JP2018126745A - Tip structure of arc welder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tip structure of an arc welder which can effectively suppress sputter deposition onto an inner peripheral surface of a nozzle.SOLUTION: A tip structure of an arc welder 1 comprising a contact tip 7 which supplies electric power to a weldment wire 8 while holding the weldment wire 8, and a nozzle 2 which covers an outer periphery of the contact tip 7 and guides a shield gas 9 around the weldment wire 8. The tip structure comprises plural rectification projections 3 which are provided on at least one of an outer peripheral surface of the contact tip 7 and an inner peripheral surface of the nozzle 2 and are along a spiral orbit with an axis of the nozzle 2 as a center, and plural relief holes 4 which communicates the inside and the outside of the nozzle 2 and are along a spiral orbit with the afore-said axis as a center. Both of the rectification projection 3 and the relief hole 4 have a length less than one round of the spiral orbit.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a tip structure of an arc welder.

  An arc welding machine that automatically performs arc welding is used for manufacturing industrial products such as automobiles. The arc welder includes a contact tip and a nozzle at the tip. The contact tip is a member that holds the welding wire and supplies power to the welding wire. By supplying power from the contact tip, an arc is generated at the welding location and the welding wire is melted. The nozzle is a member that covers the outer periphery of the contact tip and guides a shielding gas (also called inert gas) around the welding wire. The shielding gas has a role of shielding the arc from the atmosphere and improving the quality of welding.

  Spatters in which molten metal scatters are generated at welding locations using an arc welder. Spatter accumulates on the inner periphery of the nozzle and obstructs the flow of shield gas. Therefore, it is necessary to periodically remove the spatter adhering to the inside of the nozzle, and there is a problem that the operation is complicated. As a technique for solving this problem, for example, Patent Document 1 discloses a technique of covering a tip of a nozzle with a cap having a plurality of holes.

Japanese Patent Laid-Open No. 10-328840

  According to the technique of Patent Document 1, although spatter adherence into the nozzle can be suppressed, it is unavoidable that spatter adheres to the cap. Therefore, there is a problem that the cap must be periodically replaced, and the cost of the replacement cap is increased. Further, in the configuration of Patent Document 1, if the cap hole is made small to suppress the intrusion of the spatter into the nozzle, the flow of the shield gas is inhibited, and if the cap hole is made large, the effect of suppressing the intrusion of the spatter. There is also a technical problem that cannot be sufficiently obtained.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a tip structure of an arc welder that can effectively suppress spatter deposition on the inner peripheral surface of a nozzle. .

The tip structure of the arc welder according to one aspect of the present invention is
A tip structure of an arc welding machine comprising: a contact tip that holds the welding wire and supplies power to the welding wire; and a nozzle that covers an outer periphery of the contact tip and guides a shielding gas around the welding wire;
A plurality of rectifying protrusions provided on at least one of the outer peripheral surface of the contact chip and the inner peripheral surface of the nozzle and along a spiral trajectory centered on the axis of the nozzle;
A plurality of relief holes that communicate with the inside and outside of the nozzle and that follow a spiral trajectory centered on the axis, and
The straightening protrusion and the escape hole both have a length less than one round of the spiral track.

  According to the said structure, it can suppress that a sputter | spatter accumulates inside a nozzle. This is because a spiral airflow can be generated in the shield gas by the rectifying protrusion provided in the nozzle, and a force directed outward in the radial direction of the spiral axis acts on the spatter, making it difficult for the spatter to jump into the nozzle. . In addition, even if spatter jumps into the nozzle, the spatter is repelled radially outward by the spiral gas flow of the shielding gas, and is discharged to the outside of the nozzle through the escape hole provided in the nozzle. It is difficult to deposit spatter inside.

  By generating a spiral airflow in the shield gas, the directivity of the shield gas along the axial direction of the nozzle is increased, and the shield gas can be reliably guided to the part where the arc is generated, so the arc is cut off from the atmosphere. Easy to do. In addition, since the directivity of the shield gas increases, the shield gas hardly leaks from the escape hole provided in the nozzle.

It is a schematic block diagram of the front-end | tip structure of the arc welder shown in Embodiment 1. It is a schematic longitudinal cross-sectional view of the tip structure of the arc welding machine shown in Embodiment 1. It is a schematic longitudinal cross-sectional view of the tip structure of the arc welder shown in Embodiment 2.

  Hereinafter, embodiments of a tip structure of an arc welder according to the present invention will be described with reference to the drawings.

