KR101659584B1 - Hybrid heating method and system for filler wire process - Google Patents

Abstract

The present invention relates to a hybrid heating system for resistance heating of a filler wire and a workpiece at the same time as induction heating for application to a filler wire process.
The hybrid heating system for a filler wire process according to the present invention comprises a filler wire supply device, an induction heating device for locally induction heating an end of the filler wire supplied from the filler wire supply device, Respectively. In addition, when the end of the filler wire heated by the induction heating device contacts the workpiece, the filler wire and the workpiece are heated so as to resistively heat the end of the contacted filler wire and the workpiece. And a resistance heating device for supplying electric current to the wire.
The heating system according to the present invention can locally heat the ends of the continuously supplied filler wires and the workpiece. Therefore, the present invention can be applied to a filler wire process at a low cost without using an expensive high-strength energy source such as a laser device. Further, the heating system for the filler wire process according to the present invention can heat the filler wire and the workpiece to a local high temperature as much as necessary for a desired process, thereby saving energy than other filler wire devices.

Description

TECHNICAL FIELD [0001] The present invention relates to a hybrid heating method and system for a filler wire process,

The present invention relates to a hybrid heating method and system for resistance heating of a filler wire and a workpiece at the same time as induction heating for application to a filler wire process.

The filler wire process is a process for achieving a desired purpose by continuously heating and melting a consumable metal wire (filler wire) while continuously supplying it. For example, workpieces can be welded by induction heating while feeding metal filler wires and melting the heated wire with another energy source. In addition, the surface of the workpiece can be reinforced, cladded, built up, brazed, or joined with a filler wire process.

US Patent Application Publication No. US 2014/0008354 A1, entitled METHOD AND SYSTEM FOR USING INDUCTION HEATING TO HEAT CONSUMABLE DURING HOT WIRE PROCESS, USING INDUCTION HEATING FOR HEATING CONSUMABLES DURING HOT WIRE PROCESS, Methods and systems for processes are disclosed.

The filler wire process disclosed in the present invention comprises heating a workpiece to form a molten puddle, inducing the filler wire to a predetermined temperature, and supplying the heated filler wire to the molten pool . A high intensity energy source such as a laser device is used to heat the workpiece to form a molten pool. Examples of high-strength energy sources include gas tungsten arc welding equipment (GTAW), gas metal arc welding equipment (GMAW), and submerged arc welding equipment (SAW). In addition, the peel wire process disclosed in the above patent document may additionally perform resistance heating by flowing an electric current between the induction heated filler wire and the workpiece. Since the workpiece has a molten pool formed by a high-strength energy source, only the filler wire is melted by resistance heating.

When the welding operation is performed using the process disclosed in the above-mentioned invention, the amount of total heat energy applied to the workpiece can be reduced, thereby preventing deformation of the workpiece. In addition, the welding speed can be increased, the frying of the molten metal during welding can be reduced, and the welding can be performed without shielding.

On the other hand, interest in metal 3D printers is increasing recently. This is because, by using a metal 3D printer, it is possible to mass-produce complicated mechanical parts such as a pump impeller and a turbine blade at low cost.

US Patent No. 8,827,684 B1 (a 3D printer and a prit head unit with a plurality of filaments, 3D PRINTER AND PRINTHEAD UNIT WITH MULTIPLE FILAMENTS) is provided with a plastic or metal wire (metal having a low melting point such as lead) Discloses a 3D printer for producing a three-dimensional shaped product by melting and extruding molten metal. In addition, US Patent Publication No. US 2014/0265037 A1 (entitled " INDUCTIVELY HEATED EXTRUDER HEATER ") discloses a method of induction heating a metal nozzle, supplying and melting a meltable material with a nozzle, A head for a 3D printer is disclosed.

The invention disclosed in the above patent documents relates to a three-dimensional printer of a fused deposition type (FDM) method in which a filler wire is melted and then extruded and laminated to produce a three-dimensional product. An FDM type three-dimensional printer using a filler wire can be regarded as a type of filler wire process in that the filler wire is continuously supplied while heating and melting to achieve a desired object. However, there is a difference from the invention disclosed in U.S. Publication No. US 2014/0008354 A1 in that the filler wire indirectly heats the filler wire supplied by using the heated print head without directly heating and melting the filler wire. There is also a difference in that the molten filler wire is passed through a nozzle to form a product by an extrusion process.

