and is formed by central recesses 14a-2 'and 14b-2'. The space is an insertion passage to which the wire D is pressed. The wire D is fed by rotating while the gear rollers 14a 'and 14b' mesh with each other. Then, even if the concave and convex portions 14a-1 'and 14b-1' of the gear rollers 14a 'and 14b' are slightly abraded, the meshing of the gear rollers 14a 'and 14b' is maintained, so that the wire D Can be fed by pressing.
[0044]
The roller driving motor 13 built in the grip portion 12d is a DC motor, which is connected to the main body 11 via a motor lead wire 24, which will be described later, and which is clockwise or counterclockwise depending on the direction of the supplied DC current. In addition to enabling forward and reverse rotation, the rotation speed can be varied by changing the voltage value. Specifically, when the motor 13 is rotated in the direction of the arrow in FIG. 2A, the wire D moves forward, and when the motor 13 is rotated in the direction opposite to the direction of the arrow in the diagram, the wire D retracts. The forward or backward feed speed changes.
[0045]
The electrode nozzle 16 is formed of a conductive material. As shown in FIG. 2C, a wire through hole 16a is provided at the center, a flange portion 16b is provided at a base portion, and a conical nozzle portion 16c is provided at a tip side. Provided. The shape of the nozzle portion 16c is not limited to a conical shape, and may be a cylindrical shape. A funnel 16h is recessed at the center of the mounting side surface 16d of the flange 16b to guide the wire D into the through hole 16a. The funnel 16h is coated with an insulating material. Further, a gas joint connecting portion 16e is provided on a part of the side surface of the flange portion 16b, and a gas hole 16g communicating from the pipe joint connecting portion 16e to the protruding surface 16f side of the nozzle portion 16c is provided.
[0046]
A conductive pipe joint 26 is connected to the pipe joint connection portion 16e, and the tube 22 is connected to the pipe joint 26. A lead wire 23 is passed through the inside of the tube 22, and the lead wire 23 is connected to a pipe joint 26. Therefore, electric power supplied from the main body 11 is supplied from the lead wire 23 to the electrode nozzle 16 which is a conductor through the pipe joint 26. The power supplied to the electrode nozzle 16 is such that the wire D passing through the through-hole 16a comes into contact with the inner surface of the through-hole 16a, and power is supplied to the wire D. The electrode nozzle 16 has various types in which the inner diameter of the through-hole 16a has a size corresponding to the outer diameter of the wire D to be used, and the electrode nozzle 16 is appropriately replaced according to the diameter of the wire D to be used.
[0047]
A nozzle cover 18 is attached to the nozzle portion 16c of the electrode nozzle 16 so as to cover a central portion from the flange portion 16b. The nozzle cover 18 has a generally cylindrical shape with a step, and has a total of eight gas ejection ports 18a provided in two rows in the axial direction at 90 ° intervals on the outer peripheral wall. By providing the gas ejection port 18a in this way, as shown in the direction of the arrow in the figure, the shield gas discharged from the gas hole 16g of the electrode nozzle 16 once fills the inside 18b of the nozzle cover 18, The gas is uniformly discharged from the four gas outlets 18a.
[0048]
The outer peripheral surface and / or the inner peripheral surface of the nozzle surface 16c of the electrode nozzle 16 protruding from the nozzle cover 18 and the tip surface 18c of the nozzle cover 18 are made of insulating material such as ceramic to prevent arcing during welding work. Covered with body Z.
[0049]
The power supply to the wire may be performed using a power supply brush instead of the above-described contact between the electrode nozzle 16 and the wire D. For example, a power supply brush may be provided in a wire supply path between the electrode nozzle 16 and the rollers 14a and 14b to make contact with the wire to supply power. When the power supply brush is provided as described above, the electrode nozzle 16 and the nozzle cover 18 may be formed of an insulator.
