JPH08307B2 - C-type welding gun device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC type C welding gun device equipped with a transformer.

[0002]

2. Description of the Related Art A welding gun device of this type includes a pressure cylinder, a movable gun arm attached to a piston rod protruding toward the tip of the pressure cylinder, and a movable gun arm extending from the pressure cylinder side to the tip of the movable gun arm. It is generally provided with a fixed gun arm facing the tip of the and a transformer provided on the tail end side of the fixed gun arm. In such a welding gun device, according to Japanese Utility Model Laid-Open No. 2-108582, a center tap of a secondary coil of a transformer is connected to a movable gun arm through an ounce copper plate, and a pair of opposingly arranged continuous ends of the secondary coil are arranged. It is known that the tail end portion of the fixed gun arm is pinched and fixed between the terminal plates of the fixed gun arm with the rectifiers interposed between the terminal plates and the fixed gun arm can be directly fed from the rectifier. There is.
With this, both of the terminal plates are formed integrally with the secondary coil, and the transformer and the fixed gun arm are mechanically connected to each other at the clamping fixing point between the tail end of the gun arm and both terminal plates to apply the fixed gun arm. The transformer is fixed to a support bracket attached to the pressure cylinder, and the transformer is supported by the bracket via a fixed gun arm.

[0003]

A rectifier for a welding gun has a short life because a high current flows from the transformer, and requires frequent replacement of the rectifier. In the above conventional device, the fixed gun arm together with the transformer must be removed from the welding gun to perform the rectifier replacement work. Therefore, each time the rectifier is replaced, the wiring to the primary coil of the transformer must be removed, and a heavy weight transformer must be attached. It is necessary to carry the fixed gun arm as it is, and the replacement work becomes troublesome. Also, when pinching and fixing the tail end of the fixed gun arm via a rectifier between both terminal plates, make sure that both terminals are in proper surface contact with the facing surface of the terminal plate and the tail end of the fixed gun arm. Since it is necessary to uniformly tighten the plate at a plurality of locations around the plate, it takes a lot of time to adjust the plate, and the replacement work takes a long time. During that time, the welding work must be stopped, which lowers the productivity. Further, in the above-mentioned conventional apparatus, since the fixed gun arm is attached to the pressurizing cylinder via the support bracket which is separate from the pressurizing cylinder, the number of parts increases and the cost increases. In view of the above points, the present invention has a simple structure C that enables the rectifier replacement work to be performed in a short time without removing the transformer.
It is an object of the present invention to provide a mold welding gun device.

[0004]

In order to achieve the above object,
According to the present invention, a pressurizing cylinder, a movable gun arm attached to a piston rod protruding toward the tip of the pressurizing cylinder, and a fixed gun arm extending from the pressurizing cylinder side to the tip of the movable gun arm and facing the tip of the movable gun arm. A C-type welding gun device including a transformer provided on the tail end side of a fixed gun arm, wherein a center tap of a secondary coil of the transformer is connected to a movable gun arm via an ounce copper plate, and both ends of the secondary coil are connected. A pair of terminal plates arranged opposite to each other, the tail end portion of the fixed gun arm is sandwiched and fixed with a rectifier interposed between the terminal plates and the two terminal plates. It is detachably attached to the taps on both ends of the next coil, and a fixed gun arm is attached to the head cover at the tip of the pressurizing cylinder, and an attachment seat for the arm is attached and detached. A head cover detachably transformer of transformer mounting seat of the cylinder of the tail formed respectively integrally.

[0005]

When the rectifier is replaced, the terminal plate is separated from the tap of the secondary coil, the fixed gun arm is separated from the arm mounting seat, and the fixed gun arm, the terminal plate and the rectifier are detached as one unit. At this time, the transformer may remain fixed to the transformer mounting seat, and the wiring to the primary coil does not have to be tampered with. After removing the unit, you may disassemble the unit, replace the rectifier with a new one, and then reassemble the unit and attach it to the welding gun, but you can attach another unit prepared in advance to the welding gun. If so, the replacement work time can be significantly shortened. Even if such another unit is used, the expensive one is only the rectifier and the expensive one such as the transformer is not included in the unit, so there is no problem on the left side in terms of cost, and the fixed gun arm and terminal board of the unit removed this time The cost problem can be solved by reusing the unit for the next unit. By the way, if the terminal plate is detachably attached to the tap of the secondary coil, the mechanical coupling strength between the fixed gun arm and the transformer is lowered. However, in the present invention, the fixed gun arm and the transformer are respectively used for the arm and the transformer. There is no problem because it is attached to the mounting seat for. Moreover, since both mounting seats are formed integrally with the head covers at both ends of the pressure cylinder, the number of parts does not increase, and the structure can be simplified.