U.S. Published Patent Application No. 2014/0008354, METHOD AND SYSTEM OF USING INDUCTION HEATING TO HEAT CONSUMABLE DURING HOT WIRE PROCESS US Patent No. 8,827,684 B1, 3D PRINTER AND PRINTHEAD UNIT WITH MULTIPLE FILAMENTS US Published Patent US 2014/0265037 A1, INDUCTIVELY HEATED EXTRUDER HEATER

The filler wire process disclosed in US Patent Publication No. US 2014/0008354 requires a high-strength energy source for heating a workpiece to form a molten pool. High energy sources such as laser devices are expensive. Further, the control is complicated because the laser device and the filler wire induction heating device must be controlled in accordance with the filler wire process conditions. Further, when the filler wire is heated while passing through the inside of the induction heating coil, all of the filler wires positioned inside the induction heating coil are heated. Particularly, the portion located at the center of the coil is heated most by induction. Therefore, it is difficult to inductively heat only the end of the filler wire to a locally high temperature.

In addition, the filler wire process disclosed in the above-mentioned U.S. Patent No. 8,827,648 B1 and U.S. Patent No. US 2014/0265037 A1 is indirectly heated by the filler wire, which consumes a lot of energy. Further, since the melted filler wire is extruded through the nozzle after melting the filler wire, the nozzle may be clogged to cause failure or defect may occur when the nozzle is damaged. In addition, since the filler wire is indirectly heated by the printhead, there is a limitation in applying a filler wire process to a metal which is melted at high temperature, for example, steel or stainless steel. There is also a limit to heating the ends of the filler wire locally to a high temperature for a desired purpose.

There is a need for a heating system for the filler wire process that is simple to use and inexpensive. In particular, there is a need for a heating system that can be applied to a filler wire process without using expensive, high-strength energy sources such as laser devices.

There is also a need for a heating system for a filler wire process that can heat directly the filler wire to save energy and heat the filler wire as needed to the desired process locally at a high temperature. Particularly, there is a demand for a heating system capable of locally fusing and stacking both the filler wire and the workpiece simultaneously by locally heating the workpiece and the filler wire when the filler wire is melted and laminated on the workpiece. There is also a need for a heating system for a filler wire process that can completely block the contact of the molten filler wire and the workpiece with air.

It is an object of the present invention to provide a new hybrid heating method and system for a filler wire process that can meet such needs.

The hybrid heating system for a filler wire process according to the present invention comprises a filler wire supply device, an induction heating device for locally induction heating an end of the filler wire supplied from the filler wire supply device, Respectively. In addition, when the end of the filler wire heated by the induction heating device contacts the workpiece, the filler wire and the workpiece are heated so as to resistively heat the end of the contacted filler wire and the workpiece. And a resistance heating device for supplying electric current to the wire. The resistance heating apparatus includes a resistance heating power source unit for supplying current and a contact electrode arranged to be in contact with the filler wire.

The induction heating apparatus includes an induction heating power source unit for supplying a high frequency power source, an induction heating coil electrically connected to the high frequency power source unit, and a magnetic core inserted in the induction heating coil. The magnetic core is in the form of a hollow cylinder made of a magnetic material for providing a path of magnetic flux induced by the induction heating coil. The inlet for inserting the filler wire supplied from the filler wire supplying device and the inserted filler wire are discharged Lt; / RTI >

The induction heating coil can be formed by spirally winding the conductive wire (solenoid) or by winding the conductive plate round. An induction heating coil formed by winding a conductive material in a spiral or circular shape forms a hollow magnetic flux passage in the center portion. When a high frequency power source is applied to the induction heating coil, the center of the induction heating coil and the outside of the induction heating coil are connected by a closed curve, and a magnetic force line whose direction changes according to the frequency of the high frequency power source is formed. Conductors located inside a magnetic field formed by lines of magnetic force whose direction is changed by electromagnetic induction are heated.

The magnetic core provides a path to the magnetic flux induced by the induction heating coil and at the same time has an inlet through which the filler wire is fed to one end of the hollow and an outlet through which the filler wire is discharged. The magnetic core is formed of a magnetic material and provides a path of a magnetic field induced by the induction heating coil to prevent magnetic flux from passing through the filler wire inserted in the hollow of the core to prevent induction heating of the metal filler wire inside the core. The magnetic core may use a ferromagnetic material, but it is preferable that the magnetic material core is not heated to a high temperature, for example, a soft magnetic material core such as a cored core formed of an oxide such as a ferrite core or a metal powder. The outlet of the magnetic core is configured to allow the magnetic flux to pass through the filler wire discharged through the outlet to heat the end of the filler wire discharged from the hollow of the magnetic core.