[0050]
Further, the gas cover 17 is formed of a cylindrical insulator, and is provided on the front portion 12b of the holder 12 so as to cover the electrode nozzle 16 and the nozzle cover 18 with the tip of the electrode nozzle 16 being slightly exposed. It is attached by screwing or fitting, and during welding, the welding location by the wire D is covered with a shielding gas discharged from the gas ejection port 18a of the nozzle cover 18, so that an optimum welding environment is obtained. .
[0051]
On the other hand, the guide holder 19 attached to the rear end portion 12c of the holder 12 is formed of an insulating material having sufficient rigidity to protect and hold the wire D in a long tubular shape. Alternatively, the size is set to correspond to the standard length of the electrode rod. The front end 19a of the guide holder 19 is located immediately before the gap 14c between the rollers 14a and 14b inside the holder 12, so that the wire D inserted from the rear end 19b is reliably sent to the gap 14c. I have.
[0052]
The tube 22 connecting the holder 12 and the main body 11 is formed of an insulating material, and as shown in FIGS. 4A and 4B, a lead wire 23 for energization and a lead wire 24 for the motor are passed through the inside. The gap 22b between the tube inner surface 22a and the lead wires 23, 24 is used as a shield gas flow path. The connection side of the tube 22 with the holder 12 is connected to the motor 13 by branching only the motor lead wire 24 inside the holder 12, and the tube 22 and the current supply lead wire 23 are connected to the electrode nozzle as described above. 16 is connected. When the power supply brush is used, the arc lead wire 23 is connected to the power supply brush.
[0053]
Further, as a modification of the means for supplying the shielding gas to the welding surface, a structure shown in FIG. 5 may be used. Specifically, the nozzle cover 18 is eliminated, and the rear end 26b 'of the gas flow tube 26' formed in a required bent shape is connected to the tube 22, while the front end 26a 'is connected to the front end of the nozzle portion 16c of the electrode nozzle 16. And the shield gas is injected to the welding surface. This is preferable because the nozzle cover 18 does not hinder the welding operation of the corner portion.
[0054]
The main body 11 has a box shape as shown in FIG. 1 and is provided with a main switch 30a and a level meter 30j, and a flow meter 31 is attached so that the flow rate of the shielding gas can be checked.
[0055]
As shown in FIG. 6, inside the main body 11, a motor power supply unit 32a, a control power supply unit 32b, and a welding power supply unit 32c connected to the ground line 29 are connected to a power supply unit (power supply unit) 31 that supplies power from an AC external power supply. Each of them is connected so that the required power is output from the power supply unit. The power supply unit 31 only has a function of distributing the AC power to the power supply units 32a, 32b, and 32c, but may include an electrolytic capacitor. The device control unit 33a to which power is supplied from the power supply unit 31 transmits and receives various signals to and from the motor control unit 33b and the power supply control unit (power supply control unit) 33c, and also turns on the foot switch 20 of the main body 11 and the like. Is input, and the output status of the welding power source and the like are output to the level meter 30j. Further, the device control unit 33a also outputs an open / close signal of the electromagnetic valve 35 for discharging the shield gas.
The gas tube 22 downstream of the solenoid valve 35 is provided with a regulator 36 for adjusting pressure.
[0056]
If various controls are performed on the computer 11 by connecting a personal computer or the like, the setting operation is simplified by the graphical user interface, and the operability is improved. Further, in order to enhance operability, workability, and the like, voice guidance such as an operation procedure may be output from the device control unit 33a. Instead of providing the foot switch 20, a hand switch may be provided on a grip portion of the holder 12 or the like and connected to the main body 11.
[0057]
The welding power and the motor power are also output from the welding power supply 32c and the motor power supply 32a.
The power output from the welding power supply unit 32c to the conducting lead 23 is output with a pulse width controlled by PWM (Pulse Width Modulation / Pulse Width Modulation) by modulating the power of the power supply unit 31 with the welding power supply unit 32c. Like that.
The motor control unit 33b performs feedback control of the output state of the motor power supply unit 32a that outputs a current to the motor lead wire 24, and performs various operations related to driving of the motor 13 of the holder 12 from the device control unit 33 according to the set contents. A signal is sent. The motor control unit 33b normally outputs motor power so as to rotate the motor 13 in accordance with various setting situations.
