JP6504184B2 - Resistance welding machine - Google Patents

Description

  The present invention relates to a resistance welder provided with a plate-like table electrode as a lower electrode.

  2. Description of the Related Art Conventionally, there is a table-type resistance welding machine in which a lower electrode (referred to as "table electrode") has a plate shape and an upper electrode has a gun shape (see, for example, Patent Document 1). The lower electrode is fixed on a pedestal of the welder main body, and the upper electrode is supported by an arm that can move vertically and horizontally right above the lower electrode. Place the object to be welded (a set of two steel plates stacked on top of one another) on the lower electrode, fill the welding tip (i.e. the welding point) with the tip of the upper electrode, and apply electricity while applying pressure in that state. Welding is performed. Copper is mainly used as a material of the upper electrode and the lower electrode.

JP, 2009-066628, A

  By the way, since the lower electrode used in the above-described table type resistance welding machine is bent little by little by the heat generated at the time of welding, polishing using sandpaper is performed periodically. This polishing is limited to the case where the deflection of the lower electrode is small to some extent, and when the degree thereof is increased, it is necessary to perform a full-scale polishing such as rotary polishing. Although it is necessary to remove the lower electrode from the pedestal in order to perform a full-scale polishing, by removing the lower electrode from the pedestal, warpage may occur throughout. Depending on the degree of warpage that has occurred, the amount of polishing is increased, and the life of the lower electrode is shortened. Since the lower electrode is formed as thin as possible for cost reduction, it is extremely important to minimize the polishing amount in order to prolong the life of the lower electrode. The lower electrode is a consumable like the electrode tip attached to the upper electrode, so there is a way to replace it, but if it is replaced it costs more, so it is necessary to extend the product life by polishing .

  The present invention has been made in view of such circumstances, and is capable of suppressing both deflection caused by heat generated during welding of a lower electrode called a table electrode and warping due to removal from a pedestal of a welding machine main body. The purpose is to provide a welding machine.

In the resistance welding machine of the present invention, a plate-shaped lower electrode on which a workpiece to be welded is placed, which is a plate assembly formed by overlapping at least two steel plates, and an arm movable vertically and horizontally above the lower electrode and an upper electrode of the gun-shaped carried by the said is placed on the lower electrode to the welding point of the welded object Ategai the tip portion of the upper electrode, by energizing while pressing in that state The resistance welding machine for welding, wherein the lower electrode is a nonmagnetic, conductive and thermally conductive first plate-like metal body, and a second plate metal body having higher rigidity than the first plate-like metal body . Ri adopted and a plate-like metal body the laminated structure together, they are arranged the first sheet metal side toward the upper electrode.

  According to the above configuration, since the lower electrode has a laminated structure in which the second plate-like body having high rigidity is superimposed on the first plate-like metal body, bending due to use of the lower electrode can be suppressed, and welding is also performed. Warpage due to removal from the frame of the machine body can also be suppressed. Therefore, the amount of polishing at the time of polishing the first plate-like metal body can be minimized, and the lifetime of the lower electrode can be prolonged.

  In addition, since the lower electrode has the second plate-shaped metal body, the distance between the first plate-shaped metal body and the polishing table becomes wider, so that the lower electrode can be easily fixed to the polishing table.

  In the above configuration, the second plate-like metal body further has magnetism as a physical property.

  According to the above configuration, since the second plate-like metal body has magnetism as a physical property, the lower electrode can be polished without using a fixture such as a clamp or a bolt or the like by configuring the polishing table with a magnet. It can be fixed to That is, the lower electrode can be easily fixed to the polishing table.

According to the present invention, it is possible to suppress the deflection due to the use of the lower electrode called a table electrode and the warping due to removal from the pedestal of the welding machine main body, so the polishing amount when polishing the first sheet metal body is minimized. Thus, the life of the lower electrode can be extended.
In addition, since the second plate-like metal body exhibits magnetism as a physical property, the lower electrode can be fixed to the polishing table without using a fixture such as a clamp or a bolt by configuring the polishing table with a magnet. Can.

A side view showing an appearance of a resistance welder according to an embodiment of the present invention The perspective view which shows the table electrode and mount frame of the resistance welding machine of FIG. A-A line sectional view of FIG. 2 The perspective view which shows a mode that the table electrode of the resistance welding machine of FIG. 1 was mounted on the polishing table.

Hereinafter, preferred embodiments for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is a side view showing the appearance of a resistance welder 1 according to an embodiment of the present invention. In the figure, a resistance welding machine 1 according to the present embodiment includes a cooling unit 10, a power supply unit 11, a support post 12, a support arm 13, a welding gun 14, conductive cables 15A and 15B, and a table electrode 16. , A gantry 17, an operation panel 18, and a welding transformer 19. The welding gun 14 corresponds to the upper electrode, and the table electrode 16 corresponds to the lower electrode.

