JPH0235415Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a spot welding machine, and more particularly to a spot welding machine equipped with an equalizing mechanism that sequentially slides a pair of electrodes into pressure contact with a workpiece.

[Prior art]

A spot welder welds by applying electricity by pressing a pair of electrodes into contact with the workpiece from both sides with the workpiece in between. In order to reduce electrical loss in the secondary cable that connects the transformer that supplies high voltage, and to make the entire device compact, the gun section is equipped with a pair of electrodes, and the transformer section that supplies current to the electrodes. Various welding machines have been proposed in which a welding machine is integrated with an equalizing mechanism that brings a pair of electrodes into pressure contact with a workpiece.

[Problem that the invention attempts to solve]

However, in conventional welding machines of this type, the transformer section, the gun section, and the equalizing mechanism are simply put together and integrated, and are not sufficiently compact.

In particular, as shown in FIG.
is fixed to the sliding part 4a of the equalizing mechanism 4,
In a welding machine in which the transformer section 2 is configured to slide integrally with the movable electrode 7a, the strength of the sliding section 4a must be ensured to support the weight of the transformer section 2, which increases the weight accordingly. The dot was hot.

Further, as shown in FIG. 4, the transformer section 2
A welding machine that equalizes only the gun part 6 by fixing it to the robot's arm 5 or the like is relatively compact, but it requires a pair of electrodes 7a and 7a provided on the gun part 6 that slide from the transformer part 2.
There was also a problem in that two shunts 8 were required as conductor paths for supplying current to each of the shunts 7b.

The object of the present invention is to solve the above-mentioned problems, and to provide a spot welding machine that is compact in structure and works reliably.

[Means for solving problems]

The spot welding machine according to the present invention includes a transformer core around which a primary winding is wound and fixedly supported by a frame, and a transformer core that penetrates through the transformer core and is supported slidably in the penetrating direction. a pair of secondary conductors whose one ends are connected via a shunt;
A pair of electrodes are fixed to each secondary conductor and arranged to face each other, and an electrode pressurizing cylinder is assembled between the two electrodes, with a driving rod attached to one of the pair of electrodes and a cylinder body attached to the other electrode. The cylinder is operated to cause the pair of electrodes to slide together with their respective secondary conductors, position the pair of electrodes across the workpiece, and sequentially bring them into pressure contact with the workpiece. In addition, the pair of electrodes is elastically supported by the transformer core in the sliding direction, and by this means, the above object is achieved.

[Effect]

According to the present invention, since the transformer core and the secondary conductor function as sliding guides for each electrode,
There is no need to separately provide a guide for sliding the electrode, and the overall structure becomes more compact.

Furthermore, since one of the pair of electrodes is elastically supported in the sliding direction by the transformer core, the sliding order of the electrodes is determined and the electrode can be brought into secure pressure contact with the workpiece.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a first embodiment of the present invention.

In this figure, the transformer section 10 includes a transformer core 14 supported on both sides by an outer frame 12 and around which a primary winding is wound;
A pair of secondary conductors 16, 1 disposed through the inside
It consists of 7.

The secondary conductors 16 and 17 are supported by ball bearings 18 on the outside of the outer frame 12, so that they can each slide in the penetrating direction. One end of the secondary conductors 16 and 17 is connected to each other by a shunt 20 formed by laminating copper plates, and the other end is connected to a pressure side electrode 22 disposed opposite to each other.
and the fixed side electrode 24, respectively.

The secondary conductors 16, 17 have hollow parts 16a, 17.
a is formed respectively, and a passage 23 communicating with this hollow part 16a is formed in the pressurizing side electrode 22, and cooling water enters from the inlet 16b, passes through the hollow part 16a, passes through the passage 23, and reaches the outlet 23a. It's starting to get better. The end of the secondary conductor 17 is inserted into and connected to the fixed side electrode 24, and a passage 25 is formed in which the secondary conductor 17 is inserted.
A pipe 26 connected to the inlet 1 is disposed with a predetermined gap from the inner peripheral surface of the passage 25, and the cooling water is supplied to the inlet 1.
It enters from 7b, passes through the hollow part 17a, the inside of the pipe 26, circulates around the outer periphery of the pipe 26 from the pipe tip 26a, and reaches the outlet 25a.

