JPH04294875A - C type welding gun device - Google Patents

Abstract

PURPOSE:To reduce the width of a welding gun by putting a fixed gun arm and an ounce copper plate for power feeding to a movable gun arm in the with of a plane of projection of a transformer in the DC C-type welding gun on which the transformer is mounted. CONSTITUTION:A center tap 5b of the transformer 5 is connected to the movable gun arm via the ounce copper plate 11. A tail end part 4b of the fixed gun arm 4 is squeezed and fixed between a couple of terminal plates 5c and 5c of the transformer via rectifiers 6 and 6. Both terminal plates are arranged so that the center between both terminal plates is offset on the one side in the cross direction of the transformer and consequently, the fixed gun arm is arranged by being offset on the one side part in the cross direction of the plane of projection of the transformer. The ounce copper plate is arranged on the other end in the cross direction of the plane of projection.

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-type welding gun device equipped with a transformer.

0002

[Prior Art] This type of welding gun device includes a pressurizing cylinder, a movable gun arm attached to a piston rod that projects forward of the pressurizing cylinder, and a movable gun arm that extends from the pressurizing cylinder side to the forward end of the movable gun arm. Generally, the gun includes a fixed gun arm facing the distal end of the gun, and a transformer provided at the tail end of the fixed gun arm. In such a welding gun device, according to Japanese Utility Model Application Publication No. 2-108582, the center tap of the secondary coil of the transformer is connected to the movable gun arm via an ounce copper plate, and the center tap of the secondary coil of the transformer is connected to the movable gun arm through an ounce copper plate. The tail end of the fixed gun arm is clamped and fixed between a pair of opposing terminal plates with a rectifier interposed between each terminal plate, so that power can be directly supplied from the rectifier of the fixed gun arm. What has been done is known. In this device, both terminal plates are arranged symmetrically with respect to the center line in the widthwise center of the transformer, and a fixed gun arm extends forward from between both terminal plates along the center line, and on one side of the fixed gun arm. The ounce copper plate is arranged so as not to come into contact with this.

0003

[Problems to be Solved by the Invention] In the above system, since the fixed gun arm is arranged at the center in the width direction of the projection surface toward the front of the transformer, the ounce copper plate arranged on one side of the gun arm is placed on the outside of the projection surface. This protrudes and increases the width of the welding gun, which poses a problem when welding a workpiece by inserting the welding gun into a narrow recess or the like. In view of the above points, an object of the present invention is to provide a C-type welding gun device in which an ounce copper plate is accommodated within the projection plane of a transformer so that the width can be reduced as much as possible.

0004

[Means for solving the problem] In order to achieve the above purpose,
The present invention includes a pressurizing cylinder, a movable gun arm attached to a piston rod protruding forward of the pressurizing cylinder, and a fixed gun arm extending from the pressurizing cylinder side to the forward end of the movable gun arm and facing the tip of the movable gun arm. , a C-type welding gun device equipped with a transformer provided on the tail end side of a fixed gun arm, in which the center tap of the secondary coil of the transformer is connected to the movable gun arm via an ounce copper plate, and the center tap of the secondary coil of the transformer is connected to the movable gun arm via an ounce copper plate. The tail end of the fixed gun arm is clamped and fixed between a pair of terminal plates arranged opposite to each other in the width direction of the transformer connected to both ends, with a rectifier interposed between each of the terminal plates. Both terminal boards are arranged so that the center between the two terminal boards is offset to one side of the center in the width direction of the transformer, and the fixed gun arm is placed on one side in the width direction of the projection surface toward the front of the transformer. On the other side in the width direction, the ounce copper plate was placed in parallel.

[0005]

[Operation] Since the fixed gun arm is arranged offset to one side in the width direction of the projection surface of the transformer, the other side in the width direction of the projection surface becomes an empty space, and by placing an ounce copper plate there, The fixed gun arm and the ounce copper plate can be arranged in a space-efficient manner so that both fit within the width of the projection surface of the transformer.

[0006]

