阅读说明：本技术 焊接用焊嘴 (Welding tip for welding ) 是由 藤原润司 于 2018-11-26 设计创作，主要内容包括：焊接用焊嘴(1)包括：沿着轴心形成有焊丝插孔(10)的焊嘴主体(1a)、以及将焊丝(6)向位于焊丝插孔(10)的内表面的供电点(7)按压的板簧(4)。在焊嘴主体(1a)的顶端侧外周面形成有开口部(11)。板簧(4)的位于焊嘴主体(1a)的顶端侧的一端部为自由端,另一方面,板簧(4)另一端部被固定于焊嘴主体(1a)。开口部(11)具有收纳板簧(4)的第一开口部(11a)、以及与第一开口部(11a)连通且将焊接时的磨损粉末向外部排出的第二开口部(11b)。(A welding tip (1) is provided with: the welding tip comprises a welding tip main body (1a) with a welding wire insertion hole (10) formed along the axis, and a plate spring (4) for pressing a welding wire (6) to a power supply point (7) positioned on the inner surface of the welding wire insertion hole (10). An opening (11) is formed in the outer peripheral surface of the tip end side of the tip body (1 a). One end of the plate spring (4) located on the tip side of the tip main body (1a) is a free end, and the other end of the plate spring (4) is fixed to the tip main body (1 a). The opening (11) has a first opening (11a) for accommodating the plate spring (4), and a second opening (11b) which communicates with the first opening (11a) and discharges the wear powder during welding to the outside.)

1. A welding tip having a wire insertion hole formed along an axial center of the welding tip, a power feeding point provided on an inner peripheral surface of the wire insertion hole, and a wire insertion hole through which a wire passing through the wire insertion hole is fed from the power feeding point,

this welding tip for welding includes:

a nozzle body having the welding wire insertion hole, an

A pressing portion that presses the welding wire to bring the welding wire into contact with the power feeding point,

an opening is formed in the outer peripheral surface of the tip end side of the tip main body,

the pressing portion is housed in the opening portion, one end portion of the pressing portion located on a tip end side of the tip main body is a free end, and the other end portion of the pressing portion located on an opposite side to the one end portion is fixed to the tip main body,

the opening portion has:

a first opening portion for accommodating the pressing portion, an

And a second opening portion communicating with the first opening portion and discharging abrasion powder generated at the power feeding point during welding to the outside.

2. The welding tip according to claim 1,

the second opening portion is formed on a side closer to a tip end of the tip main body than the power feeding point.

3. The welding tip according to claim 1,

the plurality of second openings are formed in a state where the second openings are aligned with each other at a predetermined interval on both sides facing each other in the axial direction with respect to the power feeding point.

4. The welding tip according to claim 1,

the plurality of second opening portions are formed in the tip body so as to be aligned in the circumferential direction on both sides in the circumferential direction with respect to the power feeding point so as to open in a direction intersecting the pressing direction of the pressing portion.

5. The welding tip according to claim 1,

the plurality of second opening portions are formed in a state of being arranged in the circumferential direction of the tip body on both sides in the circumferential direction with respect to the power feeding point so as to be opened along the pressing direction of the pressing portion.

6. The welding tip according to any one of claims 1 to 5,

the distance between the feeding point and the tip of the wire is set to be longer as the wire diameter of the wire increases, and the upper limit of the distance is set so that the arc generated during welding is stable.

7. The welding tip according to any one of claims 1 to 6,

an insulator for electrically insulating the pressing portion from the tip main body is provided between the pressing portion and the tip main body.

8. The welding tip according to claim 7,

the insulator has a predetermined heat resistance and is formed of any one of ceramics, resin, and paper.

9. The welding tip according to any one of claims 1 to 8,

the pressing portion is a plate spring.

10. The welding tip according to any one of claims 1 to 9,

the contact point of the pressing part, which is abutted against the welding wire, is polygonal or planar.

11. The welding tip according to any one of claims 1 to 10,

the welding wire diameter of the welding wire is the same as the width of the contact of the pressing part and the welding wire in the diameter direction of the welding wire, or the welding wire diameter of the welding wire is smaller than the width of the contact in the diameter direction of the welding wire.

12. The welding tip as defined in any one of claims 1 to 11,

the welding tip further includes a power supply member that is separate from the tip main body and is provided detachably to the tip main body,

the power supply point is provided on the power supply member.

Technical Field

The present invention relates to a welding tip for supplying power to a welding wire as a consumable electrode.