In order to arrange the magnetic core inside the induction heating coil, an induction heating coil formed by winding a wire rod or an induction heating coil formed by winding a plate material to form a hollow can be used as the induction heating coil . The hollow induction heating coil concentrates the magnetic flux to increase the magnetic flux density at the position where the filler wire process is to be applied. The magnetic core inserted into the hollow of the induction heating coil blocks heating of the filler wire disposed inside the magnetic core and allows only the end of the filler wire exposed to the outside of the outlet of the magnetic core to be heated. Further, the workpiece disposed adjacent to the magnetic core is locally heated by the magnetic line of force emerging from the outlet side end of the magnetic core.

The induction heating power source unit may be configured to control the terminal temperature according to the cross-sectional area of the filler wire and the feed rate of the filler wire. It is also preferable that the resistance heating power source unit is configured to control the amount of current that flows through the filler wire in accordance with the cross-sectional area of the filler wire, the feed rate of the filler wire, and the temperature of the end portion of the filler wire.

In some embodiments, the length of the magnetic core inserted into the hollow of the induction heating coil is greater than the length of the induction heating coil so that the magnetic core can be more closely attached to the workpiece, So that it is slightly exposed from the end portion.

When the exit of the magnetic core is a simple planar shape cut at right angles to the center line of the cylindrical core, magnetic lines of force coming out of the core through the exit cut surface of the magnetic core or coming into the magnetic core from the outside are directed toward the centerline of the core It becomes a convex curved shape. Therefore, the filler wire discharged through the outlet hollow of the magnetic core and the magnetic force line passing through the magnetic core are linked to each other, so that only the end portion of the filler wire is heated. In some embodiments, the outlet of the magnetic core may be such that the inner diameter of the inner circumferential surface of the core hollow increases toward the end along the longitudinal direction to form a tapered surface on the inner circumferential surface of the outlet. When a magnetic line of force passes through a magnetic core through a tapered surface of an outlet, a magnetic line of force passes through a hollow of the outlet, . In some embodiments, the outlet of the magnetic core may extend radially inward. When the outlet extends to the inside and faces the outer circumferential surface of the filler wire, most of the magnetic force lines that go out through the outlet or enter the magnetic core from the outside are bridged with the ends of the peel wire exposed to the outside, .

In some embodiments, the inlet of the magnetic core may extend radially outward so that the filler wire supplied in the hollow through the inlet of the magnetic core and the magnetic force lines induced by the induction heating coil are not bridged, So that it is not heated. Further, in some embodiments, the diameter of the outer circumferential surface of the entrance of the magnetic core may be reduced toward the end along the length direction to form a tapered surface. When a magnetic line of force passes through a magnetic core through a tapered surface of an inlet, a magnetic line of force induced by the induction heating coil can pass through the magnetic core without being interlocked with the filler wire inserted in the hollow at the entrance of the magnetic core, The filler wire is not heated.

In some embodiments, the hybrid heating system for the filler wire process may further comprise shield gas supply means for preventing the end of the filler wire and the locally heated portion of the workpiece from contacting air when molten have. The shield gas supply means may supply the gas to the inlet of the magnetic core and discharge the gas to the outlet. The shield gas can be supplied by heating to a suitable temperature so that the molten filler wire and the workpiece are not cooled by induction heating and resistance heating.

The hybrid heating system for the filler wire process according to the present invention can be used to manufacture a complex three-dimensional product such as a pump impeller or a turbine blade. A rotating means for rotating the workpiece and a feeding means for feeding the magnetic core along the rotation axis of the workpiece when the filler wire is melted and laminated to produce an arbitrary three-dimensional shaped product. Further, it may further comprise cooling means for cooling the stacked product. It is apparent to those skilled in the art that the rotating means and the conveying means can be manufactured by known mechanical parts such as a motor, a linear guide, a ball screw, and an encoder. Further, the cooling means may be constituted by injecting cooling air around the stacked object through a nozzle or circulating cooling water into the circulation pipe.

