JPH0327734Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Industrial application field This invention is used when welding a joint that uses a stainless steel plate for the web (upright plate) and a mild steel plate for the flange (horizontal plate), so it requires a welding rod. This relates to a low-incline gravity welding machine whose tip is largely deflected toward the web.

B. Conventional technology When welding a dissimilar metal joint between stainless steel and mild steel, experiments have shown that the specific electrical resistance of mild steel is approximately one-fourth to one-fifth of that of stainless steel, so the welding current is naturally It tends to flow to the mild steel side, which has less resistance.

Therefore, since the arc was deflected toward the mild steel side, it was found that it was necessary to deflect the tip of the welding rod to a large extent toward the stainless steel side. As a result, when welding a joint using stainless steel for the web and mild steel for the flange, it was determined that the angle between the tip of the welding rod and the flange, that is, the appropriate aiming angle, is approximately 30 degrees or less. Judging from this, it has become clear that conventional commercially available gravity welding machines were manufactured for mild steel welding and cannot be used as is for horizontal fillet welding of stainless steel.

C. Means to solve the problem Therefore, this invention is a gravity welding machine for the purpose of welding dissimilar metal joints of stainless steel and mild steel as mentioned above. In a gravity welding machine that automatically performs welding while descending, a slider is attached to the guide bar by an internal roller, and a mainspring spring that can be freely expanded and contracted along the guide bar is attached to this slider. The tip is fixed to the lower end of the guide bar, and a spring-type automatic reversing device is attached to make the reversing shaft protrude downward in a direction perpendicular to the axis of the guide bar, and the welding holder is attached to the crank attached at right angles to this reversing shaft. is mounted so that it can move up and down on a rotating shaft, and is pressed downward by an elastic piece attached to the rotating shaft, so that the angle between the tip of the welding rod held by the welding holder and the flange surface of the workpiece during welding is approximately the same.
This is a low-inclination gravity welding machine installed so that the angle is 30 degrees or less. As a result, when the tip of the welding rod of the welding holder is aligned with the welding line of the joint, the welding machine is placed on the flange surface, and the power is turned on, as the welding rod wears out, the slider to which the welding holder is attached is guided by gravity and the tensile force of the mainspring spring. The bar is gradually lowered and welding continues automatically, and when it reaches the lower end plate, the lock lever of the slider's spring-type automatic reversing device comes into contact with the protrusion provided on the end plate, and the spring lock is released. , the welding holder is turned over and the tip of the remaining welding rod jumps up to cut the arc. During welding, the tip of the welding rod is held at a proper aiming angle, so that the weld forms the correct equilateral length and provides a healthy fillet bead without undercut or overlap at the bead toe. be.

D Embodiment An embodiment of the present invention will be described below based on the drawings. In a gravity welding machine that automatically performs welding while descending due to gravity, a slider 4 is attached to the slider 4 which is slidable by upper and lower rollers 5 in which the guide bar 1 is installed. Install a retractable mainspring spring 6 and fix its tip to the lower end of the guide bar 1.
Furthermore, a spring-type automatic reversing device 7 is installed inside, and its reversing shaft 8 projects downward in a direction perpendicular to the axis of the guide bar 1, and a crank 9 is mounted perpendicularly to the reversing shaft 8.
The welding holder 10 is attached to the rotary shaft 11 so as to be movable up and down, and is pressed downward by the elastic piece 12 attached to the rotary shaft 11, so that the tip of the welding rod R held by the welding holder 10 during welding It is installed so that the angle with the flange surface of the workpiece is approximately 30 degrees or less. In addition, the above elastic piece 12
Alternatively, a weight may be attached to the tip of the welding holder 10 to deflect the welding holder 10 downward. Further, in the drawing, 13 is a protrusion provided on the end plate leg 3, 14 is a lock lever of the spring type automatic reversing device 7, and 15 is a captire cord.

E Function The welding machine of the present invention configured as described above can be used to weld a joint in which the web W side is stainless steel and the flange F side is mild steel, by aligning the tip of the welding rod R with the weld line and attaching the end plate leg 3 to the end of the weld line. When the welding machine is placed on the flange surface and energized, as the welding rod wears out, the slider 4 with the welding holder 10 attached gradually moves down the guide bar 1 due to gravity and the tensile force of the mainspring spring 6 to automatically weld. Continue. When reaching the end plate leg 3 at the lower end, the protrusion 1 provided on the end plate
The lock lever 14 of the spring-type automatic reversing device 7 of the slider comes into contact with the slider 3 and the lock is released, and the welding holder 1
0 is reversed by the spring force, and the remaining tip of the welding rod R jumps up to cut the welding arc.

Note that this automatic reversing device 7 is a conventionally known device, so a detailed explanation will be omitted.
Furthermore, since the spiral spring 6 provided on the slider 4 is constructed with a low slope as a whole, the descending force is insufficient due to gravity alone, so it is used to supplement and assist the descending force.

F. Effects of the invention As explained above, the low-inclination gravity welding machine of the present invention makes it possible to weld joints between stainless steel and mild steel, which was impossible with conventional welding machines. Approximately the appropriate aiming angle
Since continuous welding is performed while maintaining an angle of 30 degrees or less, the weld part forms the correct isometric length for both materials, and a complete weld is automatically performed that provides a healthy fillet bead without undercut or overlap at the bead toe. It is effective in achieving the desired results.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a perspective view showing the state of use, Fig. 2 is a plan view with the upper part of the slider cut away to show the main parts of the invention, and Fig. 3 is an end plate of the slider. It is a partially cutaway rear view of a state where it is inverted and in contact with a leg. 1... Guide bar, 2... Support leg, 3... End plate leg, 4... Slider, 5... Roller, 6... Spring spring, 7... Spring type automatic reversing device, 8... Reversing shaft, 9...Crank, 10...Welding holder, 1
1... Rotating shaft, 12... Elastic piece, 13... Protrusion,
14... Lock lever, 15... Captive tire cord, R... Welding rod, W... Web side, F... Flange side.

Claims (1)

[Scope of utility model registration request] The guide bar 1 is supported at an angle by attaching the upper end of the guide bar 1 to the support leg 2 and the lower end to the end plate leg 3.
In a gravity welding machine that automatically performs welding while descending due to gravity along A mainspring spring 6 is provided, and its tip is fixed to the lower end of the guide bar 1. Furthermore, a spring-type automatic reversing device 7 is installed inside the slider 4, and its reversing shaft 8 is set in a direction perpendicular to the axis of the guide bar 1. A welding holder 10 is attached to a crank 9 that projects downward and is mounted at right angles to the reversing shaft 8 so as to be movable up and down by a rotating shaft 11, and is pressed downward by an elastic piece 12 attached to the rotating shaft 11. A low-incline gravity welding machine characterized in that the welding rod R held by the welding holder 10 is mounted so that the angle formed by the tip of the welding rod R with the flange surface of the workpiece is approximately 30 degrees or less during welding.