Background

In arc welding using a consumable electrode, a welding wire is fed to a welding torch by a wire feeding device, and a welding current is supplied from a welding machine to the welding wire via a contact tip that is a welding tip provided at the tip of the welding torch. The contact tip is formed with a wire insertion hole for inserting a wire through the axial center, and the wire is fed from the tip of the contact tip to a predetermined position of a workpiece through the wire insertion hole to perform arc welding.

In the case of a standard wire to be wound around a winding wheel, the wire is bent by the winding. Therefore, when the wire insertion hole is enlarged due to wear of the tip caused by welding, the wire is not positioned in the wire insertion hole, and the contact area between the wire and the tip end portion of the welding tip is changed. This causes sparks to be generated between the welding wire and the wire insertion hole, thereby generating irregularities on the inner surface of the wire insertion hole. When such irregularities occur, the power supply efficiency is lowered, and re-ignition (explosion sound of the electrode) and sputtering (scattering film of the electrode) are likely to occur. Similarly, if the inner surface of the wire insertion hole is uneven, the frictional resistance of the wire moving in the wire insertion hole increases, and a desired wire feed amount cannot be obtained, resulting in poor welding. In order to avoid such a problem, patent document 1 discloses a structure in which a welding wire is reliably brought into contact with a contact tip.

As shown in fig. 8, a conventional contact tip 101 disclosed in patent document 1 is made of copper or an alloy of copper and chromium, and is formed with a wire insertion hole 106 through which a wire 105 is inserted. The wire insertion hole 106 has a large-diameter tapered hole 107 on the inlet side of the welding wire 105, the large-diameter tapered hole 107 is provided to easily guide the welding wire 105 into the contact tip 101, and the wire insertion hole 106 has an expanded tapered hole 108 on the outlet side of the welding wire 105, so that the welding wire 105 can be easily pulled away from the inner peripheral surface of the wire insertion hole 106 even if the welding wire 105 is welded.

Further, an upper end portion of the contact tip 101 is provided with a mounting portion 102 for mounting the contact tip 101 to an electrode of a welding torch, not shown, and a lower end portion of the contact tip 101 is provided with a conical welding-side tip portion 103. A screw thread 104 is formed at the mounting portion 102 so that the contact tip 101 and the electrode are screw-coupled together.

Wire 105 is wound around wire winding wheel 109, and wire 105 is guided from wire winding wheel 109 to wire insertion hole 106 by wire feed rollers 111, 111 driven to rotate by wire feed motor 110, and is supplied to expanded tapered hole 108 via tapered hole 107 in wire insertion hole 106.

An opening 112 is formed in contact tip 101 along wire insertion hole 106, and plate spring 113 is provided in opening 112. The plate spring 113 is provided in tension in the opening portion 112 in the following manner: the front claw 114 is embedded in the contact tip 101, the rear claw 115 is inserted into the recess 116 communicating with the opening 112, the central protrusion 117 protrudes into the wire insertion hole 106, and the central protrusion 117 of the plate spring 113 is biased to press the wire 105 against the inner surface of the wire insertion hole 106 with a constant force.

Patent document 1: japanese laid-open patent publication No. Hei 10-034341

Disclosure of Invention

Technical problems to be solved by the invention

However, in the contact tip 101 of the related art, since current flows in the plate spring 113 that presses the welding wire 105, sparks are generated between the central projection 117, which is the pressing portion of the plate spring 113, and the welding wire 105, and the wear easily progresses. In particular, the rear claw 115 of the plate spring 113 abutting on the tip end side end portion of the tip is inserted into and fixed to the recess 116 provided in the contact tip 101, and the radial width of the plate spring 113 is substantially equal to the radial width of the opening 112. Therefore, when the welding wire 105 moves up and down to generate abrasion powder of the welding wire 105, the abrasion powder is easily accumulated in the vicinity of the upper surface of the concave portion 116 by its own weight. The abrasion powder thus accumulated around the plate spring 105, particularly at the connection portion with the tip end side of the tip 101, hinders the movement of the plate spring 113. The pressing force of the plate spring 113 pressing the welding wire 105 is thereby reduced, and therefore, the power supply to the welding wire may be unstable, and the life of the contact tip 101 may be shortened.

The present invention has been made to solve the above problems. The purpose is to provide a welding tip which can discharge abrasion powder to the outside and improve the service life.

Technical solution for solving technical problem

In order to achieve the above object, a welding tip according to the present invention is a welding tip having a wire insertion hole formed along an axial center thereof, a power feeding point provided on an inner peripheral surface of the wire insertion hole, and a power fed from the power feeding point to a wire inserted through the wire insertion hole, the welding tip including: the welding tip main body is provided with the welding wire insertion hole and a pressing portion which presses the welding wire to enable the welding wire to be abutted against the power supply point. An opening is formed in an outer peripheral surface of the tip end side of the tip end main body, the pressing portion is accommodated in the opening, one end portion of the pressing portion located on the tip end side of the tip end main body is a free end, and the other end portion of the pressing portion located on the opposite side of the one end portion is fixed to the tip end main body. The opening portion has: and a second opening portion communicating with the first opening portion and discharging abrasion powder generated at the power feeding point during welding to the outside.