According to another aspect of the present invention, a hybrid heating method for a filler wire process is provided. A hybrid heating method for a filler wire process according to the present invention includes the steps of supplying a filler wire to a hollow of a magnetic core provided inside an induction heating coil, disposing a workpiece close to the magnetic core, Applying a high frequency power to the induction heating coil to locally induce and heat an end of the filler wire discharged from the hollow of the magnetic core and a portion of the workpiece close to the magnetic core; And causing current to flow through a locally heated portion of the workpiece in contact with an end of the filler wire discharged from the hollow of the magnetic core to melt the end of the filler wire and the locally heated workpiece. The method may further include discharging the gas toward the workpiece by supplying gas into the hollow of the magnetic core so that the end portion of the filler wire and the locally heated portion of the workpiece do not contact the air.

The method may further include rotating the workpiece to produce a product having an arbitrary shape by melt-laminating the filler wires, and transferring the magnetic core through the filler wire along the rotation axis direction of the workpiece can do.

The heating system according to the present invention can locally heat the ends of the continuously supplied filler wires and the workpiece. Therefore, the present invention can be applied to a filler wire process at a low cost without using an expensive high-strength energy source such as a laser device.

Further, the heating system for the filler wire process according to the present invention can heat the filler wire and the workpiece to a local high temperature as much as necessary for a desired process, thereby saving energy than other filler wire devices.

Further, the heating system for the filler wire process according to the present invention can locally heat the workpiece and the filler wire, and at the same time, locally melt the filler wire to laminate the filler wire. Therefore, a three-dimensional product having a complicated shape can be produced from a metal having a high melting point. Particularly, a product having excellent strength can be produced as compared with a product produced by melting a metal powder by a laser and laminating it.

In addition, the heating system for the filler wire process according to the present invention can shield the molten filler wire and the workpiece from contact with the air by supplying the shield gas through the magnetic core, The quality can be improved.

1 is a schematic view of one embodiment of a heating system for a filler wire process in accordance with the present invention;
2 is a view illustrating a state in which a filler wire and a workpiece are heated and melted by a heating method for a filler wire process according to the present invention.
3 is a graph showing the non-linear relationship with the temperature of the metal
Fig. 4 is an explanatory diagram showing the temperature distribution of the filler wire in the case where the magnetic core is provided in the induction heating coil and in the case where the magnetic core is not provided;
5 is a schematic view of another embodiment of a heating system for a filler wire process according to the present invention
6 is a schematic view of another embodiment of a heating system for a filler wire process according to the present invention
FIG. 7 is a view showing another embodiment of the induction heating coil and the magnetic core used in the heating system according to the present invention
Figure 8 is a schematic view of the various embodiments of the magnetic core used in the heating system according to the present invention

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of one embodiment of a heating system 100 for a filler wire process in accordance with the present invention. The heating system of the present embodiment includes a filler wire feeder 120 and an end portion 132 of the filler wire 130 supplied from the filler wire feeder 120 and a workpiece 170 to which the filler wire is fed locally And an induction heating apparatus 140 for induction heating. And a resistive heating device 160 for heating resistance by flowing current to the filler wire 130 heated by the induction heating device 140 and the workpiece 170.

The filler wire 130 is made of metal. Any metal that can be induction-heated by a magnetic substance is possible. For example, iron and iron alloys, aluminum or aluminum alloys, copper and copper alloys processed into a wire shape can be used. The filler wire feeder can be manufactured in various forms and used in a conventional filler wire process A detailed description thereof will be omitted.

The induction heating apparatus 140 includes an induction heating power source unit 142 for supplying a high frequency power source, an induction heating coil 110 electrically connected to the induction heating power source unit 142, And includes a magnetic core 150 inserted therein. The magnetic core 150 is in the form of a hollow cylinder made of a magnetic material for providing a path of magnetic flux induced by the induction heating coil 110. The magnetic core 150 has an inlet 150a for inserting the filler wire 130 supplied from the filler wire supplying device 120 and an outlet 150b for discharging the inserting filler wire. The induction heating power source unit 142 is configured to be able to adjust the voltage, current level, waveform, and frequency to be applied according to the metal material component of the filler wire 130, the shape and diameter of the wire cross section, and the feed rate of the filler wire . In particular, the induction heating power source unit 142 is preferably configured to control the terminal temperature according to the cross-sectional area of the filler wire and the feed rate of the filler wire.

