JP3048306U - Welding electrode - Google Patents

Abstract

(57) [Problem] To provide a welding electrode capable of reliably preventing a seat nut from being welded upside down to a plate-like work. SOLUTION: A positioned nut 11 and a plate-like work 1 are provided.
0 is passed through the upper electrode 1 and the lower electrode 2, and the two are welded by resistance heating.
The energization detection ring 5 is provided on the outer peripheral surface of the diameter-reduced cylindrical portion 3 via an electrical insulating ring 4 so as to be vertically movable. When the transmitter 7 is connected and the nut 11 is set upside down, the nut seat 12 having a diameter larger than the outer diameter of the reduced-diameter cylindrical portion 3 comes into contact with the energization detection ring 5 and a signal is output. According to the welding stop signal issued from the transmitter 7, the upper and lower electrodes are not energized.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a welding electrode capable of preventing a seat nut from being welded upside down to a plate-like work.

[0002]

[Prior art]

 For example, in a sheet metal of an automobile or a casing of various devices, a seat nut for attaching another member to a plate-shaped work is welded. That is, a pilot hole is made in a plate-like work, and a nut hole is aligned with the pilot hole, and then the two are welded. In this case, generally, an upper and lower electrode type welding machine is widely used, and a plate-like work and a seat nut are automatically supplied to perform welding automatically.

However, in the conventional example, there is a problem in that even if the seat nut is supplied upside down, the electrode tip of the welding machine is welded as it is, because the electrode tip is not devised. Therefore, as a welding electrode capable of preventing such an illegal welding of a nut, an illegally supplied nut is welded to a work side at the time of welding as disclosed in Japanese Utility Model Publication No. 60-37167. There is also proposed an electrode which is welded to an electrode or an auxiliary electrode attached to the electrode without using the electrode. However, in this case, although incorrect welding is eliminated, when the nut is welded to the electrode side, the electrode needs to be replaced, so that the welding operation has to be interrupted and the workability is poor.

[0004]

[Problems to be solved by the invention]

 The present invention solves the conventional problems as described above, and can reliably prevent the seat nut from being welded upside down to the plate-like workpiece, and the seat nut is supplied incorrectly. It has been completed with the objective of providing a welding electrode that enables welding to be performed continuously by making it impossible to weld with a plate-like work when it is performed, and also by preventing a nut from being welded to the electrode side. It is a thing.

[0005]

[Means for Solving the Problems]

 The welding electrode of the present invention made in order to solve the above-mentioned problem is configured such that a nut hole is conducted to a nut lower hole of a plate-like work to position the nut on the surface of the plate-like work, and the upper electrode is connected to the upper electrode. In the welding electrode in which the lower electrode is energized and the nut is welded to the plate-like work by resistance heating, a reduced-diameter cylindrical portion that contacts the upper end of the nut during welding is formed below the upper electrode. In the case where the nut is set upside down, an energization detection ring is provided on the outer peripheral surface of the reduced-diameter cylindrical portion via an electrical insulating ring so as to be vertically movable, and a signal transmitter is connected to the energization detection ring. The seat of the nut having a diameter larger than the outer diameter of the reduced-diameter cylindrical portion is in contact with the conduction detection ring, so that the upper and lower electrodes are not energized in accordance with a welding stop signal issued from a signal transmitter. Also It is.

[0006]

[Embodiment of the invention]

 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The drawing shows a welding electrode in which a nut 11 is welded to a plate-like work 10 by resistance heating, wherein 1 is an upper electrode, 2 is a lower electrode, and a nut of the plate-like work 10 is shown. The point that the nut hole 11a is conducted to the lower hole 10a to position the nut 11 on the surface of the plate-like work 10, and that the upper electrode 1 and the lower electrode 2 are energized and welded to each other. It is basically the same as the welding electrode.

In the present invention, a reduced-diameter cylindrical portion 3 that contacts the upper end of the nut 11 during welding is formed below the upper electrode 1, and an outer peripheral surface of the reduced-diameter cylindrical portion 3 is provided on the outer peripheral surface of the reduced-diameter cylindrical portion 3. An energization detection ring 5 is provided to be vertically movable via an insulating ring 4, and a signal transmitter 7 is connected to the energization detection ring 5. A nut 11 automatically supplied by a robot or the like is set upside down. In this case, the nut seat 12 having a diameter larger than the outer diameter of the diameter-reduced cylindrical portion 3 comes into contact with the conduction detection ring 5, and a gap between the upper and lower electrodes is made according to a welding stop signal issued from the signal transmitter 7. It is configured not to energize.

As shown in FIGS. 2 and 3, a vertically long guide groove 5 a is formed in the conduction detection ring 5, and the guide groove 5 a is used to determine the position of the electric insulating ring 4. When the nut 11 is set upside down, the nut seat 12 comes into contact with the energization detection ring 5 and follows the guide groove 5a. Is pushed up until it comes into contact with the upper electrode 1. When the energization detection ring 5 comes into contact with the upper electrode 1 and energizes, the signal transmitter 7 is configured to generate a welding stop signal. As a result, control is performed so that the upper and lower electrodes are not energized. Things.