  The cooling unit 10 supplies cooling water for cooling the welding gun 14, the conductive cables 15A and 15B, the support arm 13, the table electrode 16, the welding transformer 19, and other parts through which current flows. The cooling unit 10 always operates while the resistance welding machine 1 is powered on to circulate cooling water with the welding gun 14. The power supply unit 11 starts operation by the start-up operation on the operation panel 18. The power supply unit 11 rectifies and converts three-phase AC power supplied from a power receiving facility (not shown) into direct current, and outputs high frequency alternating current that is PWM (Pulse Width Modulation) controlled from the obtained direct current.

  The high frequency alternating current output from the power supply unit 11 is supplied to the welding transformer 19 built in on the front side of the gantry 17. The support post 12 is vertically erected in the vicinity of the cooling unit 10 and the power supply unit 11, and supports the support arm 13 so as to be horizontally rotatable. The support arm 13 has a substantially L shape including a horizontal arm portion 13A extending in the horizontal direction with respect to the support post 12, and a vertical arm portion 13B extending downward in the vertical direction from the tip portion of the horizontal arm portion 13A. , Hold the welding gun 14 at the tip portion.

  The welding gun 14 is pivotally held by the end portion of the vertical arm portion 13B of the support arm 13 so as to draw an arc in the vertical direction. A spring coil 13C is stretched between the base end of the welding gun 14 and the tip of the vertical arm 13B, and the contraction of the spring coil 13C causes the base end of the welding gun 14 to be vertically upward Lifted up. Further, the distal end portion of the welding gun 14 is pressurized in the direction toward the table electrode 16 by a cylinder 26 provided at the proximal end portion of the vertical arm portion 13B. A chain (not shown) is contained in the vertical arm portion 13B, and one end of the chain is connected to the cylinder, and the other end is connected to a power point portion (not shown) of the welding gun 14. The operation of the cylinder 26 in the direction in which the chain is pulled up causes the welding gun 14 to rotate, and its tip portion is in pressure contact with the table electrode 16. The pressure welding to the table electrode 16 by the welding gun 14 is performed just before the welding is started (ie, just before the welding current is supplied) and released after the welding is completed. The description of the structure for introducing air into the cylinder 26 will be omitted. A removable cap tip 25 is attached to the tip of the welding gun 14.

  One end of the conductive cable 15A is connected to the plus electrode (not shown) of the secondary side output end of the welding transformer 19, and the other end is connected to the welding gun 14. One end of the conductive cable 15 B is connected to the negative electrode (not shown) of the secondary side output end of the welding transformer 19, and the other end is connected to the table electrode 16. For the conductive cables 15A and 15B, a metal material such as copper excellent in conductivity and thermal conductivity is used.

  The table electrode 16 is a stack of two sheet metal bodies. FIG. 2 is a perspective view showing the table electrode 16 and the frame 17 of the resistance welding machine 1, and FIG. 3 is a cross-sectional view taken along the line A-A of FIG. As shown in FIGS. 2 and 3, the table electrode 16 is made of a first plate-like metal member 161 such as copper which is nonmagnetic and excellent in conductivity and thermal conductivity, and a second material which is excellent in rigidity such as iron. A laminated structure in which the plate-like metal body 162 is integrated is employed. The table electrode 16 is disposed on the gantry 17 so that the second plate-like metal body 162 is located on the side of the gantry 17 and the first plate-like metal body 161 is located on the upper surface side of the second plate-like metal body 162. Ru. Further, the fixation of the first plate-shaped metal body 161 and the second plate-shaped metal body 162 is performed by a plurality of bolts 50. The table electrode 16 and the frame 17 are also fixed by a plurality of bolts 50. A workpiece to be welded is placed on the table electrode 16. An object to be welded is a plate set made of a metal plate such as two steel plates as described above. The gantry 17 has a table drive mechanism that vertically moves the table electrode 16 up and down.

  Returning to FIG. 1, the operation panel 18 has a display (not shown) such as a liquid crystal panel and a touch panel (not shown) of a resistive film type or the like attached on the display surface of the display. Through the touch panel of the operation panel 18, setting of welding conditions (“material”, “plate thickness”, “current value”, “energization time”, “pressing force”) for the object to be welded is performed. The welding transformer 19 is a welding transformer for resistance welding, which the inventors of the present invention previously proposed in Japanese Patent Application Laid-Open Nos. 2012-210654 (patent 5491560) and 2013-179205 (patent 5220931), and large current is generated in a short time. Have the feature of being able to supply

  The resistance welding machine 1 according to the present embodiment is configured as described above, and in the table electrode 16 that is the lower electrode, in particular, the first plate-shaped metal body 161 such as copper is made of iron or the like having high rigidity. Since a laminated structure in which the second plate-like members 162 are stacked is used, bending due to use of the table electrode 16 (that is, bending due to heat generated during welding) and warpage due to removal from the gantry 17 can be suppressed. As a result, the amount of polishing when the first sheet metal body 161 is polished can be minimized, and the life of the table electrode 16 can be extended. In addition, since the table electrode 16 has the second plate-shaped metal body 162, the distance between the first plate-shaped metal body 161 and the polishing table 17 can be widened, so the table electrode 16 can be attached to the polishing table 17 It becomes easy to fix. That is, fixing using a fixing tool such as a clamp or a bolt (not shown) becomes easy.