The electrodes 22 and 24 are connected via an electrode pressurizing cylinder 30, with the pressurizing side electrode 22 being fixed to the piston rod 31 of the cylinder 30, and the fixed side electrode 24 being connected to the cylinder 30 via a connector 34.
It is fixed to the cylinder body 32 of. Also,
Elastic members 36 are arranged on both sides of the transformer section 10 to keep the position of the fixed electrode 24 constant and to slide the movable electrode 22 ahead of the fixed electrode 24. Therefore, when compressed air is supplied into the cylinder chamber 30a, a force shown by arrow A acts inside the cylinder chamber 30a, and the fixed electrode 24 tries to slide in the direction of arrow B.
Since it is supported by an elastic body 36, it does not slide, and the piston rod 31 is connected to the pressure side electrode 22 and the secondary conductor 16.
It is designed to slide together in the direction of arrow C. Note that the transformer core 14 and the secondary conductors 16, 1
7 functions as a sliding guide when equalizing each electrode 22, 24.

In addition, the reference numeral 40 is a bearing with insulation properties, and the reference numeral 4
2 is an O-ring to prevent cooling water leakage, code 44
The outer frame 12 also serves as a mounting seat for a robot, etc.
A mounting plate 46 for positioning the parts 12 and 46 indicates a workpiece to be welded.

Next, the movement of each part during welding using this embodiment will be explained.

When the workpiece 46 is fixed at a predetermined position between the electrodes 22 and 24, compressed air is supplied to the cylinder chamber 30a, and the pressure-side electrode 22 slides until it comes into contact with the workpiece 46 as shown by arrow C. move. Since the workpiece 46 is fixed, when the movable electrode 22 comes into contact with the workpiece 46, the piston rod 31 cannot move any further, so the elastic body 3
6, the cylinder body 32 and the fixed side electrode 2
4. Slide the secondary conductor 17 together in the direction of arrow B to bring the stationary electrode 24 into contact with the workpiece 46.
Since the fixed side electrode 24 is elastically supported in the sliding direction by the elastic body 36, both the electrodes 22, 24
is in contact with the workpiece 46 under appropriate pressure,
In this state, electricity is applied to weld.

In the embodiment described above, the elastic body 36 was provided on the secondary conductor 17 side, and the electrode fixed to the secondary conductor 17 was used as the fixed side electrode. It is also possible to provide the electrode 22 on the fixed side electrode and the electrode 24 as the movable side electrode.

FIG. 2 shows a second embodiment of the present invention. In the previous embodiment, only the electrode pressurizing cylinder 30 was used as a means for sliding each electrode, but in this embodiment, in addition to the cylinder 30, The difference is that a solenoid valve 50 is added, and the rest is the same as the previous embodiment, and the same reference numerals are given, and the explanation thereof will be omitted.

[Effect of idea]

As is clear from the above explanation, according to the present invention, the sliding mechanism for equalizing a pair of electrodes is integrated into the transformer, making it possible to obtain a compact spot welding machine and achieve weight reduction. can. As a result, it can be used even in narrow spaces and has a wide range of applications. Furthermore, since the pair of electrodes is elastically supported by the transformer core in the sliding direction, the electrodes can be reliably applied to the workpiece.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing a first embodiment of the present invention, Fig. 2 is a side view showing a second embodiment of the invention, and Figs. 3 and 4 are side views of a conventional spot welding machine. It is a diagram. 10...Transformer part, 12...Outer frame, 14...
Transformer core, 16, 17...Secondary conductor, 18...
...ball bearing, 20...shunt, 22...
...pressure side electrode, 24... fixed side electrode, 30... electrode pressurization cylinder, 36... elastic body.

Claims (1)

[Scope of utility model registration request] The primary winding is wound around a transformer core that is fixedly supported by a frame, and the transformer core extends through the transformer core and is slidably supported in the penetrating direction and connected at one end via a shunt. a pair of secondary conductors, a pair of electrodes fixed to each secondary conductor and arranged facing each other, an elastic body interposed between the transformer core and at least one of the electrodes; A driving rod is attached to one of the electrodes, a cylinder body is attached to the other electrode, and an electrode pressurizing cylinder is assembled between the two electrodes, and the operation of this cylinder causes the pair of electrodes to be moved between the two electrodes. The pair of electrodes are positioned across the workpiece by sliding together with the next conductor, and are sequentially brought into pressure contact with the workpiece, and the pair of electrodes is elastically moved against the transformer core in the sliding direction. A spot welding machine characterized by supporting.