According to this configuration, the abrasion powder generated during welding can be discharged to the outside, and the movement of the pressing portion can be prevented from being hindered by the abrasion powder. Therefore, the pressing force of the pressing portion against the welding wire can be suppressed from decreasing, and the tip life can be improved.

The second opening may be formed on a side closer to the tip end of the tip main body than the power feeding point, and a plurality of the second openings may be formed in a state of being arranged in parallel with each other with a predetermined interval therebetween on both sides opposing each other in the axial direction with respect to the power feeding point.

According to the above configuration, particularly by providing the second opening portion on the side closer to the tip end of the tip main body than the power feeding point, the abrasion powder can be reliably discharged to the outside.

Further, the plurality of second opening portions may be formed so as to be aligned in the circumferential direction of the tip body on both sides in the circumferential direction with respect to the power feeding point so as to open in a direction intersecting the pressing direction of the pressing portion, or the plurality of second opening portions may be formed so as to be aligned in the circumferential direction with respect to the power feeding point on both sides in the circumferential direction with respect to the tip body so as to open in the pressing direction of the pressing portion.

According to the above configuration, particularly by providing the second opening at the substantially same height position as the power feeding point, the abrasion powder can be reliably discharged to the outside.

Preferably, the distance between the feeding point and the tip of the wire is set to be longer as the wire diameter of the wire increases, and the upper limit of the distance is set so that an arc generated during welding is stable.

According to this configuration, the joule heat at the tip portion of the welding wire can be adjusted to stabilize the arc generated during welding, and desired welding can be performed.

Preferably, an insulator for electrically insulating the pressing portion from the tip main body is provided between the pressing portion and the tip main body, and more preferably, the insulator has a predetermined heat resistance and is formed of any one of ceramic, resin, and paper.

According to this configuration, the welding wire can be reliably brought into contact with the feeding point, and the current flowing through the welding wire can be stabilized. Further, deterioration of the insulator due to heat generation during arc welding can be suppressed.

The pressing portion is preferably a plate spring, and a contact point of the pressing portion with the welding wire is more preferably polygonal or planar.

According to the above configuration, the welding wire can be reliably brought into contact with the feeding point, and the current flowing through the welding wire can be stabilized.

The welding wire diameter of the welding wire is the same as the width of the contact of the pressing part and the welding wire in the diameter direction of the welding wire, or the welding wire diameter of the welding wire is smaller than the width of the contact in the diameter direction of the welding wire.

According to this configuration, the pressing portion can reliably press the welding wire against the feeding point.

Preferably, the welding tip further includes a power supply member that is provided separately from the tip main body and is detachably attached to the tip main body, and the power supply member is provided with the power supply point.

According to this configuration, power can be reliably supplied to the welding wire from the power supply point provided in the power supply member, and the life of the tip main body can be increased by replacing the power supply member.

Effects of the invention

As described above, according to the present invention, the reduction in the pressing force on the welding wire can be suppressed, and the life of the welding tip can be improved.

Drawings

Fig. 1A is a side view of a welding tip according to a first embodiment of the present invention.

Fig. 1B is a bottom view of the welding tip.

FIG. 1C is a schematic cross-sectional view taken along line IC-IC of FIG. 1B.

FIG. 1D is a schematic cross-sectional view taken along line ID-ID of FIG. 1C.

FIG. 1E is a schematic cross-sectional view taken along line IE-IE of FIG. 1C.

Fig. 2 is a schematic cross-sectional view of a welding tip according to modification 1.

Fig. 3A is a side view of a welding tip according to modification 2.

Fig. 3B is a bottom view of the welding tip according to modification 2.

Fig. 3C is a schematic cross-sectional view taken along line IIIC-IIIC of fig. 3B.

Fig. 3D is a schematic cross-sectional view taken along line IIID-IIID of fig. 3C.

Fig. 4A is a side view of a welding tip according to a second embodiment of the present invention.

Fig. 4B is a bottom view of the welding tip.

Fig. 4C is a schematic cross-sectional view taken along line IVC-IVC of fig. 4B.

Fig. 4D is a schematic cross-sectional view taken along line IVD-IVD of fig. 4C.

Fig. 5A is a side view of a welding tip according to modification 3.

Fig. 5B is a bottom view of the welding tip.