[0058]
Next, the welding operation by the welding device 10 will be described with reference to the timing chart of FIG.
When the main switch 30a is turned on and then the foot switch 20 is turned on, an opening signal of the solenoid valve 35 is output from the device control unit 33a, the solenoid valve 35 is opened, and the shielding gas is led out from the gas cylinder 25 to the tube 22. I have to.
Then, 1 to 2 seconds (* 1) later, the wire D is sent from the tip of the electrode nozzle 16 at a required speed, and 0.1 to 0.5 seconds (* 2) after the start of sending the wire D, Is performed in a pulsed manner. At this time, the energizing time per pulse is set to a very short time of 0.00001 to 0.005 seconds in the approach energizing period (* 3) from the start of welding to a main energizing period (* 4) to be described later. At the same time, the energizing time per pulse is gradually increased. The energization suspension time between pulses is 0.001 to 0.02 seconds.
[0059]
By the energization during this run-in energization period (* 3), the contact surface between the wire D and the work W is adjusted, and stable welding is performed during the main energization period (* 4) where the energization time per pulse described later is constant. So that you can do it.
In addition, since the power is not continuously supplied, but is supplied intermittently in a pulsed manner, energy can be saved.
[0060]
Next, the energization time per pulse (* 4-1) is a constant value between 0.00001 and 5.0 seconds, and the pause time between pulses (* 4-2) is 0.00001-0.5 seconds. The welding of the wire D to the workpiece W is performed in the main energizing period (* 4) having a constant value between. The current value for energization is in the range of 30 to 1500 amps, and is 400 to 500 amps in this embodiment, and the voltage value is 1 to 10 V.
As described above, the main power supply period (* 4) is repeated while the foot switch 20 is turned on. The dotted line in FIG. 8 represents an AC waveform, and the power to the wire D is supplied by pulse control using a phase control method using a computer.
[0061]
When the foot switch 20 is turned off, after the power is turned off, the wire D is sent out for 0.1 to 1.0 seconds (* 5) to prevent welding of the wire, and the power supply end buzzer is turned on for 1 to 2 seconds. Then, a fusing current (* 6) is applied for 0.01 to 0.5 seconds so that the wire D is easily blown.
Lastly, even after the fusing current (* 6) is turned off, the shielding gas is blown for about 1 to 3 seconds afterwards in order to prevent blackening of the work surface, and then the electromagnetic valve 35 is closed to blow out the shielding gas. The suspension is delayed.
[0062]
Next, a specific welding procedure will be described.
In order to perform repair welding by the repair welding apparatus 10, first, a shield gas suitable for the material of the repair work and the wire D and welding conditions is selected. Usable shielding gases include argon gas, helium gas, carbon dioxide gas, nitrogen gas, a mixed gas of these gases (mixed gas of argon gas and carbon dioxide gas, mixed gas of argon gas and helium gas) or argon gas. There is a mixed gas of oxygen and the like, and a gas cylinder 25 filled with an appropriate gas from among them is connected to the main body 11 through a tube 28. The flow rate of the gas output to the holder 12 can be adjusted while checking the flow meter 31 with the flow rate adjustment valve 32 of the main body 11.
[0063]
Also, select the material of the wire used for welding. Usable materials include repair work and common materials, such as iron, steel, stainless steel, beryllium, copper alloys, aluminum alloys, zinc alloys, castings, nickel, and nickel alloys. Is also preferably used. As the shape of the wire D, a diameter of 0.2 mm to 5 mm is applicable, and a wire having a diameter of 0.6 to 0.8 mm is used in the present embodiment. The electrode nozzle 16 of the holder 12 is adapted to the above outer diameter, and the selected wire D is inserted from the rear end 19 d of the guide holder 19 so as to protrude from the front end of the electrode nozzle 16. The wire D is not limited to the above-mentioned general-purpose wire, but may be a wire dedicated to obtaining optimum welding conditions by changing various materials.