The induction heating coil 110 may be formed by spirally winding a conductive wire material (solenoid) or by winding a conductive plate material in a circular shape. The induction heating coil 110 formed by winding the conductive material in a spiral or circular shape has a hollow magnetic flux passage formed at the center thereof. When a high frequency power source is applied to the induction heating coil 110, the center of the induction heating coil 110 and the outside of the induction heating coil 110 are connected by a closed curve, and a magnetic force line whose direction changes according to the frequency of the high frequency power source is formed. Conductors located inside a magnetic field formed by lines of magnetic force whose direction is changed by electromagnetic induction are heated. Although not shown in the embodiment of FIG. 1, the induction heating coil 110 may be installed in a ceramic housing for insulation and insulation. The induction heating coil may also be configured to flow cooling water for the induction heating coil using a hollow tube.

The magnetic core 150 is inserted into the hollow interior of the induction heating coil 110. The magnetic core 150 inserted in the hollow of the induction heating coil 110 provides a path for the magnetic flux induced by the induction heating coil 110. The magnetic core 150 has an inlet 150a for inserting the filler wire 130 into the hollow one end and an outlet 150b for discharging the filler wire 130. The magnetic core 150 is formed of a magnetic material and provides a passage of magnetic flux induced by the induction heating coil 110 to prevent the magnetic flux from passing through the filler wire 130 inserted in the hollow of the magnetic core 150. Thus, the filler wire formed of metal is prevented from being induction-heated when passing through the inside of the core.

The magnetic core 150 may be made of a ferromagnetic material, but it is preferable that the soft magnetic material core such as a cored core formed of an oxide such as a ferrite core or a metal powder is used to induce heating of the wire filler to a high temperature desirable. The outlet 150b of the magnetic core 150 is configured to allow the magnetic flux to pass through the filler wire discharged through the outlet 150b to heat the end 152 of the filler wire discharged from the hollow of the magnetic core 150. [ The workpiece 170 made of metal disposed adjacent to the magnetic core 150 is locally induction-heated by a magnetic force line emerging from the end face on the side of the outlet 150b side of the magnetic core 150. [ As shown, the magnetic core 130 inserted in the hollow of the induction heating coil 110 is guided by the induction heating coil 110 so as to more effectively heat and melt only the end of the filler wire 130 discharged from the hollow of the magnetic core 150 It is preferable that the length of the heating coil 110 is longer than the length of the heating coil 110 and that the outlet 150b of the magnetic core 150 is disposed adjacent to and slightly exposed from one end of the induction heating coil 110.

The resistance heating apparatus 160 includes a resistance heating power supply unit 164 and a contact electrode 162 provided to contact the filler wire 130. The contact electrode 162 is configured such that when the filler wire is transported, contact is secured and no spark occurs. The resistance heating power supply unit 164 applies a voltage so that current flows through the filler wire 130 and the workpiece 170. The resistance heating power supply unit 164 may apply a low-voltage high-current power source, for example, a voltage of 6 to 14 volts, so that an arc is not generated at a portion where the end of the filler wire 130 contacts the workpiece. The power supplied from the resistance heating power supply unit 164 can be determined by the temperature of the end portion 132 of the filler wire 130 heated by the induction heating and the temperature of the heating portion 172 of the workpiece 170 have. Further, it can be set to a suitable value in accordance with the filler wire and the metal material component of the workpiece, the shape and diameter of the section of the filler wire, and the feeding speed of the filler wire. The resistance heating power supply unit 164 can be configured to supply a proper voltage and current according to the filler wire process. In particular, it is preferable that the resistance heating power supply unit 164 be configured to control the amount of current that flows through the filler wire in accordance with the cross-sectional area of the filler wire, the feed rate of the filler wire, and the temperature of the terminal portion of the filler wire.

The filler wire heating system 100 of the present embodiment can be configured to move the magnetic core 150 relative to the workpiece 170 or to move the workpiece relative to the magnetic core 150 during the filler wire process have. Although not shown, the filler wire heating system 100 of the present embodiment is provided separately with a drive means and a control device for moving a workpiece or a magnetic core.