  Usually, the table electrode 16 is formed as thin as possible in order to keep the cost low, so that it is difficult to obtain a clamp margin for fixing to the polishing table 17, and a fixture such as a clamp or a bolt (not shown) Fixing by is difficult. On the other hand, in the resistance welding machine 1 of the present invention, since the second plate-like metal body 162 is provided, a clamp margin is obtained, and fixation using a fixture such as a clamp or a bolt is easy. .

  FIG. 4 is a perspective view showing the table electrode 16 mounted on the polishing table 60. As shown in FIG. As shown in the figure, the polishing table 60 is composed of a plate-shaped top plate 61 having a thickness, and square-shaped legs 62 disposed at each of four corner portions of the top plate 61. The table electrode 16 is fixed to the polishing table 60 by a fixture such as the clamp described above or a plurality of bolts. As described above, since the table electrode 16 has a laminated structure in which the second plate-like body 162 having high rigidity such as iron is superimposed on the first plate-like metal body 161 such as copper, it is almost warped. Can be placed on the polishing table 60.

  In addition to fixing the table electrode 16 to the polishing table 60 with a fixture such as a clamp or a plurality of bolts, all or part of the top plate 61 of the polishing table 60 is made of a magnet and a second plate By forming the metal body 162 of a magnetic material, it can be fixed to the polishing table 60 without using a fixture such as a clamp or a bolt. Since iron has magnetism as a physical property, by using an iron material for the second plate-like metal body 162, it can be fixed to the polishing table 60 extremely easily. Needless to say, when the second sheet metal member 162 is made of a magnetic material, rigidity is also required at the same time.

  As described above, according to the resistance welder 1 of the present embodiment, the table electrode 16 is made of iron or the like in the first plate-like metal body 161 which is nonmagnetic and is excellent in conductivity and thermal conductivity such as copper. Since a laminated structure in which the second plate-like metal bodies 162 excellent in rigidity are stacked is used, it is possible to suppress the bending due to the use of the table electrode 16 and the warpage due to removal from the gantry 17. Therefore, the amount of polishing when the first sheet metal body 161 is polished can be minimized, and the life of the table electrode 16 can be extended.

  In addition, since the distance between the first plate-shaped metal body 161 and the polishing table 60 can be increased because the table electrode 16 includes the second plate-shaped metal body 162, the table electrode 16 can be fixed to the polishing table 60. It will be easier.

Moreover, while using the metal material which has magnetism for the 2nd plate-like metal body 162, by comprising whole or one part of the top plate 61 of the grinding stand 60 with a magnet, fixtures, such as clamps, bolts, etc. are used. Thus, the table electrode 16 can be fixed to the polishing table 60. That is, the table electrode 16 can be easily fixed to the polishing table 60.

  Although the present invention has been described with reference to particular embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

  The present invention has the effect of suppressing deflection caused by heat generated during welding of the lower electrode called table electrode and warping due to removal from the pedestal of the welder main body, and the plate electrode having a plate-shaped table electrode as the lower electrode. It is suitable for the equipped resistance welding machine.

DESCRIPTION OF SYMBOLS 1 Resistance welding machine 10 Cooling unit 11 Power supply unit 12 Support post 13 Support arm 14 Welding gun 15A, 15B Conducting cable 16 Table electrode 17 Mounting base 18 Operation panel 19 Welding transformer 25 Cap tip 26 Cylinder 50 bolt 60 Polishing stand 61 Top plate 62 legs 161 first sheet metal body 16 2 second sheet metal body

Claims (1)

A gun-shaped shape supported by a plate-shaped lower electrode on which a workpiece to be welded is placed, which is a plate assembly formed by overlapping at least two steel plates, and an arm movable vertically and horizontally right above the lower electrode An upper electrode, wherein a front end portion of the upper electrode is filled at a welding point of the object to be welded placed on the lower electrode, and welding is performed by applying electricity while applying pressure in that state; ,
The lower electrode is
A nonmagnetic, conductive and thermally conductive first plate-like metal body and a second plate-like metal body having higher rigidity and magnetism than the first plate-like metal body are integrated. and Ri adopted a layered structure, it is disposed the first sheet metal side toward the upper electrode,
Resistance welder.

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