[0064]
Further, the ground wire 29 is connected to a work W having abrasion or a defect such as a precision component to be repaired, a building material, a mold, or the like. Items that can be repaired include various molds such as resin molding and rubber molding, mechanical parts made of various metals such as gears and metal rollers, and blades.
[0065]
After the above-mentioned preparation work is completed, the main switch 30a of the main body 11 is turned on, and then the welding conditions are set by various switches (or a connected personal computer) in consideration of the material of the work or the like.
As shown in FIG. 7A, the worker holds the holder 12 and presses the wire D protruding from the tip of the nozzle cover 18 attached to the electrode nozzle 16 against the defective portion Wa for repairing the work W. When the foot switch 20 is turned on in this state, welding starts according to the time chart of FIG.
[0066]
First, energization is performed by minimizing the energization time per pulse, which is the approach energization period (* 3), and after the wire D is adjusted to the work W, one pulse is applied to the wire D in the main energization period (* 4). When the current is applied so that the current application time (* 4-1) is constant, as shown in FIG. 7B, the wire D and the work W are simultaneously melted and the overlaying portion Wb for filling the defective portion Wa is formed. Is formed.
At this time, since the wire D is sent out from the tip of the nozzle cover 18 from the wire feed rollers 14a and 14b, the wire D is pressed against the work W and the contact is stabilized, so that the operator can fix the repaired portion (the defective portion Wa). It is only necessary to concentrate on moving the holder 12 along the line, workability is greatly improved, and repair welding can be easily performed as shown in FIG. 7 (C).
[0067]
Finally, by turning off the foot switch 20, the wire D is sent out (* 5) and the fusing current (* 6) after the above-mentioned energization is turned off, so that the wire D is easily blown, and the holder 12 is moved. By lifting, the wire D and the overlay portion Wb are easily blown.
[0068]
7A to 7D, the contact surface between the tip of the wire D and the workpiece W is surrounded by a shield gas G made of inert gas, so that the material of the wire D and the workpiece W may vary. Even if the welding conditions are different, it is possible to reliably cover the welded portion and shield it from the outside environment, prevent oxidation and nitriding of the welded portion, and improve the finish of the repaired surface.
[0069]
FIG. 9 shows a first modification of the wire.
Although the wire D of the first embodiment has a circular cross section, in the present modification, the electrode wire 40 has a gourd-shaped cross section provided with a concave portion 40a having a narrow width at the center in the longitudinal direction.
As described above, by using a wire 40 serving as a welding rod having a gourd-shaped cross section, when the welding portion is a sharp point, the sharp portion is stably fitted in the concave portion 40a of the wire 40. Therefore, the wire 40 can be stably brought into contact with a sharp work, so that workability can be improved and welding accuracy can be improved.
[0070]
FIG. 10 shows a second modification of the wire.
The wire 50 of the present modification has an elliptical cross section and a roughened surface 50a for preventing slippage on the side surface.
In this case, when the welding work is performed by bringing the wire 50 serving as a welding rod into contact with the welding location, the wire 50 is less likely to slip with respect to the welding location due to the rough surface portion 50a. There is an advantage that it is easy to hit
[0071]
FIG. 11 shows a first modification of the nozzle cover.
The nozzle cover 18 'of this modification has a configuration in which an inclined surface 18h' is provided on the distal end side and the wire D is sent out from a through hole in the inclined surface, and the distal end apex 18i 'is brought into contact with the work W. In this state, the state in which the wire D protrudes from the inclined surface 18h 'can be maintained. Therefore, the worker can perform the welding operation by moving the holder 12 while keeping the tip 18i 'in contact, and the stability is very good.
Needless to say, the electrode nozzle inside the nozzle cover 18 'also has the above-mentioned shape with the change in the shape of the nozzle cover 18'.
[0072]
FIG. 12 shows a second modification of the nozzle cover.
The nozzle cover 18 "of this modified example has a concave cross-section, and sends out the wire D from the tip. The wire D is welded so as to be loaded in the direction of the arrow, so that the wire D comes out of the notch 18j". There is no.