Referring to FIG. 2, the filler wire and the workpiece are melted and coupled by the filler wire heating system of this embodiment. The filler wire 130 supplied by the filler wire feeder 120 is not heated by the magnetic core 150 when the filler wire 130 passes through the hollow interior of the magnetic core 150 . Therefore, only the end portion 132 of the filler wire 130 passing through the outlet 150b of the magnetic core 150 is induction-heated by the magnetic flux m entering and exiting from the magnetic core 150. [ A portion 172 of the workpiece 170 adjacent to the outlet 150b of the magnetic core 150 is also locally induction heated by the magnetic flux m exiting and entering the outlet of the magnetic core 150. [

Referring to Fig. 3, the merits of heating only the distal end of the filler wire to a high temperature will be described in more detail. In the graph of Fig. 3, the L2 curve is a temperature distribution curve for the longitudinal direction of the induction-heated filler wire disposed inside the induction heating coil when the magnetic core is not installed in the induction heating coil. When the length of the induction heating coil is a - b and the end of the filler wire disposed inside the induction heating coil protrudes by b - d length, the portion of the filler wire located at the center c distance of the induction heating coil is at the maximum temperature And heated. The exposed end portion (b-d portion) in the induction heating coil is cooled while passing through the center portion c, and becomes lower in temperature than the center portion. If the center temperature of the filler wire is heated to near the melting temperature T2 in order to raise the temperature of the terminal end of the filler wire, the melted center portion of the filler wire is broken and may fall off to the workpiece. Therefore, the filler wire can not be heated to a sufficiently high temperature by induction heating, and a separate energy supply device such as a laser is required to heat the end portion of the filler wire in contact with the workpiece object to a high temperature in a short time.

The L1 curve is a temperature distribution curve in the longitudinal direction of the induction-heated filler wire disposed inside the magnetic core when the magnetic core is disposed inside the induction heating coil. When the length of the magnetic core is equal to the length of the induction heating coil, the filler wire portion (a - b portion) disposed inside the magnetic core shields the magnetic flux by the magnetic core, so that the induction heating is not performed and the temperature is relatively low. However, the end portion (b-d) exposed in the magnetic core is inductively heated by the magnetic force lines passing through the outlet portion of the magnetic core, so that the temperature of the filler wire becomes highest. Further, even if the end portion (b-d) is heated near the melting temperature of the filler wire, there is no risk of falling off.

 When current i is supplied to the filler wire 130 from the resistance heating power supply unit 164 when the terminal of the filler wire and the workpiece are heated close to the melting temperature, the electric current flows between the filler wire 130 and the workpiece 170 . As shown in FIG. 4, the higher the temperature, the greater the resistivity of the metal conductor. Therefore, the end portion 132 (indicated by the dotted line B) of the filler wire 130 higher in temperature than the other portion is locally induction-heated and the workpiece 170 is induction-heated close to the end portion of the magnetic core 130 The electrical resistance becomes larger than that of the portion 172 (indicated by the dotted line A) that is not induction-heated (the portion inside the magnetic core 150 and the portion of the workpiece away from the magnetic core 150). Therefore, the induction heating portion B of the filler wire and the induction heating portion A of the workpiece 170 are resistively heated by the current i by the current i. In addition, the portion where the filler wire 130 and the workpiece 170 are in contact becomes more heated due to the contact resistance, and melting occurs first at the contact portion. That is, the molten portion B-1 is first formed at the end of the filler wire 130, and at the same time, the molten portion A-1 is formed at the contact portion of the workpiece to cause intermetallic bonding. At this time, when the workpiece 170 or the magnetic core 150 is transported at a proper speed, the fused portion B-1 of the filler wire 130 is laminated on the workpiece 170, and a filler wire process is performed.

The heating system according to the present invention can heat the filler wire and the workpiece at the same time by induction heating so as to locally increase the electrical resistance and increase the efficiency of the resistance heating by flowing a current through the metal having higher electrical resistance, And melting by heating. The present invention refers to a heating system having such heating characteristics as a hybrid heating system.

Figure 5 is a schematic view of another embodiment of a heating system for a filler wire process in accordance with the present invention. The embodiment shown in FIG. 5 is shown by emphasizing only the added portion by omitting the elements overlapping with the embodiment shown in FIG. The hybrid heating system shown in Fig. 5 further includes shield gas supply means for preventing the ends of the heated filler wires and the workpiece from coming into contact with air. The shield gas supply means includes a shield gas tank 184 and a heating device 182 for heating the gas discharged from the shield gas tank. And a nozzle 180 mounted on the inlet 150a of the magnetic core 150 for jetting the gas into the hollow of the magnetic core 150. [ The gas g heated by the heating device 182 and injected through the nozzle 180 is discharged to the outlet 150b of the magnetic core 150 and flows to the end of the filler wire 130 and the heated Thereby preventing the portion from coming into contact with the air. As shown in Fig. 5, when the hybrid heating system is utilized in the welding process, it is possible to prevent the metal, which has been consumed in the welding portion, from being oxidized by contact with air.

