JPH0731893Y2 - Welding machine uniform pressure device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a uniform electrode pressing device for two-point simultaneous welding in electric spot welding, and more particularly to an improvement of Japanese Patent Application No. 63-88161.

[Conventional technology]

Approximately frequently, in electric spot welding, the welding strength is closer to the strength of the base metal.
2 point simultaneous welding is being actively used from the standpoint of reducing the welding time to substantially 0%), further reducing the welding time substantially and reducing the frequency of welding electrode replacement (extending the electrode life). . In this two-point simultaneous welding, not only in direct spot welding but also in series welding and indirect welding, when two electrodes are energized without being uniformly pressed, unbalanced weak pressing is forced. It is well known that the electrode of No. 1 abnormally overheats, causes the electrode to melt, and amplifies the vicious cycle of causing further imbalance in the subsequent pressurization, and causes not only welding failure but also welding failure. ing.
Therefore, many studies have been conducted on the constant and even pressurization of both electrodes, and for example, a uniform pressurizing mechanism or device such as a one-sided hit prevention mechanism as seen in Japanese Utility Model Publication No. 54-5786 has been adopted. However, with these devices and mechanisms, the structure is complicated and large, the production cost is high, and it is difficult to apply them in a portable manner. In order to eliminate such a defect, as shown in Japanese Utility Model Application No. 63-88161, in the direction perpendicular to the line connecting the two electrodes,
A device that exerts a pressing force with a "line" in the middle has been developed, and its power has been exerting its power, but when this device is used in a stationary welding machine, the welding target is also compared. Since many of them are relatively large and stable or have fixed shapes, the effect can be achieved without regret, but this is a portable small welding machine (hand-handled transfer type, etc.)
When there is a small object to be welded and an irregular shape is present, the limit of the uniform pressing function of pressing with the line of the slider and the supporting round bar is exceeded. Sometimes it caused problems.

[Problems to be solved by the device]

Even for the small-sized portable spot welders described above,
Demonstrate evenly pressurizing function without causing problems,
In addition to smoothly responding to any aspect of the object to be welded,
In order to provide a uniform pressurizing device that can be applied to all welding machines, the inventors of the present invention have made diligent studies and trials, and finally have a reliable uniform pressurizing function. This has led to the completion of the "equal pressure applying device" (hereinafter simply referred to as this device).

[Means for Solving the Problems]

As means for solving the above-mentioned problems, the present invention has dealt with by applying the following means.

That is, in an electrode uniform pressurizing device of a two-point spot welding machine, an air cylinder for pressurization, a piston, and a piston rod formed in a hollow cylindrical shape, and a uniform presser housed inside the cylinder of the piston rod (the uniform pressurizer). The pressurizer includes a pressurizing support shaft pivotally supported by the piston rod, a free link pivotally supported by the pressurizing support shaft, a press roller provided at the end of the free link via the press shaft, and a pressurizing roller. And a two pressing electrodes, and a slider that receives the pressing force of the pressure roller with a line, and a disc spring that balances the pressing force of the slider and transmits it to the pressing electrode holder). The upper part is provided with a pressure electrode holder having a hole for accommodating the slider and the disc spring, a spring mechanism and an auxiliary spring for balancing the pressure operation of the pressure electrode holder.

It should be noted here that the universal link is provided so that the pressure applied to the two electrodes can be reliably and evenly applied to any form of the object to be welded.

[Action]

The function of the present invention will be described with reference to FIG. 7 (including FIG. 8) of the drawings.

If one of the pressure electrodes 35 as shown in FIG. 7 is unidirectionally struck due to a certain state, if the pressure H is applied to the pressure support shaft 22, the pressure support shaft 22 Center P and pressure roller
A pressing force of G (G≈H) at a point Q along a line connecting the contact points Q of the slider 26 and the slider 27 (the points Q are innumerable on the line, but for convenience of description, it will be described in a plane). ), Which acts on the line that connects the contact point R between the pressure electrode 35 on one side and the welded body, and the point Q that reaches the line PR of ΔPQR.
Tentative vector F ′ from (theoretical exact F ′ is the line PR ⊥
It is decomposed into a component force F acting on the opposite side equally at point Q (because it is extremely approximate), and this component force F acts more effectively than the universal link 21 of the present invention.
Since the pressure roller 26 is movable in the F direction, the idle pressure electrode 35 on the other side of the one-sided thrust is pressed against the object to be welded, so that E = E′≈1 / 2G and uniform pressure is applied. Will be done.