[0073]
FIG. 13 shows a second embodiment.
In the present embodiment, a hand-type holder 12 'is detachably electrically connected to the main body 11' to be wireless.
[0074]
A capacitor 62 and a sub-energization control unit 61 are mounted on the holder 12 ′, and a capacitor 62 in the holder 12 ′ is mounted on the charging stand 60 connected to the power supply unit 31 inside the main body 11 ′. In operation, the holder 12 'is detached from the charging stand 60 and used.
The power is supplied from the capacitor 62 to the wire feeding motor 13 and the electrode nozzle 16, and the power supply is controlled by the sub power supply control unit 61.
Note that the other detailed configuration is the same as that of the first embodiment, and a description thereof will not be repeated.
[0075]
With the above configuration, the capacitor 62 on the holder 12 'side is charged while the hand-type holder 12' is attached to the charging stand 60 of the main body 11 '. The welding can be performed according to the sub-energization control means 61, and the workability is greatly improved.
[0076]
【The invention's effect】
As is apparent from the above description, according to the present invention, since the wire serving as the welding rod / electrode is brought into contact with the work and melted by the resistance heat, the operator can maintain the distance between the welding rod / electrode and the work. It is not necessary to open the space, and the work can be performed intensively only on the degree of welding, so that the welding workability can be improved, and no arc is generated and the protective surface is not required. And since the holder is stabilized by sending out the wire just by holding the holder, the operator need only concentrate on moving the holder along the repaired part, and the workability is further improved.
In addition, since the power supply to the wire is intermittently performed by pulse power supply, heat is optimized, and high-precision welding without oxidation, sink mark, and distortion can be performed.
Further, the energizing time per pulse at the start of welding is minute, and the energizing time per pulse is gradually increased as time elapses, and the energizing time per pulse is made constant after a certain period of time. In addition, it is possible to prevent the work from being damaged by flipping the wire, and to stably weld the contact surface between the wire and the work.
[Brief description of the drawings]
FIG. 1 is an overall perspective view of a repair welding device according to a first embodiment of the present invention.
2A is a plan view of a main part of a holder, FIG. 2B is a front view, and FIG. 2C is an enlarged sectional view of an electrode nozzle.
FIG. 3A is a plan view of a main part showing a modification of a wire feeding mechanism, and FIG. 3B is a front view of a main part.
4A and 4B are cross-sectional views of a gas tube in a direction perpendicular to an axis, and FIG. 4B is a cross-sectional view in an axial direction.
FIG. 5 is an enlarged view of a main part showing a modification of the means for supplying a shielding gas.
FIG. 6 is a schematic diagram showing an internal structure of a main body and a connection state.
FIGS. 7A to 7D are schematic diagrams showing a welding situation.
FIG. 8 is a drawing showing a timing chart.
FIG. 9 is a perspective view showing a first modification of the wire.
FIG. 10 is a perspective view showing a second modification of the wire.
FIG. 11 is a drawing showing a first modification of the electrode wire.
FIG. 12 is a drawing showing a second modification of the electrode wire.
FIG. 13 is a schematic view showing a second embodiment.
FIG. 14 is a drawing showing a conventional example.
