JP2571828Y2 - Spot welding gun - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spot welding gun for welding panels and the like.

[0002]

2. Description of the Related Art As shown in FIG. 10, a conventional general spot welding gun has a shank 3a, 3b and a movable arm 1b rotatably connected to a fixed arm 1a by a pivot 2. Through the electrode tip 4a,
4b.

When spot welding the work W with such a spot welding gun, the back bar 5 is brought into contact with the tip of the electrode tip 4a on the side of the fixed arm 1a so as not to make a dent on the work W. The work W is applied to the back bar 5 and pressurized by the movable electrode tip 4b.

[0004]

As shown in FIG. 10, the back bar 5 has a structure supported by a bracket 6 of an L-shaped leaf spring fixed to a fixed arm 1a by a bolt 7. Therefore, since the back bar 5 floats on the bracket 6 of the leaf spring, the bracket 6 may be broken due to metal fatigue.

[0005] In addition, when the electrode tip 4a is replaced, the back bar 5 needs to be removed by loosening the bolt 7 with a tool, so that the tip cannot be quickly replaced.
Further, it is necessary to machine a bolt screw hole and a seating surface for fixing the bracket 6 for attaching the back bar to the fixed arm 1a.

An object of the present invention is to provide a spot welding gun which solves the above-mentioned conventional problems.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide an electrode tip via a shank to each of a fixed arm and a movable arm pivotally connected to the fixed arm. In a spot welding gun provided opposite, a cylindrical bracket is fixedly intersected with the shank on the fixed arm side, and pins having a large diameter portion and a small diameter portion at both ends of the bracket are spring-loaded. The large-diameter portion is biased so as to be positioned outside the end surface of the bracket by a stopper, and is inserted so as to be able to advance and retreat, and can be disengaged from the pins at both ends of a back bar that abuts against the tip of the electrode tip on the fixed arm side. A connection plate having a hole is fixed, and a back bar is attached to the bracket via this connection plate so as to be detachable and floatable.

[0008]

With the above arrangement, the back bar can be attached to and detached from the bracket by one-touch operation and floating without any metal fatigue portion can be mounted by simply operating the pin with the fingertip.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1a denotes a fixed arm, and 1b denotes a movable arm rotatably connected to the fixed arm 1a via a pivot 2. These fixed arm 1a and movable arm 1b
Electrode tip 4 via shank 3a, 3b
a, 4b are provided facing each other.

According to the present invention, in the spot welding gun as described above, a cylindrical bracket 10 is fixedly mounted on the shank 3a on the fixed arm 1a side so as to cross.
The back bar 5 which comes into contact with the electrode tip 4a and which comes into contact with the pressure work W is detachably and floatably mounted.

The specific structure will be described below. The bracket 10 is cylindrical as shown in FIG. 3, and a pin 11 having a large-diameter portion 11 a and a small-diameter portion 11 b at both ends is stoppered by a spring 13 so that the large-diameter portion 11 a is outside the end face of the bracket 10. At 14, it is inserted so as to be able to move forward and backward by urging it so as to prevent it from falling off and to be positioned.

The back bar 5 has connecting plates 12 fixedly provided at both ends thereof. The connecting plate 12 has a hole 12a which is inserted with a gap into the large diameter portion 11a of the pin 11 and a diameter of the hole 12a which allows the small diameter portion 11b of the pin 11 to pass through the hole 12a. An opening 12b having a narrow width is provided.

Since the present invention has a structure as described above, when the back bar 5 is mounted on the bracket 10 via the connecting plate 12 as shown in FIGS. 12a is inserted into the large-diameter portion 11a of the pin 11 with a gap to allow floating, as shown in FIGS.

When the back bar 5 is detached from the bracket 10, the pin 11 is pressed with a fingertip as shown in FIG. 7 so that the small-diameter portion 11b is formed in the opening 12a of the hole 12a of the connecting plate 12 as shown in FIG. 12b.
Therefore, the connecting plate 12 is moved from the pin 11 to the opening 12b.
The back bar 5 can be detached from the pin 11 as shown in FIG. The same applies when the back bar 5 is mounted on the bracket 10.

[0015]

As described above, according to the present invention, a spot welding gun in which an electrode tip is provided to each of a fixed arm and a movable arm pivotally attached to the fixed arm via a shank. , A cylindrical bracket is fixed to the shank on the fixed arm side so as to cross, and pins having a large diameter portion and a small diameter portion are provided at both ends of the bracket so that the large diameter portion is outside the end surface of the bracket by a spring. A connecting plate having holes formed in both ends of a back bar that abuts against the tip of the electrode tip on the fixed arm side and that can be disengaged from the pin is fixedly urged so as to be positioned by a stopper. The back bar is attached to the bracket via this connection plate so that it can be attached to and detached from the bracket, and the back bar can be floated. Touch quickly can be detachably attached to the bracket by addition, since the coupling plate relative to the pin is engaged swingably, there is an advantage to enable floating without metal fatigue moiety.

[Brief description of the drawings]

FIG. 1 is a front view of the present invention.

FIG. 2 is an enlarged view of a main part of the present invention.

FIG. 3 is a sectional view of a portion A in FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 2;

FIG. 5 is a front view of the back bar in a floating state.

FIG. 6 is a sectional side view of FIG. 5;

FIG. 7 is an explanatory diagram of a detached state of a back bar.

FIG. 8 is a sectional view of the pin portion in the state of FIG. 7;

FIG. 9 is an explanatory view of the attachment / detachment procedure of the back bar.

FIG. 10 is a front view of a conventional spot welding gun having a back bar.

[Explanation of symbols]

 1a Fixed arm 1b Movable arm 2 Axis 3a Shank 3b Shank 4a Electrode tip 4b Electrode tip 5 Back bar 10 Bracket 11 Pin 11a Large diameter portion 11b Small diameter portion 12 Connection plate 12a Hole 12b Opening 13 Spring 14 Stopper

Claims (1)

(57) [Scope of request for utility model registration] In a spot welding gun provided with a fixed arm and a movable arm rotatably pivotally attached to the fixed arm with an electrode tip opposed thereto via a shank, a shank on the fixed arm side is provided. A cylindrical bracket is intersected and fixed, and pins having a large diameter portion and a small diameter portion at both ends of the bracket are urged by a spring so that the large diameter portion is positioned outside the end surface of the bracket by a stopper. A connecting plate having holes that can be engaged with and disengaged from the pins is fixedly provided at both ends of a back bar that abuts on the tip of the electrode tip on the fixed arm side, via the connecting plate. A spot welding gun, wherein a back bar is detachably mounted on the bracket so as to float.