JPH0428704Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a resistance welding machine capable of performing projection welding, spot welding, etc.

[Conventional technology]

There are two types of resistance welding: direct and indirect, but conventional resistance welding machines are dedicated machines that can perform only one type of resistance welding.

FIG. 2A is a diagram illustrating a conventional direct type resistance welding machine, in which 1 is an upper welding electrode, 1' is an upper welding electrode chip detachably supported on the upper welding electrode 1, and 2 is a lower welding electrode. , 2' is a lower welding electrode chip detachably supported on the lower welding electrode 2, and 3 and 4 are first and second workpieces sandwiched between the upper welding electrode chip 1' and the lower welding electrode chip 2'. It is a thing.

Workpieces 3 and 4 are welded by upper and lower welding electrodes 1 and 2.
Welding current is passed between the upper and lower welding electrodes 1 and 2 while applying a predetermined pressure or increasing the pressure to weld the objects 3 and 4 to be welded.
In this direct method of resistance welding, welding current flows from the upper welding electrode tip 1' to the outer surface of the workpiece 3
Inside → its welding surface → welding surface of workpiece 4 →
Since the flow flows from the inside to the outer surface of the lower welding electrode tip 2', an indentation is formed on the outer surface of each of the objects to be welded 3 and 4. In the case of items that require aesthetic appeal, such as home appliances, the flow is shown in Figure B. An indirect type resistance welding machine such as this is used.

In FIG. 2B, the same symbols as those shown in FIG. 2A indicate corresponding members, and 5 is an electrically insulating plate fixed on the work table 6.

In such indirect type resistance welding, the welding current from the first welding electrode tip 1' passes through the workpiece 3 → the welding surface of the workpiece 4 → the inside → the electrode pressurizing surface, and then flows through the second welding electrode tip 1'. Since the welding fluid flows to the welding electrode tip 2', no indentation is created on one outer surface 4a of the workpiece 4 due to welding.

[Problem that the invention attempts to solve]

However, with conventional resistance welding machines, direct type resistance welding and indirect type resistance welding can only be performed with dedicated resistance welding machines, and there are no resistance welding machines that can perform both with a single resistance welding machine. do not. Therefore, if it is desired to perform both direct resistance welding and indirect resistance welding, one dedicated resistance welding machine must be provided for each.

In addition, there is already a technical idea to selectively perform direct resistance welding and indirect resistance welding with one resistance welding machine, but the welding electrodes used for these welding cannot be easily attached and detached, so Depending on the shape and size of the object to be welded, the welding electrode used in indirect resistance welding may sometimes get in the way during direct welding.

In order to solve these problems, the present invention provides a resistance welding machine in which an indirect type resistance welding machine can be added to or removed from the conventional direct type resistance welding machine as needed. It is.

[Means for solving problems]

Therefore, this invention provides a resistance welding machine that is equipped with first and second welding electrodes that can move relatively in both directions and that can pressurize the first and second objects to be welded from both sides and apply welding current. an electrically insulating substrate removably disposed on the second welding electrode;
The first and second welding electrodes are positioned approximately parallel to the welding electrodes.
It is removably attached by the joint part of
a third welding electrode selectively subjected to resistance welding;
and selectively coupled by the first joint portion to selectively drive the third welding electrode so that the third welding electrode can apply a pressing force to the second workpiece. It is equipped with a drive mechanism section that can be used.

[Effect]

By providing such a means, when indirect welding is desired, the third welding electrode can be easily attached in a short time, and the welding current can be passed between the first and second welding electrodes. It is possible to selectively perform either direct type resistance welding, which is performed by applying a welding current between the first and third welding electrodes, or indirect type resistance welding, which is performed by passing a welding current between the first and third welding electrodes. Since the third welding electrode can be easily removed in a short time when indirect welding is not required, the third welding electrode does not get in the way when direct welding is performed.

〔Example〕

An embodiment of a resistance welding machine according to the present invention will be explained with reference to FIG.

In the figure, 7 is an electrode holder that supports the welding electrode 1, 8 is a cylinder fixed to the upper arm 9 and equipped with a cylinder rod 8' coupled to the electrode holder 7, and 10 is a flexible conductor connected to the electrode holder 7. , 11 is a power supply conductor connected to this flexible conductor, 12 is an indirect welding mechanism support fixed to the upper arm 9 and extending perpendicularly from this upper arm, 13 is a cylinder fixed to the support 12, and 14 is one end. is connected to the cylinder rod 13' of the cylinder 13, and the other end is connected to the pressure transmission bar 16 via the first joint part 15. The drive rod 17 has one end fixed to the support 12 and the other end. is a fixed rod connected to the pressurizing force transmission bar 16 via a second joint portion 18 serving as a fulcrum, 19 is an intermediate conductor fixed to the pressurizing force transmitting bar 16, and 20 is a flexible conductor connected to the intermediate conductor 19. , 21 is a lower arm to which the flexible conductor 20 is connected. Here welding electrode 2
are supported by the intermediate conductor 19 and electrically connected. Further, the conductive block 6' fixed on the lower arm 21 functions as a welding electrode that cooperates with the welding electrode 1 during direct type resistance welding, and also functions with the electrically insulating plate 5 during indirect type resistance welding. It acts as a work table.

First, a case where indirect type resistance welding is performed using a resistance welding machine having such a structure will be described.

