JP3852823B2 - Electromagnetic welding machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic welding machine for welding a thin metal plate by electromagnetic force, and more particularly to a current-carrying portion of a welding current.
[0002]
[Prior art]
Aluminum is increasingly used to meet the demand for lighter products. When joining metal sheets, spot welding or seam welding is generally performed using an electric resistance welder, but welding with an aluminum electric resistance welder has been difficult. That is, since aluminum has high thermal conductivity and electrical conductivity regardless of its melting temperature, it is necessary to flow a large current during welding, and there is a problem that molten aluminum is likely to be deposited on the electrode. Further, in the case of seam welding, the current is diverted to the already welded portion, making it difficult to weld adjacent portions that should be subsequently welded.
[0003]
In order to solve such a problem, one of the inventors of the present application instantaneously applies a large current to a flat coil, and instantaneously welds the thin metal plate by electromagnetic force, such as Japanese Patent Laid-Open No. 11-192562. Considering the electromagnetic welding method, the practical application is being promoted. In this method of electromagnetic welding of thin metal plates disclosed in Japanese Patent Laid-Open No. 11-192562, the thin metal plates to be welded are stacked and placed between flat plate coils, and a large current is passed through the flat plate coils for welding. At least one of the upper and lower sides of the flat coil is provided with a concentrating portion through which current flows. The thin metal plate, which is an object to be welded sandwiched between the upper and lower flat coils, faces the concentrating portion. Welded in position. In order to flow a large current through the flat coil, a capacitor is charged by a DC high voltage power supply device, and the electric charge stored in the capacitor is instantaneously discharged to the flat coil through a switch.
[0004]
The voltage of the DC high-voltage power supply device required here is, for example, 5 to 15 kV, the capacitance of the capacitor is 50 to 200 μF, the peak value of the discharge current thereby reaches 100 kA or more, and the discharge time is 100 μsec or less. In order to embody this welding method as an electromagnetic welding machine, in order to flow a large current in a short time, the inductance of the flat coil circuit is made small, and attachment and removal of the work piece can be easily performed. It is necessary to. In addition, even if instantaneous, a large current flows and a large force is applied to the flat coil, so that the flat coil and the support member must be able to withstand this. Furthermore, since the concentrated portion of the flat coil to which a large force is applied is deformed and damaged, it must be easily replaced. It is difficult to satisfy all these conditions, and it has not yet been realized as a practical electromagnetic welding machine.
[0005]
[Problems to be solved by the invention]
The present invention solves the above problems, makes the upper plate coil movable, makes it easy to mount and take out the workpiece, and makes it easy to replace the upper and lower plate coils for practical use. It was made in order to provide the electromagnetic welding machine which can be provided.
[0006]
[Means for Solving the Problems]
The above problem is that the movable frame having the upper plate coil fixed to the machine base in which the lower plate coil is insulated and fixed by an insulating material is pivotally mounted so that the lower plate coil and the upper plate coil can be opened and closed. The electromagnetic wave according to the present invention is characterized in that a concentrated portion in which current flows is provided so that the concentrated portion of the lower flat coil and the concentrated portion of the upper flat coil face each other with the movable frame closed. Can be solved by a welding machine.
Also, one discharge electrode constituting the discharge gap switch is attached to the movable frame, and one end of the upper plate coil is connected to the discharge electrode, and the concentrated portion of the lower plate coil and the upper plate coil has enhanced hardness. Consists of copper alloy, except for the lower flat coil and the concentrated part of the upper flat coil are made of copper alloy with high electrical conductivity, or a copper alloy with high hardness and tensile strength is placed in the center. Further, it can be realized by forming a concentrated portion of the lower flat coil and the upper flat coil with a material in which a copper alloy or an aluminum alloy having a high electrical conductivity is arranged around.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the electromagnetic welding machine of the present invention will be specifically described with reference to the drawings.
In the embodiment shown in FIGS. 1 and 2, a lower flat coil 2 is insulated and fixed by an insulating material 3 on a box-type machine base 1. A movable frame 6 is provided on the upper surface of the lower planar coil 2 with the upper planar coil 4 fixed by an insulating material 5, and a pivoting member 7 is provided on the rear side of the machine base 1 on the rear side of the movable frame 6. It is pivotally attached and the front part can be opened and closed. The opening angle of the movable frame 6 is preferably 90 to 120 degrees, and the upper plate coil 4 is not exposed when the movable frame 6 is closed. A capacitor 8 is provided on the rear side of the machine base 1, and the ground side electrode of the capacitor 8 is connected to the rear end of the lower flat coil 2 by a connection plate 9. As shown in FIG. 3, the lower flat coil 2 is provided with a concentrated portion 10 in the middle, and the upper flat coil 4 is similarly provided with a concentrated portion 11. The concentrated portion 10 of the lower flat coil 2 and the concentrated portion 11 of the upper flat coil 4 are arranged to face each other when the movable frame 6 is closed on the lower flat coil 2.