Further, in order to be able to perform the work of mounting the fixed gun arm to the arm mounting seat without being disturbed by the piston rod inserted into the head cover on the tip side forming the mounting seat, the piston rod axis and It is desirable to dispose the fixed gun arm and the arm mounting seat offset to one side of the center plane with the plane including the center line of the center of the transformer in the width direction as the center plane. By the way, in the above conventional device,
The fixed gun arm is arranged along the center plane.Therefore, if the ounce copper plate for power supply to the movable gun arm is arranged on the side of the fixed gun arm so that it does not come in contact with it, the ounce copper plate will be located on the side of the center plane. It overhangs greatly and the width of the welding gun increases. On the other hand, if the fixed gun arm is offset to one side of the center plane, the ounce copper plate can be placed close to the center plane in the space on the other side of the center plane, and the width of the welding gun can be narrowed. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numeral 1 denotes a pressure cylinder,
Piston rod 1a projecting ahead of the pressure cylinder 1
A movable gun arm 3 is attached to the movable cylinder arm 3 via an insulating material 2, and a fixed gun arm 4 is provided on the upper side of the pressurizing cylinder 1 so as to extend ahead of the movable gun arm 3 and face the tip of the movable gun arm 3. A C-type welding gun for sandwiching and welding a work between the electrodes 3a, 4a attached to the facing surface of the tip of No. 4 was constructed. A transformer 5 is provided on the tail end side of the fixed gun arm 4, and a secondary coil 5a of the transformer 5 has a center tap 5b, as shown in FIG.
The taps 5c and 5c at both ends of the coil are integrally formed, and these taps 5b and 5c are projected on the tip end surface of the transformer 5 as shown in FIGS. And tap 5 at both ends
c and 5c, a pair of terminal plates 6 and 6 are opposed to each other in the width direction of the transformer 5 and fastened with bolts 7. Between the terminal plates 6 and 6, as shown in FIGS. The tail end portion 4b formed in the plate shape is formed between the terminal plates 6 and the rectifier 8 respectively.
Inserted in a state in which the terminal plates 6 and 6 are interposed, and the terminal plates 6 and 6 are sandwiched by a plurality of tightening bolts 10 between the pair of holding plates 9 and 9 provided on both outer sides in the opposite direction via the disc spring 11. The tail end portion 4b of the fixed gun arm 4 was clamped and fixed between the two terminal plates 6 and 6 via the rectifiers 8 and 8. Also, the center tap 5
b for power feeding relay member 12 and ounce copper plate 13
Through a terminal portion 3b formed in the movable gun arm 3 through, and thus, a direct current that is full-wave rectified by the pair of rectifiers 8, 8 flows between the movable gun arm 3 and the fixed gun arm 4, The spot welding of the work sandwiched between the electrodes 3a, 4a of both gun arms 3, 4 was performed.

The pressure cylinder 1 includes a cylinder barrel 1c having a piston 1b inserted therein, head covers 1d and 1d at both ends of the barrel 1c, and both head covers 1d and 1d.
It is composed of a plurality of tie rods 1e extending therebetween, and an arm mounting seat 14 is integrally formed on the upper edge of the head cover 1d on the tip side, and the fixed gun arm 4 is attached to the mounting seat 14 at its tail end portion. A bolt 16 is fixed to the lower surface of 4b through an insulating material 15, and a transformer mounting seat 17 is integrally formed on the upper edge of the tail end side head cover 1d.
The transformer 5 was fastened with bolts 18 at the lower surface of the tip end thereof. The arm mounting seat 14 and the fixed gun arm 4 are connected to the axis of the piston rod 1 a of the pressure cylinder 1 and the transformer 5.
Is arranged offset to one side with respect to the center plane a of the welding gun including the center line of the center in the width direction of the welding gun, whereby the mounting work of the fixed gun arm 4 by the bolt 16 to the arm mounting seat 14 is performed by the piston rod. 1a so that it can be performed without being disturbed to the left, and the other side of the center plane a is used as an empty space where the fixed gun arm 4 does not exist. I tried not to overhang it to the side. In this embodiment, the pressurizing cylinder 1 and the transformer 5 are formed to have a substantially equal width, and the movable gun arm 3, the fixed gun arm 4 and the ounce copper plate 13 are all accommodated within this width.