In this case, as shown in the figure, an electrically insulating plate 5 is placed on a conductive block 6', and one workpiece 4 is placed on it, and the other workpiece 4 is placed so that the welded area coincides with the electrically insulating plate 5. Object 3 is stacked.

In this state, as the cylinder 8 is operated and the cylinder rod 8' is lowered, the electrode holder 7, welding electrode 1, and welding electrode tip 1' are lowered, and the workpieces 3 and 4 are welded at a predetermined position. Apply pressure. At this time, the cylinder 13 also starts operating at approximately the same time as the cylinder 8 starts operating, and as the cylinder rod 13' retreats in the direction of the arrow a, the pressurizing force transmission bar 16 is moved in the direction of the arrow b around the pin of the joint portion 18. The welding electrode 2 and the welding electrode tip 2' are pressed down via the intermediate conductor 19. The cylinder rod 13' stops its backward movement at a level at which the welding electrode 2 and the welding electrode tip 2' maintain a predetermined pressure applied to the workpiece 4.

After that, a current is applied to the welding electrode 1 through the power supply conductor 11, the flexible conductor 10, and the electrode holder 7, and this welding current is applied from one side of the workpiece 4 through the welding electrode tip 1' and the workpiece 3. It flows inside and flows out from the same surface to the welding electrode tip 2',
Furthermore, it flows to the lower arm 21 through the welding electrode 2, the intermediate conductor 19, and the flexible conductor 20.

In this way, indirect type resistance welding is performed, but in preparation for the next cycle, the cylinder 1
3 operates to advance the cylinder rod 13'.
Along with this, the joint portion 1 of the pressurizing force transmission bar 16
The side where 5 is located is pushed down, and the other side rotates about the pin of the joint portion 18 in the direction opposite to the arrow direction b. The intermediate conductor 19 and the welding electrode 2 are raised away from the surface of the workpiece 4 to a position where they do not interfere with the removal and supply of the workpieces 3 and 4,
When the cylinder 13 stops operating, it stops and prepares for the next cycle of resistance welding.

When performing the next direct method resistance welding, the welding electrode 2 is not required, so the cylinder rod 13' is held in the advanced state, that is, the welding electrode 2 and the welding electrode 2' are held in the raised state, or By removing the pins from the joints 15 and 18, the pressure transmission bar 16 is removed from the drive rod 14 and the fixed rod 17. Furthermore, by removing the intermediate conductor 19 from the flexible conductor 20, the pressurizing force transmission bar 16, the intermediate conductor 19, and the welding electrode 2 can be completely separated from the resistance welding machine, and these can be completely removed as necessary during direct resistance welding. It is removable. After bringing the welding electrode 2 into one of the above states and removing the electrically insulating plate 5 on the conductive block 6', the workpieces 4 and 3 to be welded are stacked directly on the conductive block 6', and the workpieces 4 and 3 are placed under pressure. Direct resistance welding is performed by passing a welding current between the welding electrode 1 and the conductive block 6'.

Here, the cylinder 13 with the cylinder rod 13' may of course be a drive device consisting of a combination of a conventional reverse rotatable motor, a gear connected to the motor, and a rack having teeth meshing with the teeth of the gear.

Although the explanation of the electrical system has been omitted, it is preferable that the timing of the drive signals for the cylinders 8 and 13 be the same. But cylinder 1
The drive signal circuit or power supply circuit No. 3 can be selectively turned on and off by a manual switch, and the manual switch is opened during direct resistance welding.

[Effect of idea]

As described above, according to the present invention, the first welding electrode, the second and third welding electrodes that can selectively cooperate with the first welding electrode to flow the welding current, and the third welding electrode are driven. The drive mechanism is combined with an electrically insulating plate that is selectively added to allow the second welding electrode to function as a work table, and the structure allows the third welding electrode and its related mechanisms to be easily attached and detached. Indirect type resistance welding and directed type resistance welding can be selectively performed with a first-generation resistance welding machine without the welding electrode and related parts of No. 3 getting in the way.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining an embodiment of a resistance welding machine according to the present invention, and FIGS. 2A and 2B are diagrams for explaining direct type and indirect type resistance welding, respectively. 1, 2... Welding electrode, 1', 2'... Welding electrode chip, 3, 4... Work to be welded, 5... Electrical insulating plate, 6'... Conductive block, 7... Electrode holder,
8...Cylinder, 9...Upper arm, 10, 20
... Flexible conductor, 11 ... Power supply conductor, 12
... Indirect welding mechanism support body, 13 ... Cylinder, 14 ... Movable rod, 15, 18 ... Joint part, 16 ... Pressure force transmission bar, 17 ...
Fixed rod, 19... intermediate conductor, 21... lower arm.

Claims (1)

[Scope of utility model registration request] In a resistance welding machine, the resistance welding machine is equipped with first and second welding electrodes that can move relatively in both directions and can pressurize the first and second objects to be welded from both sides to flow welding current. an electrically insulating substrate removably disposed on the welding electrode, removably attached to the first and second joints so as to be positioned substantially parallel to the first welding electrode, and selectively subjected to resistance welding; a third welding electrode that is selectively coupled to the third welding electrode by the first joint portion so that the third welding electrode can apply a pressing force to the second workpiece; resistance welding in which a welding current is passed between the first and second welding electrodes, and the first and third welding electrodes are A resistance welding machine is characterized in that it selectively performs either resistance welding by flowing a welding current during the welding process.