[0008]
Further, the end surfaces of the front ends of the lower flat coil 2 and the upper flat coil 4 are made to be flush with each other when the movable frame 6 is closed, and the rear end of the upper flat coil 4 is fixed to the movable frame 6. It is connected to one discharge electrode 12 constituting the gap switch. At the rear of the machine base 1, the other discharge electrode 13 that constitutes the discharge gap switch facing the discharge electrode 12 when the movable frame 6 is closed on the lower flat plate coil 2 is insulated from the machine base 1 and attached. The discharge electrode 13 is connected to the other electrode of the capacitor 8. Furthermore, the discharge electrode 12 is provided with a trigger electrode (not shown).
[0009]
A contact 14 is attached to the front of the machine base 1 by being insulated from the machine base 1 by a moving mechanism 15 so as to be movable back and forth. The contactor 14 is moved when the movable frame 6 is closed on the lower flat plate coil 2 and is brought into contact with the end surfaces of the front ends of the lower flat plate coil 2 and the upper flat plate coil 4 that are in the same plane. It is for making it happen. It is preferable to apply silver plating or gold plating to the surface of the contact 14 in contact with the front end faces of the lower flat coil 2 and the upper flat coil 4, thereby reducing contact resistance. Reference numeral 16 denotes a handle for gripping when the movable frame 6 is opened and closed, but the movable frame 6 can be opened and closed and the contactor 14 can be moved back and forth by an air cylinder, an electric motor or the like. In the above configuration, a circuit is formed by the discharge electrode 12 and the discharge electrode 13 at the rear end of the upper flat coil 4, so that the rear end of the upper flat coil 4 that opens and closes and the other pole of the capacitor 8 are connected. There is an advantage that there is no need to connect directly. The material of the discharge electrodes 12 and 13 is preferably a copper tungsten alloy, a silver tungsten alloy or the like from the viewpoint of durability. When the replacement is required, the movable frame 6 is exposed in an open state so that it can be easily attached and detached. Is possible.
[0010]
FIG. 3 shows an appearance of the lower flat coil 2, and FIG. 4 shows an example of a cross-sectional configuration of the concentrated portions 10, 11 of the lower flat coil 2 and the upper flat coil 4. It consists of part 18. The core portion 17 is made of a material such as copper alloy, aluminum alloy, iron alloy, or titanium having high hardness and tensile strength, and the exterior portion 18 is made of a material such as copper alloy, aluminum alloy, or silver alloy having high electrical conductivity. . What is shown in A is that the entire circumference of the core portion 17 is covered with the exterior portion 18 and is excellent in conductivity, and what is shown in B is that the entire circumference of the core portion 17 is covered with the exterior portion 18, but the exterior portion 18. The part shown in C is easy to manufacture. The core part 17 is partly exposed from the exterior part 18 and has excellent strength. The concentrated portion 10 configured in this way is joined by means of brazing or the like at the joint portion 19 of the lower flat coil 2 shown in FIG. 2, and the concentrated portion 11 is also joined to the upper flat coil 4 in the same manner. To do.
[0011]
When the movable frame 6 of the electromagnetic welding machine configured as described above is opened, a portion to be welded is placed on the concentrated portion 9 of the lower flat coil 2, and the movable frame 6 is closed, welding of the workpiece is performed. The portion that should be sandwiched between the concentrated portion 9 and the concentrated portion 11 is. At this time, an insulating sheet is sandwiched between the work piece and the concentrated portions 9 and 11. The contact 15 is moved to conduct between the front ends of the lower flat coil 2 and the upper flat coil 4, and the capacitor 8 is charged by a DC high-voltage power supply device (not shown). When charging is stopped after the capacitor 8 is charged and a voltage is applied to the trigger electrode from a control device (not shown), a discharge starts between the discharge electrodes 12 and 13 and the discharge gap switch is turned on. 13, discharge electrode 12, upper plate coil 4, contact 15, lower plate coil 2, discharge through the circuit of connection plate 9, and the work piece sandwiched between concentrated portions 10 and 11 is welded. The
[0012]
FIG. 5 shows another configuration of the lower flat coil 2 and the upper flat coil 4. Discharge electrodes 20 and 21 constituting a discharge gap switch are provided at the front ends of the lower flat coil 2 and the upper flat coil 4, respectively. The rear end of the lower flat coil 2 is connected to the ground side pole of the capacitor 8 as shown in FIG. 1, and the rear side of the upper flat coil 4 is connected to the other pole of the capacitor 8. Since the flat coil 4 is fixed to the movable frame 6 and opens and closes, the flat coil 4 can be dissociated when the movable frame 6 is opened. A trigger electrode 22 is attached to the discharge electrode 20 of the lower flat coil 2. Although it is possible to attach the trigger electrode 22 to the discharge electrode 21 of the upper flat coil 4, it is preferable to attach the trigger electrode 22 to the discharge electrode 20 of the lower flat coil 2 that does not open and close from the viewpoint of connecting the electric wire to the trigger electrode 22. . It is the same as that shown in FIG. 3 to join the concentrated portions 10 and 11 at the joint portion 19 by means such as brazing. When the lower plate-like coil 2 and the upper plate-like coil 4 are as shown in FIG. 5, there is an advantage that it is not necessary to provide the contact 15 and therefore it is not necessary to operate the contact 15. The material of the discharge electrodes 20 and 21 is preferably a copper tungsten alloy, a silver tungsten alloy or the like, as in the case shown in FIG. 2, but the lower plate coil 2 and the upper plate coil 4 are joined. It can be replaced by brazing or screwing.