In the illustrated embodiment, the electrical insulating ring 4 is detachably attached to the upper electrode 1 by a pair of positioning bolts 6 from the peripheral surface side, and is used for maintenance such as repair and correction. It is configured so that work and replacement work can be easily performed. The positioning bolt 6 may be a single connecting bolt or three or more bolts. In the illustrated case, the electrically insulating ring 4 is mounted so that the distal end of the reduced diameter cylindrical portion 3 projects slightly ahead, and when the nut 11 is set normally, the electrical insulating ring 4 is connected to the reduced diameter cylindrical portion 3. When the nut 11 is set upside down, the seat 12 of the nut comes into contact with the electric insulating ring 4 and the gap between the tip of the reduced-diameter tube 3 and the bottom 13 of the nut is established. A gap is formed so that no current flows between the upper and lower electrodes.

[0010] With such a configuration, the nut 11 is positioned on the surface of the plate-like work 10 by conducting the nut hole 11a to the nut lower hole 10a of the plate-like work 10, and the upper electrode 1 This is basically the same as the conventional welding electrode of this type in that the current is supplied to the lower electrode 2 and the welding is performed. When the nut 11 is supplied normally, as shown in FIG. Then, the nut 11 comes into contact with the lower end surface of the reduced-diameter cylindrical portion 3 of the upper electrode 1 to conduct electricity between the upper and lower electrodes to perform the welding process. Further, since the electric insulating ring 4 is mounted so that the distal end portion of the reduced diameter cylindrical portion 3 projects slightly ahead, the nut 11 is reliably prevented from coming into contact with the electric insulating ring 4 in a normal state. At the same time, the welding process is carried out promptly by securely contacting the upper surface of the nut 11.

In the unlikely event that the nut 11 is supplied upside down, as shown in FIG. 4, the nut seat 12 has a diameter larger than the outer diameter of the reduced diameter cylindrical portion 3 of the upper electrode 1. Contact the conduction detection ring 5 and push it upward along the guide groove 5a. When the energization detecting ring 5 comes into contact with the upper electrode 1, a welding stop signal is generated from the signal transmitter 7, and the upper and lower electrodes are controlled so as not to energize. As a result, it is not necessary to replace the electrode as in the conventional case where the supplied nut is welded to the electrode or the auxiliary electrode attached to the electrode, and the welding operation is efficiently performed without interruption. The welding operation can be continued.

[0012]

[Effect of the invention]

 As is clear from the above description, the present invention can reliably prevent the seat nut from being welded upside down to the plate-shaped workpiece, and can prevent the seat nut from being incorrectly supplied when the seat nut is incorrectly supplied. The welding work can be performed continuously by making it impossible to weld to the workpiece and preventing the nut from being welded to the electrode side. Therefore, the present invention has an extremely large practical value as a welding electrode that has eliminated the conventional problems.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an upper electrode.

FIG. 3 is a side view showing an upper electrode.

FIG. 4 is a sectional view showing a case where the nut is supplied upside down.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper electrode 2 Lower electrode 3 Reduced diameter cylindrical part 4 Electrical insulating ring 5 Electricity detection ring 5a Guide groove 6 Positioning bolt 7 Signal transmitter 10 Plate work 10a Nut lower hole 11 Nut 11a Nut hole 12 Nut seat

Claims (3)

[Utility model registration claims] 1. A nut hole (11a) is conducted to a nut pilot hole (10a) of a plate-like work (10) to position the nut (11) on the surface of the plate-like work (10), and the upper electrode ( 1) and lower electrode
(2) The welding electrode which is energized by (2) and welds the nut (11) to the plate-like work (10) by resistance heating,
Under the upper electrode (1), a reduced-diameter cylindrical portion (3) that is in contact with the upper end of the nut (11) during welding is formed, and an electric insulating ring (4) is formed on the outer peripheral surface of the reduced-diameter cylindrical portion (3). ) Through which the energization detection ring (5) can be freely moved up and down.When the signal transmitter (7) is connected to this energization detection ring (5) and the nut (11) is set upside down, The nut seat (12) having a diameter larger than the outer diameter of the reduced diameter cylindrical portion (3) comes into contact with the conduction detection ring (5), and the upper and lower electrodes according to a welding stop signal issued from the signal transmitter (7). An electrode for welding, wherein current is not supplied between the electrodes. 2. A longitudinal guide groove (5) is provided in the energization detection ring (5).
The welding electrode according to claim 1, wherein a) is formed, and the guide groove (5a) is configured to move up and down by being engaged with a positioning bolt (6) of an electrically insulating ring (4). 3. The welding electrode according to claim 1, wherein the electrically insulating ring is detachably attached to the upper electrode by a positioning bolt from the peripheral surface side. .