<Embodiment 1>
The tip structure 1 of the arc welding machine of this embodiment shown in FIG. 1 holds the welding wire 8, covers the outer periphery of the contact tip 7 and feeds the welding wire 8, and shields the periphery of the welding wire 8. And a nozzle 2 for guiding the gas 9. One of the features of the tip structure 1 of the arc welder of this example is the structure of the nozzle 2. Hereinafter, the structure of the nozzle 2 will be mainly described. In the following description, the opening side of the nozzle 2 in the axial direction of the nozzle 2 (the side on which the shield gas 9 is injected) is referred to as the tip side, and the side opposite to the tip side is referred to as the root side.

≪Relief hole≫
As shown in FIGS. 1 and 2, the nozzle 2 has a plurality of escape holes 4 communicating with the inside and outside. The escape hole 4 functions as a discharge port for discharging spatter that has entered the nozzle 2 to the outside of the nozzle 2. The escape hole 4 is formed along a spiral trajectory (see a two-dot chain line) centered on the axis of the nozzle 2, and in this example, the first escape hole formed along the first spiral trajectory S1. 4A and a second escape hole 4B formed along the second spiral trajectory S2. The first spiral trajectory S1 and the second spiral trajectory S2 are arranged such that the second spiral trajectory S2 (first spiral trajectory S1) is arranged between the pitches of the first spiral trajectory S1 (second spiral trajectory S2). The first escape hole 4 </ b> A and the second escape hole 4 </ b> B are alternately arranged in the axial direction of the nozzle 2.

  The lengths of both escape holes 4A and 4B are less than one spiral track. That is, both escape holes 4A and 4B are less than one round in the circumferential direction when the nozzle 2 is viewed from the axial direction. Further, in the circumferential direction of the nozzle 2, the root side end of the first escape hole 4 </ b> A (second escape hole 4 </ b> B) and the tip side end of the second escape hole 4 </ b> B (first relief hole 4 </ b> A) are arranged in the circumferential direction. It overlaps.

≪Rectification protrusion≫
As shown in FIG. 2, a plurality of rectifying protrusions 3 are formed in the nozzle 2 to spiral the flow of the shield gas 9. In this example, the rectifying protrusion 3 is formed on the inner peripheral surface of the nozzle 2, but it may be formed on the outer peripheral surface of the contact chip 7. Of course, it may be formed on both the inner peripheral surface of the nozzle 2 and the outer peripheral surface of the contact chip 7. In FIG. 2 (the same applies to FIG. 3 to be described later), for convenience of explanation, the amount of protrusion of the rectifying protrusion 3 inward in the radial direction of the nozzle 2 is reduced, but the actual amount of protrusion is smaller than the illustrated example. large.

  The rectifying protrusion 3 includes a first rectifying protrusion 3A formed along the first spiral path S1 (FIG. 1), and a second rectifying protrusion 3B formed along the second spiral path S2 (FIG. 1). Can be divided into In this example, the first rectifying protrusion 3A is formed along the first escaping hole 4A on the tip side of the nozzle 2 with respect to the first escaping hole 4A, and the second rectifying protrusion 3B is formed on the second escaping hole 4B. Further, it is formed along the second escape hole 4 </ b> B on the tip side of the nozzle 2. That is, the first rectifying protrusions 3A and the second rectifying protrusions 3B are arranged so as to be alternately arranged in a spiral, and the length of the first rectifying protrusions 3A is the same as that of the first escape holes 4A, and the second rectifying protrusions 3B. Is the same as the length of the second escape hole 4B. Further, both the rectifying protrusions 3A and 3B have a length less than one round of the spiral trajectory, and in the circumferential direction of the nozzle 2, the root side end of the first rectifying protrusion 3A (second rectifying protrusion 3B) and the first end The tip end side end of the two rectifying protrusions 3B (first rectifying protrusion 3A) overlaps.

  By using the nozzle 2 having the rectifying protrusion 3, the shield gas 9 hits the rectifying protrusion 3 inside the nozzle 2, draws a spiral inside the nozzle 2, and is injected toward the tip of the nozzle 2. If the amount of protrusion of the rectifying protrusion 3 inward in the radial direction of the nozzle 2 is increased, a spiral airflow is easily generated, and the flow velocity is also likely to be increased. However, a gap is provided between the radially inner end of the rectifying protrusion 3 and the contact chip 7, and a path for the linear shield gas 9 extending in the axial direction of the contact chip 7 is provided. It is preferable.

≪Method of forming relief holes and rectifying protrusions≫
The escape hole 4 and the rectifying protrusion 3 of the nozzle 2 of this example can be formed as follows, for example. First, an unprocessed cylindrical nozzle 2 is prepared. A laser slit, a wire cut process, or the like is formed on the outer periphery of the nozzle 2 to form a horizontal slit along the spiral track and two vertical slits extending from both ends of the horizontal slit to the tip side of the nozzle 2. Then, the escape hole 4 and the rectifying protrusion 3 can be formed by bending the portion surrounded by the horizontal slit and the vertical slit into the nozzle 2.