Figure 6 is a schematic diagram of another embodiment of a heating system for a filler wire process in accordance with the present invention. The embodiment shown in Fig. 6 shows an embodiment for manufacturing a complex shaped product such as an impeller or turbine of a pump using a hybrid heating system according to the present invention. The hybrid heating system of this embodiment includes a rotating means for rotating the bosses 300. The rotating means includes a rotating shaft 310 and a motor and a motor control device (not shown) connected to the rotating shaft. A boss 300 is mounted on the rotary shaft 310 and a conveying means for conveying the magnetic core 150 to which the filler wire is fed while rotating the maintenance 300 along the center line direction of the rotary shaft 310 is provided. When the spiral blade is manufactured on the outer circumferential surface of the boss 300, the magnetic core 150 is simultaneously moved along the center line direction of the rotation axis 310 while rotating the rotation axis 310, And is laminated on the outer circumferential surface of the boss 300. Further, it may further include a cooling means (not shown) for cooling the stacked blades to maintain their shape. It is apparent to those skilled in the art that the rotating means and the conveying means can be manufactured by known mechanical parts such as a motor, a linear guide, a ball screw, and an encoder. Further, the cooling means may be constituted by injecting cooling air around the stacked object through a nozzle or circulating cooling water into the circulation pipe.

Figure 7 is another embodiment of an induction heating coil and a magnetic core that can be used in a heating system according to the present invention. The induction heating coil 210 of the present embodiment is formed by winding a conductive plate material such as a copper plate so as to form a hollow, thereby forming an induction heating coil, and a magnetic core 250 is disposed therein. As shown in the figure, the induction heating coil 210 is formed with a hollow for the magnetic core 250 to be inserted into the central portion thereof by rounding the plate material. The lower portion of the induction heating coil 210 corresponding to the inlet side of the magnetic core 250 is formed in a conical shape so as to be close to the workpiece.

Figure 8 illustrates various embodiments of magnetic cores that may be used in a hybrid heating system in accordance with the present invention.

The embodiment shown in FIG. 8 (a) is configured to extend the entrance portion 150a of the magnetic core 150 radially outward to provide a path of the magnetic flux. The magnetic core 150 shown in FIG. 8 (b) has a tapered surface formed on the outer circumferential surface of the inlet portion 150a-1 so that the diameter of the outer circumferential surface decreases toward the distal end along the central axis. When the magnetic force lines come out of the tapered surface on the outer circumferential surface of the core 150 or when the magnetic force lines enter the tapered surface, the magnetic force lines tend to form a shortest path of the shortest path uniformly in the space, So that almost no magnetic lines of force are generated. 8 (c) is different from FIG. 8 (b) in that the hollow inner peripheral surface of the outlet 150b of the magnetic core 150 is formed with a tapered surface so that the diameter of the inner peripheral surface increases toward the distal end along the central axis. The magnetic force lines tend to form a shortest path of the shortest path uniformly in the space when the magnetic force lines come out from the tapered surface or the magnetic force lines come into the tapered surfaces on the inner peripheral surface of the core 150, (130). 8 (d) is different from FIG. 8 (b) in that a protruding portion is formed on the hollow inner peripheral surface of the outlet 150b of the magnetic core 150 toward the central axis. As shown in FIG. 8 (c), more magnetic lines of force are linked to the filler wires 130. The shapes of the entrance and exit portions of the magnetic core 150 shown in Fig. 8 can be selectively applied as required. The magnetic core 150 may use a ferromagnetic material, but it is preferable that the magnetic core 150 is not heated to a high temperature by using, for example, a soft magnetic material core such as a cored core formed of an oxide such as a ferrite core or a metal powder. Particularly, the compacting core is a compacted magnetic material adhered with an insulating bonding material, and is suitable for high frequencies. In addition, since the magnetic powder of the pinion core has a shape close to a sphere, the magnetic permeability is small with respect to a wide magnetic field because the magnetic force is large, but the value of the specific magnetic permeability does not change with respect to the magnetic field.