[Brief description of reference numerals]
10 Repair welding equipment
11 Body
12 Holder 14a, 14b Wire feed roller
16 Electrode nozzle
17 Gas cover
18 Nozzle cover
20 foot switch
22 Gas tube
25 gas cylinder
29 Ground line
D wire (welding rod and electrode)
W Work (metal material)

Claims (16)

The tip of the welding rod / electrode is brought into direct contact with the metal material to energize it, and the tip of the welding rod / electrode is melted by resistance heat generated on the contact surface between the tip of the welding rod / electrode and the metal material, and the overlay is formed. Is carried out by resistance welding. 2. The method for welding a metal material according to claim 1, wherein the welding rod / electrode is energized intermittently by pulse energization, and energizing time and pulse interval per pulse are controlled. The energizing current value is 30 to 1500 amps, the energizing time per pulse of the energizing is 0.00001 to 5.0 seconds, and the energizing pause time between the pulses is 0.00001 to 0.5. The method for welding a metal material according to claim 2, wherein the time is set to seconds. At the start of welding, the energizing time per pulse of the energizing is set to a minute time, and the energizing time per pulse is gradually increased with time, and the energizing time per pulse is made constant after a certain period of time. The method for welding a metal material according to claim 2 or 3. The metal material according to any one of claims 1 to 4, wherein the welding rod / electrode is continuously supplied in the form of a wire to the metal material, and the supply speed can be adjusted to a required constant speed or speed. Welding method. The metal material according to any one of claims 1 to 5, wherein a contact surface between the tip of the welding rod / electrode and the metal material is surrounded by a shielding gas to prevent oxidation of a resistance welding portion. Welding method. A welding rod / electrode which is build-up welded to a metal material by resistance heat welding, means for holding the welding rod / electrode and continuously supplying it to the metal material, and energization for connecting the welding rod / electrode to a power source And a power supply control means for controlling power supply time and power supply amount. The cross-sectional shape of the welding rod / electrode has a shape such as a circle, an ellipse, an oval, a flat shape, a gourd, a triangle, a concave, a U-shaped or a V-shaped corresponding to a metal material. The welding device for a metal material according to claim 7, wherein the welding device is configured to be able to closely contact the electrode. The welding rod / electrode is made of wire,
The means for holding the welding rod and electrode and continuously supplying the metal material includes a feeding motor, and a wire feeding roller or a wire feeding gear roller driven by the motor,
As a conducting means for connecting the welding rod / electrode to a power supply, an electrode nozzle is provided at a position in contact with a wire fed by the wire feeding roller or the wire feeding gear roller, and is provided on the electrode nozzle. 9. The welding apparatus for a metal material according to claim 7, wherein the wire is slidably contacted with the through-hole, is advanced to the metal material, and is energized to the wire. An inert gas such as an argon gas, a helium gas, a carbon dioxide gas, a nitrogen gas, a mixed gas of these gases, or a mixed gas of argon and oxygen is supplied as a shielding gas to a contact portion between the welding rod / electrode and the metal material. The welding device for a metal material according to claim 9, wherein: Provide a hand-type holder equipped with the wire feeding motor, wire feeding roller or wire feeding gear roller, electrode nozzle, gas cover, and detachably electrically connect the main body with power supply means and the holder. The welding device for a metal material according to claim 10, wherein the welding is performed. The energization control means controls the energization time, pulse interval, and energization amount per pulse when the pulse is applied to the welding rod / electrode, and starts welding when the welding rod / electrode is brought into contact with the metal material. 7. A configuration in which the energizing time of a pulse is minute, the energizing time per pulse is gradually increased, and energizing is performed, and energizing control of the wire feeding motor and motor rotational speed control are performed. An apparatus for welding to a metal material according to claim 11. 13. The apparatus for welding to a metal material according to claim 12, wherein the power supply control means is connected to a computer via a power supply means and the power supply means. 12. A power supply is supplied to the wire feed motor and the electrode nozzle from the capacitor by mounting a capacitor and an energization control unit in the holder, and energization control is performed by the energization control unit. Item 14. An apparatus for welding a metal material according to any one of Items 13. The welding rod / electrode is made of the above-mentioned metal material and co-material or iron, iron and steel, stainless steel, beryllium, copper alloy, aluminum alloy, zinc alloy, cast product, nickel, nickel alloy, and has a diameter of 0.2 mm to 5 mm. On the other hand, the metal material which is build-up welded by the welding rod / electrode comprises a resin molding die, a rubber molding die, a glass die, a die casting die, a press die, and a metal roller. Item 15. An apparatus for welding a metal material according to any one of Items 14. The metal material according to any one of claims 7 to 15, wherein when the welding operation is completed, the wire is sent out and a current is applied for a predetermined time to control the wire to be easily blown. Welding equipment.

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