[Example] Referring to FIG. 1, 1 indicates a pressurized cylinder,
A piston rod 1a that projects forward of the pressurizing cylinder 1
A movable gun arm 3 is attached to the pressurizing cylinder 1 via an insulating material 2, and a fixed gun arm 4 is provided above the pressurizing cylinder 1, extending beyond the movable gun arm 3 and facing the tip of the movable gun arm 3. Welding by sandwiching the workpiece between electrodes 3a and 4a attached to the opposite surfaces of the tips of 4C
A type welding gun was constructed. A transformer 5 is provided on the tail end side of the fixed gun arm 4, and the secondary coil 5a of the transformer 5 has a center tap 5b and terminals at both ends of the coil opposite in the width direction of the transformer 5, as shown in FIG. board 5c,
5c, and these center taps 5b and terminal plates 5c, 5c were made to protrude from the front end surface of the transformer 5, as shown in FIGS. 1 and 2. And both terminal plates 5c, 5c
In the meantime, as shown in FIGS. 2 and 3, the plate-shaped tail end 4b of the fixed gun arm 4 is inserted between each terminal plate 5c with a rectifier 6 interposed between the two terminal plates. 5c, 5
c, a pair of presser plates 7, 7 provided on both outer sides in the opposing direction.
The fixed gun arm 4 was clamped and fixed between the two terminal plates 5c, 5c via the rectifiers 6, 6 by means of a tightening bolt 8 via a disc spring 9. Further, the center tap 5b is connected to the terminal portion 3b projecting diagonally upward of the movable gun arm 3 as shown in FIG. A direct current that has been full-wave rectified by the pair of rectifiers 6 and 6 is passed between the fixed gun arm 4 and the fixed gun arm 4, and spot welding of the workpiece that is squeezed between the electrodes 3a and 4a of both the gun arms 3 and 4 is carried out. I made it. The pressurizing cylinder 1 is composed of a cylinder barrel 1c into which a piston 1b is inserted, head covers 1d, 1d at both ends of the barrel 1c, and a plurality of tie rods 1e extending between the covers 1d, 1d. A transformer 5 was fixed to the upper surface of a support bracket 12 formed integrally with the head cover 1d on the tail end side, and the fixed gun arm 4 was supported on the pressurizing cylinder 1 via the transformer 5.

[0007] Both terminal plates 5c, 5c are
The gun arm 4 is arranged so that the center between c and 5c is offset to one side of the center in the width direction of the transformer 5, and the gun arm 4 is fixed to one side across the center line a in the width direction of the forward projection surface of the transformer 5. and an ounce copper plate 11 are arranged side by side on the other side so that both the fixed gun arm 4 and the ounce copper plate 11 fit within the width of the projection plane. The fixed gun arm 4 is reinforced with ribs 4c formed on the outer surface opposite to the ounce copper plate 11, and furthermore, the tip of the arm 4 is bulged inward to oppose the tip of the movable gun arm 3. did.

The pressure cylinder 1 is slidably supported by a gun bracket 13 attached to the operating end of a moving mechanism such as a robot. In this embodiment, in order to simplify the guide mechanism, the pressure cylinder 1 is is slidably inserted and supported by a pair of guide sleeves 13a, 13a formed on the gun bracket 13 at a pair of lower tie rods 1e, 1e, and the entire device including the pressure cylinder 1 and the gun bracket 13 is supported. It was made to fit within the width of transformer 5. Further, a rod portion 1f protruding toward the rear of the pressurizing cylinder 1 is integrally formed on the piston rod 1a, and a stopper portion 13b facing the rod 1f is integrally formed on the gun bracket 13, so that the piston can be stopped when the gun is opened. rod 1
When the movable gun arm 3 is opened to a predetermined opening degree, the rod part 1f comes into contact with the stopper part 13b,
Thereafter, the pressurizing cylinder 1 moves forward with respect to the gun bracket 13 due to the contact reaction force, and the fixed gun arm 4 is opened forward, so that a so-called equalizing operation is applied.

[0009]

As is clear from the above description, according to the present invention, the width of the welding gun can be reduced by fitting the fixed gun arm and the ounce copper plate for power supply to the movable gun arm within the width of the projection surface of the transformer. It has the effect of being able to weld in narrow recessed areas without any problems.

[Brief explanation of the drawing]

[Fig. 1] A partially cutaway side view of an example of the device of the present invention

[Figure 2]　　　　　　　　　　Plan view

[Figure 3] Cutaway sectional view taken along line III-III in Figure 1

[Figure 4] Cross-sectional view taken along the line IV-IV in Figure 1

[Figure 5]
Perspective view of the secondary coil of the transformer

[Explanation of symbols]

1 Pressure cylinder 1a Piston rod
3 Movable gun arm 4 Fixed gun arm 5 Transformer
5a Secondary coil 5b Center tap 5c Terminal board
6 Rectifier

Claims (1)

[Claims] 1. A pressurizing cylinder, a movable gun arm attached to a piston rod protruding forward of the pressurizing cylinder, and a fixed gun arm extending from the pressurizing cylinder side to the forward end of the movable gun arm and facing the tip of the movable gun arm. and,
C equipped with a transformer provided on the tail end side of the fixed gun arm
This is a welding gun device in which the center tap of the secondary coil of the transformer is connected to the movable gun arm via an ounce copper plate, and a pair of In a device in which the tail end of a gun arm fixed between terminal plates is clamped and fixed with a rectifier interposed between each terminal plate, the terminal plates are fixed so that the center between the two terminal plates is the width of the transformer. The fixed gun arm is arranged so as to be offset to one side of the direction center, and the fixed gun arm is juxtaposed on one side in the width direction of a projection surface toward the front of the transformer, and the ounce copper plate is arranged in parallel on the other side in the width direction of the projection surface. A C-type welding gun device characterized by the following.