Fig. 5C is a schematic cross-sectional view taken along line VC-VC of fig. 5B.

Fig. 5D is a schematic cross-sectional view taken along VD-VD line of fig. 5C.

Fig. 6 is a schematic cross-sectional view of a welding tip according to a third embodiment of the present invention.

Fig. 7 is a schematic cross-sectional view of a welding tip according to a fourth embodiment of the present invention.

Fig. 8 is a schematic sectional view showing a welding tip in the related art.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

(first embodiment)

[ Structure of welding tip ]

Fig. 1A shows a side view and fig. 1B shows a bottom view of the welding tip according to the present embodiment. In addition, fig. 1C shows a schematic cross-sectional view taken along the line IC-IC of fig. 1B, fig. 1D shows a schematic cross-sectional view taken along the line ID-ID of fig. 1C, and fig. 1E shows a schematic cross-sectional view taken along the line IE-IE of fig. 1C.

As shown in fig. 1A to 1E, the welding tip 1 includes a tip main body 1A, a plate spring (pressing portion) 4, and an opening portion 11. As shown in fig. 1C, the distance between the tip of the wire 6 and a feeding point described later is referred to as Ex, the distance between the feeding point 7 and the tip surface of the tip body 1a is referred to as Ex1, and the distance between the tip surface of the tip body and the tip of the wire 6 is referred to as Ex 3. Here, the distance Ex corresponds to the actual protruding length of the welding wire 6. The tip of the wire 6 corresponds to the welding point position at the time of arc welding. As can be seen from fig. 1C, the distance Ex is equal to the sum of the distance Ex1 and the distance Ex 3.

In the following description, the extending direction of the wire insertion hole 10 is sometimes referred to as the Z direction, the direction parallel to the direction in which the plate spring 4 presses the wire 6 is referred to as the X direction, and the direction orthogonal to both the X direction and the Z direction is sometimes referred to as the Y direction. The inlet side of the wire insertion hole 10 may be referred to as "upper side", and the outlet side of the wire insertion hole 10, that is, the tip side of the welding tip 1 may be referred to as "lower side".

The tip body 1a is made of copper or an alloy of copper and chromium, and is formed with a wire insertion hole 10 for passing the welding wire 6 through the axial center. The wire insertion hole 10 has: an upper tapered portion 10a whose diameter decreases from the inlet side of the welding wire 6, i.e., the upper end portion, toward the lower side; a straight portion 10b formed next to the upper tapered portion 10a and having a substantially constant diameter; and a lower tapered portion 10c having a diameter that increases toward the outlet side of the welding wire 6, i.e., the lower end, is formed next to the linear portion 10 b. By setting the upper tapered portion 10a to the above-described shape, the welding wire 6 can be easily guided to the wire insertion hole 10, and by setting the lower tapered portion 10c to the above-described shape, the welding wire 6 can be easily pulled away from the wire insertion hole 10 even if the welding wire 6 is welded in the vicinity of the outlet of the welding wire 6.

Further, an upper end portion of the tip main body 1a is provided with a mounting portion 8 for mounting the welding tip 1 to an electrode of a welding torch, not shown. The mounting portion 8 is formed with a thread 9 for securing the welding tip 1 and the electrode of the welding torch to each other by screwing. Further, when the welding wire 6 is brought into contact with a predetermined point (hereinafter referred to as a feeding point 7) located on the inner surface of the wire insertion hole 10, power is fed from the electrode of the welding torch to the welding wire 6 via the tip main body 1a, joule heat is generated in the welding wire 6, and an arc can be generated between the welding wire 6 and a workpiece, which is a welding target (not shown).

An opening 11 is formed in the outer peripheral surface of the tip end side, which is the lower side of the tip main body 1 a. The opening 11 is composed of a first opening 11a and a second opening 11b, the first opening 11a accommodating the plate spring 4, and the second opening 11b facing the first opening 11a with the welding wire 6 therebetween and communicating with the first opening 11 a. The second opening 11b is provided to discharge metal spatters generated when spark is generated between the welding wire 6 and the feeding point 7 during arc welding, abrasion powder of the welding wire 6 generated by friction with the plate spring 4 when the welding wire 6 is fed, and the like to the outside of the welding tip 1. In the following description, these metal droplets and abrasion powder of the welding wire 6 may be collectively referred to as "abrasion powder". In addition, "wear powder" also includes wear powder generated by friction of the plated portion of the welding wire 6.