The pressurizing cylinder 1 is slidably supported by a gun bracket 20 attached to an operating end 19 of a moving mechanism such as a robot. In this embodiment, the pressurizing cylinder 1 is added in order to make the sliding guide mechanism small and simple. The pressure cylinder 1 to the lower one
Gun bracket 20 on the pair of tie rods 1e, 1e
The pair of guide sleeves 20a, 20a formed in the above were slidably inserted and supported. Further, the piston rod 1a is integrally formed with a rod portion 1f projecting to the tail of the pressure cylinder 1, and the gun bracket 20 is provided with the rod portion 1f.
When the movable gun arm 3 is opened to a predetermined opening when the piston rod 1a is retracted when the gun is opened, the stopper portion 20b is formed to face the stopper portion 2b.
0b, and thereafter, the pressurizing cylinder 1 is moved forward with respect to the gun bracket 20 by the contact reaction force to open the fixed gun arm 4 forward, so that a so-called equalizing operation is given.

By the way, as described above, the terminal plate 6 is tapped 5
If it is detachably attached to c by bolts 7, it becomes possible to handle the terminal plate 6, the rectifier 8 and the fixed gun arm 4 as a single unit while holding them fixed by the pressing plate 9, and the life of the rectifier 8 is exhausted. At this time, the fixing of the terminal plate 6 and the tap 5c and the fixing of the fixed gun arm 4 and the arm mounting seat 14 can be released, and the rectifier 8 can be replaced in units. The rectifier 8 needs to be surely brought into surface contact with the respective facing surfaces of the tail end portion 4b of the fixed gun arm 4 and the terminal plate 6, so that the tightening torques of the plurality of tightening bolts 10 of the holding plate 9 can be made uniform. It is necessary to adjust the tightening accurately so that the work will take time, but it is necessary for the replacement work by preparing the tightening adjusted unit in advance and replacing it in units as described above. You can save time.

[0011]

As is apparent from the above description, according to the invention of claim 1, the terminal plate can be separated from the tap of the transformer and the rectifier can be replaced without removing the transformer. This makes it easier to handle, and the terminal plate, rectifier, and fixed gun arm can be handled as a single unit with the pressure clamp fixed.By exchanging the rectifier on a unit-by-unit basis, troublesome tightening adjustment work can be performed. Therefore, the time required for replacement work can be shortened and productivity can be improved. Further, even if the unit is replaced in this way, since the expensive transformer is not included in this unit, a problem such as an increase in cost does not occur. Furthermore, since the fixed gun arm and the transformer are separately supported by a pair of mounting seats integrally formed on the head covers at both ends of the pressure cylinder, the fixed gun arm and the transformer can be separated from each other by separating the terminal plate from the tap. There is no problem even if the mechanical connection strength between them is reduced, and since it is not necessary to separately provide the support brackets for the fixed gun arm and the transformer, the structure can be simplified. Further, according to the invention of claim 2, the work of attaching the fixed gun arm to the arm mounting seat can be easily performed without being hindered by the piston rod, and the ounce copper plate for supplying power to the movable gun arm is located on the center plane side. It can be arranged so that it does not overhang to one side, and the width of the welding gun can be narrowed.

[Brief description of drawings]

FIG. 1 is a side view in which a part of an example of the device of the present invention is removed.

FIG. 2 is a plan view thereof.

FIG. 3 is a sectional view taken along the line III-III in FIG.

4 is a sectional view taken along the line IV-IV in FIG.

FIG. 5 is a perspective view of a secondary coil of a transformer.

[Explanation of symbols] 1 pressure cylinder 1a piston rod 1b head cover 3 movable gun arm 4 fixed gun arm 5 transformer 5a secondary coil 5b center tap 5c both ends tap 6 terminal plate 8 rectifier 13 ounce copper plate 14 arm mounting seat 17 transformer mounting seat

Claims (2)

[Claims] 1. A pressurizing cylinder, and a movable gun arm attached to a piston rod projecting ahead of the pressurizing cylinder,
A C-type welding gun device comprising a fixed gun arm extending from the pressure cylinder side to the tip of the movable gun arm and facing the tip of the movable gun arm, and a transformer provided on the tail end side of the fixed gun arm. The center tap of the next coil is connected to the movable gun arm via an ounce copper plate, and the tail end of the fixed gun arm is connected to each terminal plate between a pair of terminal plates arranged facing each other at both ends of the secondary coil. In a case where a rectifier is interposed between the terminals, the terminal plates are detachably attached to the taps at both ends of the secondary coil, and a fixed gun arm is attached to and detached from the head cover at the tip of the pressure cylinder. It is characterized in that a flexible arm mounting seat and a transformer mounting seat on which the transformer is detachably attached to the head cover at the tail end of the pressure cylinder are integrally formed. C-type welding gun device according to. 2. The fixed gun arm and the arm mounting seat are arranged offset to one side of the center plane with a plane including the center line of the center of the transformer in the width direction and the axis line of the piston rod as the center plane. The C-type welding gun device according to claim 1, wherein the ounce copper plate is arranged in the space on the other side of the center plane.