Hereinafter, a hybrid heating method for the filler wire process will be described. First, the filler wire is supplied to the hollow of the magnetic core provided inside the induction heating coil. The filler wire is composed of a metal material and a cross-sectional shape suitable for the process, and is supplied at a predetermined speed. Next, the end of the magnetic core from which the filler wire is discharged and the workpiece are arranged close to each other. Next, a high frequency power source is applied to the induction heating coil to inductively heat the end portion of the filler wire discharged from the hollow of the magnetic core and the portion of the workpiece close to the magnetic core locally first. And simultaneously supplying current to the filler wire to cause current to flow through the locally heated portion of the workpiece that contacts the end of the filler wire discharged from the hollow of the magnetic core, The object to be worked is secondarily heated by resistance heating. If necessary, the gas is supplied to the hollow of the magnetic core to discharge the gas toward the workpiece so that the end of the filler wire and the locally heated portion of the workpiece do not come into contact with the air. In addition, when a three-dimensional product having a complex shape such as a turbine or a pump impeller is manufactured, the magnetic core, from which the filler wire is discharged, is transferred along the rotational axis direction of the workpiece while rotating the workpiece.

It should be understood that the embodiments according to the present invention described above do not limit the present invention but are illustrative, and the motor according to the present invention can be modified into various forms. In addition to the embodiments described above, the present invention can be embodied by those skilled in the art without departing from the spirit and scope of the invention, for example, by constructing the core by winding wires or by using permanent magnets. The present invention may be embodied in various forms within the scope and equivalents of the claims.

110 induction heating coil
120 filler wire feeder
130 filler wire
140 Induction heating apparatus
160 resistance heating device
170 Workpiece

Claims (10)

A filler wire feeder,
An induction heating device for locally induction heating an end portion of the filler wire supplied from the filler wire feeding device and a workpiece to which the filler wire is fed,
And a resistive heating device for supplying current to the filler wire such that current flows through the workpiece in contact with the filler wire to resistively heat the end of the heated filler wire and the locally heated portion of the workpiece and,
The induction heating apparatus includes:
An induction heating high frequency power source unit,
An induction heating coil electrically connected to the induction heating high frequency power source unit,
A hollow cylinder shape inserted in the induction heating coil and made of a magnetic material for providing a path of a magnetic flux induced by the induction heating coil and having an inlet for inserting a filler wire supplied from the filler wire feeding device And a magnetic core having an outlet through which the inserted filler wire is discharged. The method according to claim 1,
Further comprising shield gas supply means for supplying gas to the inlet of the magnetic core and for supplying gas to the outlet so that the end portion of the filler wire and the locally heated portion of the workpiece are not in contact with air Hybrid Heating System for Filler Wire Process. The method according to claim 1,
Wherein the outlet of the magnetic core is exposed from one end of the induction heating coil. The method according to claim 1,
Wherein the resistance heating apparatus includes a resistance heating power supply unit and a contact electrode electrically connected to the resistance heating power supply unit and provided so as to be in contact with the filler wire,
Wherein the resistance heating power supply unit is configured to control an amount of current flowing in the filler wire in accordance with the cross-sectional area of the filler wire, the feed rate of the filler wire, and the temperature of the end of the filler wire. The method according to claim 1,
Wherein the induction heating high frequency power source unit is configured to control a terminal temperature according to a cross-sectional area of the filler wire and a feed rate of the filler wire. 5. The method according to any one of claims 1 to 4,
Wherein the induction heating coil is formed by spirally winding a conductive wire. 4. The method according to any one of claims 1 to 3,
Rotating means for rotating the workpiece,
Further comprising transfer means for transferring said magnetic core along the axis of rotation of said workpiece. Supplying a filler wire to the hollow of the magnetic core provided inside the induction heating coil,
Placing a workpiece proximate the magnetic core,
Applying a high frequency power to the induction heating coil to locally induce and heat an end of the filler wire discharged from the hollow of the magnetic core and a portion of the workpiece close to the magnetic core;
Applying current to the filler wire to cause current to flow through the locally heated portion of the workpiece that contacts the end of the filler wire discharged from the hollow of the magnetic core, A hybrid heating method for a filler wire process comprising melting an object. 9. The method of claim 8,
Further comprising the step of supplying gas to the hollow of the magnetic core and discharging gas toward the workpiece so that the end of the filler wire and the locally heated portion of the workpiece do not contact air, Heating method. 9. The method of claim 8,
Rotating the workpiece;
And transferring the magnetic core through which the filler wire passes, along the direction of the rotation axis of the workpiece.

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