As shown in fig. 1C, the upper end of the plate spring 4 is supported by the tip body 1a and fixed to the tip body 1a, and a second bent portion (contact point) 4b that abuts against the welding wire 6 is disposed in the first opening 11 a. The lower side of the plate spring 4, that is, the end portion on the tip end side of the tip main body 1a is located in the first opening 11a and is not connected to the tip main body 1 a. That is, the end of the plate spring 4 located on the tip end side of the tip main body 1a becomes a free end. As shown in fig. 1C and 1D, second openings 11b are formed in the outer peripheral surface of the tip end side of tip body 1a in a state of being spaced apart from each other by a predetermined interval in the vertical direction of power feeding point 7, that is, being spaced apart from each other by a predetermined interval on both sides facing in the axial direction of power feeding point 7. Further, as shown in fig. 1E, the tip main body 1a located between the second opening portions 11b is provided so as to surround the first opening portions 11a from three directions. The wire diameter of the wire 6 is configured to be the same as or smaller than the width of the second bent portion 4b of the plate spring 4 in the Y direction. The plate spring 4 can thereby reliably press the welding wire 6 against the feeding point 7. Further, as shown in fig. 1D, the width of the portion of the plate spring 4 supported by the tip main body 1a in the Y direction is wider than the width of the second bent portion 4b in the Y direction shown in fig. 1E, but the width of the plate spring 4 in the Y direction shown in fig. 1D may be the same as the width of the second bent portion 4b in the Y direction.

As shown in fig. 1D, the second opening 11b extends toward the tip end side outer circumferential surface of the tip end side of the tip main body 1a with a constant width W1, but may be formed in a tapered shape so that the width thereof becomes wider toward the outer circumferential surface. For example, the shape may be an R shape or a chamfered shape.

Preferably, the width of the second opening 11b in the Y direction is larger than the wire diameter of the wire 6. For example, in the present embodiment, when the wire diameter is Φ 1.2mm, the widths H1 and H2 of the second opening 11b in the Z direction are 1mm to 5mm, and the width W1 in the Y direction is 5mm to 9.2 mm. The width of the tip body 1a located between the second openings 11b, that is, the portion of the tip body 1a having the power feeding point 7 in the Z direction is about 3 to 5 mm. By setting the respective dimensions in this manner, even if the width of tip main body 1a located between second openings 11b is 5mm or less, power can be reliably supplied to welding wire 6. On the other hand, if the width is 3mm or less, the heat capacity of the portion becomes too small, and the welding tip 1 may be worn out early by repeated welding, thereby shortening the life of the welding tip. However, the above value can be changed as appropriate depending on the amount of current flowing through the welding wire 6, the material and size of the welding tip 1, and the like.

The plate spring 4 is a plate-like member made of a metal material such as iron or stainless steel, extends downward from a portion supported by the nozzle body 1a, and is bent at a first bent portion 4a so as to approach the welding wire. The plate spring 4 is bent so as to be separated from the welding wire 6 at a second bent portion 4b which is a contact portion with the welding wire 6, and a lower portion of the plate spring 4 from the first bent portion 4a has an L-shape. By bending the plate spring 4 in this manner, the second bent portion 4b is configured to press the contact of the welding wire 6 against the power feeding point 7 with a predetermined pressing force. Further, by forming the plate spring 4 as a member made of the above-described material, it is possible to suppress deformation of the plate spring 4 due to heat generated during arc welding, and to maintain the pressing force on the welding wire 6. When the plate spring 4 is made of a copper alloy such as phosphor bronze, the plate spring 4 is deformed by heat generated during arc welding, and the pressing force to the welding wire 6 is weakened or the plate spring 4 itself is easily worn. The plate spring 4 needs to have a predetermined thickness in order to exert the pressing force, and for example, in the present embodiment, the thickness of the plate spring 4 is set to about 0.2mm to 0.5 mm. However, the present invention is not particularly limited to this, and can be appropriately changed in accordance with the setting of the pressing force.

In addition, when the wire 6 is fed upward or downward, frictional resistance is generated between the wire 6 and the second bent portion 4 b. In order to reduce this resistance, for example, the bending amount of the second bent portion 4b is set to 1mm to 3mm, and the bending angle is set to 90 °. In order to prevent the plate spring 4 from contacting the tip main body 1a, the distance Ex1 between the feeding point 7 and the tip end surface of the tip main body 1a shown in fig. 1C is preferably about 2mm to 5 mm. However, this value is not particularly limited as long as the frictional resistance described above can be reduced, and it is sufficient that the second bent portion 4b does not become a sharp end. For example, the bending angle may be set to any angle between 60 ° and 120 °. The second bent portion 4b may have an arc shape.