[0013]
Similarly, the lower plate-like coil 2 and the upper plate-like coil 4 configured as shown in FIG. 5 should open the movable frame 6 and weld the work piece onto the concentrated portion 10 of the lower plate-like coil 2. When the capacitor 8 is charged by a DC high-voltage power supply device (not shown), charging is stopped after the capacitor 8 is charged, and a voltage is applied to the trigger electrode 22 from a control device (not shown), The discharge starts and the discharge gap switch becomes conductive, and the electric charge of the capacitor is discharged through the circuit of the upper plate coil 4, the discharge electrode 21, the discharge electrode 20, and the lower plate coil 2, and between the concentrated portions 10 and 11. The object to be welded is welded.
[0014]
In the above embodiment, the pivot 7 is provided at the rear part of the machine base 1 and the movable frame 6 is pivoted so that it can be opened and closed back and forth. However, this is provided on the side of the machine base 1. Needless to say, the movable frame 6 may be pivotally attached and opened and closed in the lateral direction.
[0015]
【The invention's effect】
According to the present invention described above, since the movable frame is opened and closed, the concentrated portions of the upper and lower flat coils can be accurately aligned, and the upper and lower flat coils and the discharge electrodes can be easily replaced. There is. In addition, this makes it easy to mount and take out the workpiece, and it contributes to the industry as an electromagnetic welder that can be put to practical use.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of the present invention.
FIG. 2 is a plan view showing an embodiment of the present invention.
FIGS. 3A and 3B are a plan view and a side view of a lower plate coil according to the embodiment of the present invention. FIGS.
FIG. 4 is a cross-sectional view of concentrated portions of a lower plate coil and an upper plate coil in the embodiment of the present invention.
FIGS. 5A and 5B are a side view, a plan view, and a bottom view of an upper plate coil and a lower plate coil according to another embodiment of the present invention. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Machine stand 2 Lower flat coil 3 Insulation material 4 Upper flat coil 5 Insulation material 6 Movable frame 7 Pivoting member 8 Capacitor 9 Connection board 10 Concentration part 11 Concentration part 12 Discharge electrode 13 Discharge electrode 14 Contact 15 Moving mechanism 16 Handle 17 Core part 18 Exterior part 19 Joint part 20 Discharge electrode 21 Discharge electrode 22 Trigger electrode

Claims (4)

A movable frame with the upper plate coil fixed thereto is pivotally attached to a machine base in which the lower plate coil is insulated and fixed by an insulating material, and current is concentrated on the lower plate coil and the upper plate coil respectively. An electromagnetic welding machine characterized in that a concentrating portion that flows is provided so that the concentrating portion of the lower flat coil and the concentrating portion of the upper flat coil face each other with the movable frame closed. 2. The electromagnetic welding machine according to claim 1, wherein one discharge electrode constituting a discharge gap switch is attached to the movable frame, and one end of an upper flat coil is connected to the discharge electrode. Concentrated parts of lower flat coil and upper flat coil are made of copper alloy with enhanced hardness, and parts except concentrated parts of lower flat coil and upper flat coil are made of copper alloy with high electrical conductivity The electromagnetic welding machine according to claim 1 or 2, wherein Concentrated part of lower plate coil and upper plate coil is made of material with copper alloy with high hardness and tensile strength in the center and copper alloy or aluminum alloy with high electrical conductivity around. The electromagnetic welding machine according to claim 1 or 2 .

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