JPH0357347Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a nut welding machine, and particularly to a stationary nut welding machine for welding a nut to a workpiece by spot welding.

[Conventional technology]

A stationary nut welding machine for spot welding a nut to a member to be welded has conventionally been constructed as shown in FIG. That is, a pressure cylinder 2 is fixed to the upper part of the stand 1 of the welding machine, and a lower electrode 3 is fixed to the lower part thereof, and the upper electrode 5 is placed on the rod 4 of the pressure cylinder 2 at a position facing the lower electrode 3. installed. The member to be welded 6 is positioned and mounted by inserting a hole formed at a position where a nut is to be welded into a pilot pin 7 of the lower electrode 3.

On the other hand, nuts (not shown) are sent from a nut feeder 8 attached to the stand 1 to a nut supply cylinder 10 via a nut supply hose 9, and are supplied to the pilot pin 7 by the operation of the nut supply cylinder 10. Then, the rod 4 is lowered by the operation of the pressurizing cylinder 2, and the upper electrode 5 presses the nut and the member to be welded 6 against the lower electrode 3 and conducts the welding.

This method is called a straight type, and is configured so that the upper electrode is largely released in the opposite direction to the pressing direction in order to avoid interference between the nut supply cylinder 10 and the nut and the upper electrode 5 during nut supply.

FIG. 6 shows another conventional nut welding machine, which is called a base type. In this method, a pilot pin 7 is provided on the upper electrode 5, and the upper surface of the member to be welded 6 is attached to the upper electrode 5 and welded.

Conventional proposals regarding moving means for the welding gun of this type of welding machine include a two-joint arm structure disclosed in Japanese Patent Application Laid-Open No. 112182/1982,
41906, which uses a pair of toggle mechanisms and a link mechanism to perform pressure welding at the dead center position, and unidirectional shift and vertical welding, which is disclosed in Utility Model Application Publication No. 58-102276. There are known devices that allow for directional rotation.

[Problem that the invention attempts to solve]

Among the above-mentioned conventional nut welding machines, the straight type is used when the welded member 6 has a U-shaped cross section.
If the opening size is small, there is a problem in that the upper electrode 5 cannot be inserted into the opening of the member to be welded 6, making welding impossible.

Furthermore, although the base type has fewer restrictions on the opening size of the workpiece 6, it has problems in that it is inferior to the straight type in terms of workability, quality, equipment performance, work safety, etc. Further, the proposals in the above-mentioned publications all have restrictions on the opening dimensions of the welded members, and have the problem of not being able to accommodate welded members of various shapes.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a nut welding machine that can expand the range of shapes of weldable members that can be welded.

[Means for solving problems]

In order to achieve the above object, the present invention provides a welding material between an upper electrode pressurized by a pressurizing cylinder provided at the upper part of the stand of a welding machine and a lower electrode fixedly installed at the lower part of the stand. In a nut welding machine that clamps a nut and welds the nut to a workpiece, the rod to which the upper electrode of the pressurizing cylinder is attached is rotatable and vertically slidable on the upper part of the stand via a bearing member. A bracket is fixedly attached to the upper part of the stand, which can be attached to the stand and which supports the reaction force at the time of pressurization via the pressurizing cylinder.

[Effect]

According to the above configuration, the pressurizing cylinder is rotated to remove the upper electrode from the position facing the lower electrode, and then the workpiece and the nut are attached to the lower electrode, and then the upper electrode is moved again to face the lower electrode. Welding can be performed by rotating the weld to the position where it is and applying pressure and current. Therefore, it is possible to prevent the upper electrode from coming into contact with the tip of the nut supply cylinder and the nut attached to the tip, making it possible to reduce the distance between the upper and lower electrodes, thereby reducing the distance between the parts to be welded. The weldable range of shapes can be expanded.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a nut welding machine according to the present invention will be described below with reference to the drawings.

An embodiment of the present invention is shown in FIGS. 1 to 4.
In these figures, the same or equivalent parts as in the conventional example shown in FIG. 5 are designated by the same reference numerals, and their explanation will be omitted.