Further, an insulator 5 is attached to a portion of the plate spring 4 supported by the tip main body 1 a. Openings 4c and 5a for allowing the bolt 3 to pass through are formed in the plate spring 4 and the insulator 5, respectively, but as described later, in order to avoid contact between the plate spring 4 and the bolt 3, the opening 4c formed in the plate spring 4 is formed to have a larger diameter than the bolt 3 so as to ensure a predetermined gap between the plate spring 4 and the bolt 3. On the other hand, the opening 5a formed in the insulator 5 is formed to have a smaller diameter than the opening 4c formed in the plate spring 4. In the opening 5a, the bolt 3 may be in contact with the insulator 5.

The insulator 5 is a sheet-like member made of ceramic, resin, paper, or the like, and has predetermined heat resistance. For example, it is preferably formed of a heat-resistant material having 200 ℃ or higher. When arc welding is performed, the temperature of the welding tip 1 may be close to 400 ℃. On the other hand, the temperature of the insulator 5 at the portion supporting the plate spring 4 is kept at about 200 ℃. This is because the tip body 1a is cooled during a period in which arc welding is not performed, such as when the welding torch is moved to a welding site or when a welding object is replaced. Therefore, the heat resistance of the insulator 5 may be set to about the above value. The insulator 5 needs to have a predetermined thickness in order to exhibit a predetermined insulating property, and is, for example, about 0.05mm to 0.2mm in the present embodiment. However, the material is not particularly limited thereto, and may be appropriately changed depending on the material of the insulator 5, the required dielectric breakdown voltage, and the like.

Further, by fitting the insulator 5 to the plate spring 4, electrical insulation between the plate spring 4 and each of the tip main body 1a and the welding wire 6 can be ensured. The reasons why the plate spring 4 is consumed by repeating arc welding are roughly divided into two. One is as follows: as described above, the mechanical consumption of the plate spring 4 by the feeding of the welding wire 6. The other one is as follows: during the power supply, the consumption caused by the arc between the welding wire 6 and the vicinity of the power supply point 7 occurs. The latter being the dominant drain. Therefore, by fitting the insulator 5 to the plate spring 4, the generation of the arc can be prevented, and the current does not flow in the plate spring 4 and generate heat. This allows the wire 6 to be pressed against the feeding point 7 with a predetermined pressing force, thereby performing desired arc welding. Further, the welding wire 6 can be reliably fed from the feeding point 7 located on the inner surface of the wire insertion hole 10 formed in the tip main body 1 a. Further, since the insulator 5 is attached to the plate spring 4, abrasion powder does not directly adhere to the plate spring 4, and the plate spring 4 and the welding wire 6 are not fixed to each other by the abrasion powder due to heat generation by a welding current. This enables the wire 6 to be fed at a desired speed, and the wire 6 to be pressed against the feeding point 7 to perform desired arc welding.

A recess 1b communicating with the opening 11 is formed on the tip end side of the tip main body 1a, a plate spring 4 is disposed on the bottom surface of the recess 1b, in this case, a surface parallel to the Z direction inside the tip main body 1a, an insulator 5 is attached to the plate spring 4, and the metal cover 2 having an opening is attached to the tip main body 1a from the outside of the recess 1 b. The metal bolts 3 inserted into the opening of the cover 2 and the opening 4c of the plate spring 4 are screwed to the tip main body 1a to fix the plate spring 4 to the tip main body 1 a.

The wire 6 is wound around a wire winding wheel, guided from the wire winding wheel to the wire insertion hole 10 by a wire feed roller driven and rotated by a wire feed motor, and fed to a welding point with a workpiece through the wire insertion hole 10, which is not shown.

[ Effect and the like ]

As described above, the welding tip 1 according to the present embodiment includes: a tip body 1a having a wire insertion hole 10 formed along an axial center; and a plate spring 4 which is a pressing portion that presses the welding wire 6 against the feeding point 7 located on the inner surface of the welding wire insertion hole 10. The welding wire 6 passes through the wire insertion hole 10, and power is supplied to the welding wire 6 from the power supply point 7. An opening 11 is formed in the outer peripheral surface of the tip end side of the tip main body 1a, and the opening 11 has a first opening 11a for accommodating the plate spring 4 and a second opening 11b communicating with the first opening 11a and discharging abrasion powder generated at the time of welding to the outside. The plate spring 4 is accommodated in the first opening 11a of the opening 11, one end portion of the plate spring 4 located on the tip end side of the tip main body 1a is a free end, and the other end portion of the plate spring 4 located on the opposite side to the one end portion is fixed to the tip main body 1 a.