This means that the free link 21 and the pressurizing roller 26 continuously exert a balancing action when the pressing force H acts before reaching the extreme unbalanced state as shown in FIG. As a result, uniform pressurization is achieved without fail, so that the state shown in FIG. 7 is not reached.

Assuming now that the conventional example is shown in contrast in FIG. 8 for comparison, in the conventional example, the component force F at point Q in FIG. 8 (since line PQ is small as can be seen in the figure, this F Is a very small vector), but the pressure support shaft 22 is in direct contact with the slider 27, the F of the pressure support shaft 22 is
The movement in the direction is impossible, and therefore the one-sided state cannot be restored.

〔Example〕

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a front sectional view of the present apparatus 1, FIG. 2 shows a side partial sectional view taken along the line AA of FIG.
The BB arrow view of FIG. 2 and FIG. 2 is shown in FIG. 3 and the CC arrow view of FIG. 2 is shown in FIG.
Is attached to the apparatus frame 2, and a peculiar cylindrical hollow type piston rod 12 is attached to the piston 11, and the piston rod 12 is slidably fitted in the narrow portion of the air cylinder 10.

A uniform pressurizer 20 is housed inside the cylinder of the piston rod 12, and the uniform pressurizer 20 includes a pressurizing support shaft 22 and a free link.
21 (this free link 21 is the key point of the present invention), a pressurizing shaft 25, a pressurizing roller 26, a slider 27, and a disc spring 28. The pressurizing support shaft 22 passing in a direction perpendicular to the line connecting the electrodes 35, 35 is pivotally supported in the state shown in FIG. 3, and the pressurizing support shaft 22 is pivotally supported by the piston rod 12.

A pressure roller 26 supported by a pressure shaft 25 is provided on the other side of the free link 21 to smooth the pressure contact with the slider 27 (see FIG. 4). This slider 27 is a disc spring 28.
The pressing force is configured to be balancedly transmitted to the bottom surface of the upper hole of the pressure electrode holder 30 via the.

As can be seen in FIGS. 2 and 3, the pressure support shaft 22
The one end thereof is configured so that the pressurizing direction of the uniform pressurizer 20 is correctly regulated by the guide groove formed by partially cutting out the air cylinder 10 and the collar 15.

As described above, the pressure electrode holder 30 has an even pressure bar on the top.
20 has a perforated portion that accommodates the slider 27 and the disc spring 28,
The bottom surface receives the pressing force and transmits it to the pressure electrodes 35, 35, and naturally holds two pressure electrodes on the lower surface.

As can be seen in FIG. 4, the pressure electrode holder 30 is arranged at a right angle to the line connecting the pressure electrodes 35, 35 (that is, in parallel with the pressure support shaft 22). It is suspended by the pressure electrode holder 30 when the uniform presser 20 is lifted.
It is constructed so that it rises with.

In order to properly regulate the pressing direction of the pressing electrode holder 30, a spring mechanism 40 including a spring holder 41, a spring 42, and a pressing element 43 is provided, and the repulsive force of the spring 42 is used. Further, an auxiliary spring 45 is provided in the upper portion of the pressure electrode holder 30 in the hollow portion of the piston rod to further regulate the pressure direction.

The spring holder 41 of the spring mechanism is fitted to the lower part of the piston rod 12.

Further, at least two springs 42, pressing elements 43, and auxiliary springs 45 are attached in parallel to the line connecting the pressure electrodes 35, 35, but the number of radial elements can be increased without any problem.

Although not particularly shown in the drawing, the pressure electrodes 35, 35 are electrically connected to the transformer, and there is an insulator between the pressure electrode holder 30 and the pressure electrodes 35, 35. It goes without saying.

Further, although not included in the constituent elements of this device, it is also the same as having two counter electrodes (36).