The feature of this invention is the mounting structure of the pressurizing cylinder on the top of the stand. The rod 4 of the pressurizing cylinder 2 is attached to the fourth rod 4 attached to the upper arm 1a of the stand 1.
Rotatable by the metal bush 11 shown in the figure.
And it is supported so as to be slidable in the vertical direction. Therefore, the pressurizing cylinder 2 is not fixed to the upper arm 1a.

The pressure of this pressure cylinder 2 is supported by a gate-shaped bracket 12 fixed to the upper surface of the upper arm 1a. An arm 13 is attached to the pressure cylinder 2 at right angles to the axial direction, and is rotatable via a rod 15 of a swinging air cylinder 14 provided on the upper arm 1a of the stand 1 and a pin 16. connected. A positioning stopper 17 is attached to the stand 1 to restrict the rotation range of the arm 13, and determines the position of the upper electrode 5 facing the lower electrode 3.

Next, the operation of this embodiment will be explained. First, the swinging air cylinder 14 is activated, and the pressurizing cylinder 2,
Rotate the rod 4 and the upper electrode 5 together in the clockwise direction shown in FIG.
Remove it from the position facing it. In this state, the upper electrode 5 is separated from the tip of the nut supply cylinder 10 and the nuts fed to this tip from the nut feeder 8 via the nut supply hose 9, and therefore does not interfere with it.

Next, the member 6 to be welded is attached by fitting the hole formed at the nut welding part of the member 6 to the pilot pin 7 of the lower electrode 3. Next, the nut 18 is attached to the pilot pin 7 of the lower electrode 3 by the nut supply cylinder 9. After the nut 18 is supplied, the swinging air cylinder 14 is operated again to rotate the upper electrode 5 so that it faces the lower electrode 3. At this time, the stop position of the upper electrode 5 is correctly positioned by the stopper 17. Then, the pressure cylinder 2 is operated to lower the upper electrode 5, and the member to be welded 6 and the nut 18 are clamped and pressurized between the upper electrode 5 and the lower electrode 3, and electrical welding is performed. At this time, the pressure applied by the pressure cylinder 2 is supported by a bracket 12 attached to the stand 1.

According to this embodiment, when feeding nuts, the upper electrode 5 is separated from the tip of the nut supply cylinder, so the tip and the nuts attached to the tip come into contact with the upper electrode 5, causing a feeding failure. Never. Therefore, the distance between the upper electrode 5 and the lower electrode 3 can be reduced, and even if the workpiece 6 has a U-shaped cross section and a small opening, it can be easily mounted on a welding machine, and the welding process can be easily performed. It becomes possible.

[Effect of idea]

As described above, according to the present invention, since the upper electrode of the nut welding machine is rotatable around the pressure cylinder, it is possible to prevent the nut supply cylinder and the nut from interfering with the upper electrode when the nut is installed, and the upper electrode can be rotated around the pressure cylinder. Since the distance between the electrode and the lower electrode can be reduced, the range of shapes of weldable members that can be welded can be expanded.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of a nut welding machine according to the present invention, Fig. 2 is a plan view of Fig. 1, Fig. 3 is a side view of Fig. 1, and Fig. 4 is a side view of Fig. 1. 5 and 6 are front views showing a conventional example. 1...Stand, 2...Pressure cylinder, 3...
Lower electrode, 4... Rod, 5... Upper electrode, 6...
...Member to be welded, 11...Metal bush (bearing member), 12...Bracket, 14...Air cylinder for swing (driving means).

Claims (1)

[Claims for Utility Model Registration] (1) A member to be welded between an upper electrode that is pressurized by a pressure cylinder provided at the top of the stand of a welding machine and a lower electrode fixedly installed at the bottom of the stand. In a nut welding machine that clamps a nut and welds the nut to a workpiece, the rod to which the upper electrode of the pressurizing cylinder is attached is rotatable and vertically slidable on the upper part of the stand via a bearing member. A nut welding machine characterized in that a bracket is fixedly mounted on the upper part of the stand to support the reaction force during pressurization via the pressurizing cylinder. (2) The nut welding machine according to claim 1, wherein the pressure cylinder and the rod are rotationally driven by a driving means fixed to the stand. (3) The nut welding machine according to claim 1 or 2, wherein the driving means for rotationally driving the pressure cylinder and the rod is an air cylinder.