By configuring welding tip 1 in this manner, welding wire 6 can be reliably brought into contact with feeding point 7, and stable feeding of power to welding wire 6 is enabled. Further, by discharging the abrasion powder to the outside from the outer peripheral surface on the tip side of the welding tip 1, it is possible to prevent the abrasion powder from adhering to the plate spring 4 and accumulating in the contact of the plate spring 4, the inside of the wire insertion hole 10, and the like. In particular, the lower end portion of the plate spring 4 accommodated in the first opening 11a, that is, the end portion on the tip end side of the tip main body 1a is a free end not fixed to the tip main body 1a, and there is no connecting portion contacting the lower end portions of the tip 101 and the plate spring 113 as disclosed in patent document 1, and therefore, even if abrasion powder falls by its own weight to the lower surface of the first opening 11a, the movement of the plate spring 4 is not hindered. This can maintain the pressing force of the plate spring 4 pressing the welding wire 6, and can improve the life of the welding tip 1. In addition, power can be stably supplied to the welding wire 6.

Further, since the second opening 11b is provided in the tip-side outer peripheral surface of the tip main body 1a, the tip portion of the tip main body 1a protects the opening 11 from an arc generated during welding. The plate spring 4 is thus not directly exposed to a high-temperature environment, and thermal degradation of the plate spring 4 can be prevented, thereby improving the life of the welding tip 1.

Further, the pressing portion is formed as the plate spring 4, so that the welding wire 6 can be reliably pressed against the feeding point 7. In addition, the installation cost and the manufacturing cost of the plate spring 4 as the pressing portion can be reduced. Further, in contrast to the conventional configuration disclosed in patent document 1, the power feeding state to the wire 6 can be stabilized. This can suppress the occurrence of irregularities on the inner surface of wire insertion hole 10, and can suppress the occurrence of flash back and spatter due to a decrease in power supply efficiency. In addition, the following welding defects can be suppressed: since the inner surface of the wire insertion hole 10 has irregularities, frictional resistance increases when the wire 6 is fed, and a desired wire feed amount is not obtained, resulting in poor welding.

The pressing portion may have another structure, for example, a structure including a coil spring and an insulating member, and the insulating member biased by the coil spring may press the welding wire 6 against the feeding point 7. However, when such a structure is adopted, the insulating member and the cover 2 need to be made of a ceramic material or the like, which increases the price.

Preferably, the wire diameter of the wire 6 is equal to or smaller than the width in the wire diameter direction, i.e., the width in the Y direction of the second bent portion (contact) 4b of the plate spring 4 in contact with the wire 6. The plate spring 4 can thereby reliably press the welding wire 6 against the feeding point 7.

Further, according to the present embodiment, the structure of the welding tip 1 is not complicated, and assembly and processing at the time of manufacturing can be easily performed, so that the welding tip 1 can be provided at low cost.

< modification 1>

Fig. 2 shows a schematic cross-sectional view of a welding tip according to this modification. The cross section shown in fig. 2 corresponds to the cross section shown in fig. 1C. In the present modification, the same reference numerals are given to the same parts as those of the first embodiment, and detailed description thereof is omitted. In addition, in the same manner as in the embodiment and the modification described later, the same portions as in the first embodiment are denoted by the same reference numerals as necessary, and detailed description thereof is omitted.

The configuration of the present modification is different from that of the first embodiment shown in fig. 1 in the shape of the second bent portion 4b of the leaf spring 4, which is the contact portion with the welding wire 6. Specifically, the configuration shown in fig. 1 differs from the configuration shown in fig. 1 in that the second bent portion 4b is bent at an angle of 90 °, whereas the configuration shown in fig. 2 is such that a portion 4e between the second bent portion 4b and the third bent portion 4d has a polygonal planar shape, and this portion 4e is a contact point between the leaf spring 4 and the welding wire 6.

By forming the contact point 4e of the plate spring 4, which contacts the welding wire 6, into the shape shown in fig. 2, the consumption of the plate spring 4 can be further reduced, and the life of the welding tip 1 can be improved. Since the pressing force applied to the welding wire 6 is determined by the rigidity of the plate spring 4, the pressing force itself does not change greatly if the bending angle, the material, the thickness, and the like of the plate spring 4 are the same. On the other hand, since the contact area between the plate spring 4 and the welding wire 6 is increased, the pressure per unit area applied to the welding wire 6 is decreased. Therefore, when the welding wire 6 is fed, the friction force generated between the welding wire 6 and the plate spring 4 is reduced, and the consumption of the plate spring 4 can be reduced. Further, since the power feeding point 7 also moves as the contact 4e of the plate spring 4 moves in the Z direction, the consumption range of the power feeding point 7 and thus the tip body 1a is expanded. This reduces the local consumption of the tip body 1a, and improves the life of the welding tip 1. In the present modification, the length of the contact 4e of the plate spring 4 in the Z direction is set to about 2mm to 5mm, but the present invention is not particularly limited thereto, and can be modified as appropriate.