≪Effect≫
According to the tip structure 1 of the arc welder described above, it is possible to suppress the deposition of spatter inside the nozzle 2. A spiral air flow can be generated in the shield gas 9 by the rectifying protrusion 3 provided in the nozzle 2, and a force directed outward in the radial direction of the spiral axis is applied to the spatter, so that the spatter hardly enters the nozzle 2. Because it becomes. Further, even if spatter jumps into the nozzle 2, the spatter is repelled radially outward of the nozzle 2 by the air current of the shield gas 9, and is discharged from the escape hole 4 provided in the nozzle 2 to the outside of the nozzle 2. Spatter is difficult to deposit inside the nozzle 2.

  Further, according to the tip structure 1 of the arc welder of this example, by generating a spiral air flow in the shield gas 9, the directivity of the shield gas 9 along the axial direction of the nozzle 2 is increased, and the arc is generated. Since the shield gas 9 can be reliably guided to the generated portion, it is easy to shield the arc from the atmosphere. Further, since the straight directivity of the shield gas 9 increases, the shield gas 9 hardly leaks from the escape hole 4 provided in the nozzle 2.

<Embodiment 2>
In the first embodiment, the configuration in which the escape hole 4 is formed in the rear portion of the rectifying protrusion 3 (on the side opposite to the tip of the nozzle 2) has been described. On the other hand, as shown in FIG. 3, an escape hole 4 may be formed in the front portion of the rectifying protrusion 3 (the tip side of the nozzle 2).

  The escape hole 4 and the rectifying protrusion 3 of the nozzle 2 of this example can be formed as follows, for example. First, an unprocessed cylindrical nozzle 2 is prepared. On the outer periphery of the nozzle 2, a horizontal slit along the spiral path and two vertical slits extending from both ends of the horizontal slit to the root side of the nozzle 2 are formed. Then, by bending the portion surrounded by the horizontal slit and the vertical slit into the nozzle 2, the escape hole 4 shown in FIG. 3 can be formed and the rectifying protrusion 3 can also be formed.

  Also with the configuration of this example, a spiral air flow can be generated in the shield gas 9 by the rectifying protrusion 3, and the intrusion of spatter into the nozzle 2 can be suppressed. Further, even if spatter jumps into the nozzle 2, the spatter is repelled outward in the radial direction of the nozzle 2 by the spiral air flow, and is easily discharged from the escape hole 4. As a result, it is possible to suppress the deposition of spatter inside the nozzle 2.

<Appendix>
Examples of the nozzle having the same effect as the tip structure of the arc welder according to the embodiment include the following configurations.

≪First nozzle≫
A nozzle that is attached to the tip of an arc welder and guides the shield gas to the weld,
A plurality of rectifying protrusions provided on an inner peripheral surface of the nozzle and along a spiral orbit centering on an axis of the nozzle;
A plurality of relief holes that communicate with the inside and outside of the nozzle and that follow a spiral trajectory centered on the axis, and
The rectifying protrusion and the escape hole are both nozzles having a length less than one round of the spiral track.

≪Second nozzle≫
A nozzle that is attached to the tip of an arc welder and guides the shield gas to the weld,
A plurality of escape holes along a spiral trajectory centered on the axis, and communicating with the inside and outside of the nozzle;
The escape hole is a nozzle having a length less than one round of the spiral track.
When using this nozzle, it is preferable to provide a plurality of rectifying protrusions along the spiral orbit around the nozzle axis on the outer peripheral surface of the contact tip of the arc welder to form a spiral air flow in the shield gas. .

DESCRIPTION OF SYMBOLS 1 Arc welding machine tip structure 2 Nozzle 3 Current flow projection 3A First current flow projection 3B Second current flow projection 4 Relief hole 4A First escape hole 4B Second escape hole 7 Contact tip 8 Welding wire 9 Shielding gas S1 First spiral orbit S2 Second spiral orbit

Claims (1)

A tip structure of an arc welding machine comprising: a contact tip that holds the welding wire and supplies power to the welding wire; and a nozzle that covers an outer periphery of the contact tip and guides a shielding gas around the welding wire;
A plurality of rectifying protrusions provided on at least one of the outer peripheral surface of the contact chip and the inner peripheral surface of the nozzle and along a spiral trajectory centered on the axis of the nozzle;
A plurality of relief holes that communicate with the inside and outside of the nozzle and that follow a spiral trajectory centered on the axis, and
Both of the straightening protrusion and the escape hole have a tip structure of an arc welding machine having a length of less than one spiral track.

Images