Now, the operation of the device 1 will be described.
Place the object to be welded between 5 and the counter electrode, and air cylinder 1
By pressing 0, uniform two-point pressing starts. That is, the piston 11 descends and the piston rod
Lower 12 A pressure support shaft 22 is attached to the piston rod 12.
The free link 21 connected by
The pressing roller 26 through 25 applies a pressing force to the slider 27 by the line that is in contact with the pressing roller 26, and further absorbs the imbalance of the pressing electrodes 35 and 35 to apply pressure evenly. The pressing force of the slider 27 is transmitted to the pressure electrode holder 30 by the disc spring 28.

Thus, as described in detail in the previous section [Operation], the two pressurizing electrodes 35, 35 are evenly pressed in a constantly balanced manner.

When the two-point spot welding is completed, the pressure electrode holder 30 is lifted and restored together with both the pressure electrodes 35, 35 by the restoration operation of the air cylinder 10.

Now, FIGS. 7 and 8 of the drawings are shown as action explanatory views for explaining the action of each of the present embodiment and the conventional example, but the explanation has already been made.

Further, a front view of a small portable welding machine 50 to which the present apparatus 1 is applied is shown in FIG. 5 and a side view thereof is shown in FIG. It exerts great power. Of course, application to a large welding machine does not hinder at all.

FIG. 9 illustrates an extremely inconvenient case of the conventional example.
Since the pressure support shaft 22 only moves up and down on the machine axis XX, it is impossible to restore the pressurization electrode holder 30 to the XX axis with respect to the movement on the ZZ axis inclined by Θ degrees from the machine axis XX line. It shows the state of being done. Therefore, both pressure electrodes 35,35
However, it is inclined by Θ with respect to the welding surface and causes a one-sided phenomenon.

It is understood that the present invention is well understood to show the effect of performing reliable uniform pressurization by the universal link 21 as shown in FIG.

〔effect〕

According to the implementation of the present invention, the reliable uniform pressurization of two-point spot welding, which has been conventionally caused by the application to a small portable welding machine, is completely eliminated, and it contributes further to the spread of two-point spot welding. It is a thing.

[Brief description of drawings]

1 to 7 of the drawings show an embodiment, FIG. 1 is a front sectional view of the present apparatus, FIG. 2 is a view taken along the line AA of FIG. 1, and FIG. 3 is FIG. Fig. 2 is a BB arrow view, Fig. 4 is a CC arrow view in Fig. 2, Fig. 5 is a front sectional view of a portable welding machine to which the present apparatus is applied, and Fig. 6 is a side view thereof. FIG. 7 is an explanatory view of the operation of this device. 8 and 9 show a conventional example, FIG. 8 is an explanatory view of its operation, and FIG. 9 is a partial cross-sectional view contrasting with the present invention showing an inconvenient case. 1 …… This device, 2 …… Device frame 10 …… Air cylinder, 11 …… Piston 12 …… Piston rod, 15 …… Collar 20 …… Uniform presser, 21 …… Independent link 22 …… Pressure support shaft , 25 ...... Pressure shaft 26 ...... Pressure roller, 27 ...... Slider 28 ...... Disc spring, 30 ...... Pressure electrode holder 35 ...... Pressure electrode, 40 ...... Spring mechanism 41 ...... Spring holder , 42 ...... Spring 43 ...... Presser, 45 ...... Auxiliary spring 50 ...... Portable small welding machine.

Claims (1)

[Scope of utility model registration request] 1. An electrode uniform pressurizing device for a two-point spot welding machine, comprising: an air cylinder for pressurization, a piston, a piston rod formed into a hollow cylindrical shape, and a piston rod which is housed inside the cylinder of the piston lot. A pressure-supporting shaft that is axially supported, a free link that is axially supported by the pressure-supporting shaft, a pressure roller that is provided at the tip of the free-link via the pressure shaft, and a pressing force of the pressure roller by a line. A slider for receiving, a uniform presser including a disc spring that balances the pressure applied by the slider and transmits the pressure to the pressurizing electrode holder, and two pressurizing electrodes, the slider and the disc spring are provided on the upper part. An electrode uniform pressing device for a welding machine, comprising: a pressure electrode holder having a hole for accommodating, a spring mechanism and an auxiliary spring for balancing the pressurizing operation of the pressure electrode holder.