Note that, when the contact 4e of the plate spring 4 moves in the Z direction along the welding wire 6, the output current supplied to the welding wire 6 also changes at the same time. However, if the current amount flowing through the welding wire 6 is viewed as a whole (for example, 80A to 350A), the current does not change much, and the arc welding is not greatly affected. In the conventional configuration, when the consumption of the welding tip 1 increases, the power feeding point 7 moves upward in the wire insertion hole 10, but the change in the amount of current in the present modification is as small as about 5 to 20A with respect to the change in the amount of current in this case. The contact 4e of the plate spring 4 may be planar or not polygonal.

< modification 2>

Fig. 3A shows a side view of the welding tip according to the present modification, and fig. 3B shows a bottom view of the welding tip. In addition, fig. 3C shows a schematic cross-sectional view taken along line IIIC-IIIC of fig. 3B, and fig. 3D shows a schematic cross-sectional view taken along line IIID-IIID of fig. 3C.

The configuration shown in the present modification is different from the configuration shown in the first embodiment in that a second opening 11b is provided at one position below the power feeding point 7, i.e., on the tip end side of the tip main body 1a with respect to the power feeding point 7. In the present modification, power feeding point 7 is located on the inner surface of wire insertion hole 10 and is in contact with wire 6 at the upper surface of second opening 11 b.

With such a configuration of the welding tip 1, abrasion powder can be discharged to the outside from the outer peripheral surface on the tip side of the welding tip 1, and adhesion and accumulation of abrasion powder to the contact (second bent portion) 4b of the plate spring 4 and the like can be prevented. This can maintain the pressing force of the plate spring 4 pressing the welding wire 6, and can improve the life of the welding tip 1. In addition, power can be stably supplied to the welding wire 6. In particular, since the feeding point 7 is no longer located on the opposite side of the contact point 4b of the plate spring 4 with the welding wire 6 interposed therebetween, abrasion powder is less likely to stay in the wire insertion hole 10, and the abrasion powder can be reliably discharged to the outside of the welding tip 1.

Further, in the configurations shown in modifications 1 and 2 and the first embodiment, by providing the second opening 11b on the side closer to the tip end of the tip main body 1a than the feeding point 7, the wear debris falling to the lower side can be reliably discharged to the outside. In the configuration described later, the second opening 11b is provided on the side closer to the tip end of the tip main body 1a than the feeding point 7, whereby the same effect can be obtained.

In the present modification, the width H5 of the second opening 11b in the X direction is set to be about 1mm to 5mm, and the width W1 in the Y direction is set to be larger than the wire diameter of the wire 6. Specifically, the width of the wire 6 is set to a value that is about 1mm to 2mm from the outer periphery thereof to the outside in the radial direction of the tip body 1 a. However, the above value can be changed as appropriate depending on the amount of current flowing through the welding wire 6, the material and size of the welding tip 1, and the like.

(second embodiment)

Fig. 4A shows a side view of the welding tip according to the present embodiment, and fig. 4B shows a bottom view of the welding tip. In addition, fig. 4C shows a schematic cross-sectional view taken along line IVC-IVC of fig. 4B, and fig. 4D shows a schematic cross-sectional view taken along line IVD-IVD of fig. 4C.

In the configuration shown in the present embodiment and the configuration shown in the first embodiment, the arrangement of the second openings 11b provided in two locations is different. Specifically, the configuration shown in the first embodiment differs from the configuration shown in the first embodiment in that a plurality of second openings 11b are formed in a state of being arranged side by side with a predetermined interval between both sides facing each other in the axial direction with respect to the power feeding point 7, whereas a plurality of second openings 11b are formed in a state of being arranged side by side in the circumferential direction of the tip main body 1a on both sides sandwiching the power feeding point 7 in a direction intersecting the pressing direction of the plate spring 4, in this case, in a manner of being opened in the Y direction.

As shown in fig. 4C and 4D, in the present embodiment, the second opening 11b is formed to extend in the Y direction with the feeding point 7 interposed therebetween, and the width H3 of the second opening 11b in the Z direction is set to be 1mm to 5mm above and below the feeding point 7. When the width of the portion of the nozzle body 1a where the feeding point 7 is located is W2 in the Y direction and the widths of the second openings 11b located on both sides thereof in the Y direction are W3, the width W2 is preferably made larger than the wire diameter of the wire 6 in order to ensure contact between the feeding point 7 and the wire 6. Specifically, the width of the wire 6 is set to a value that is about 0.5mm to 2mm from the outer periphery thereof to the outside in the radial direction of the tip body 1 a. If width W2 is increased by about 0.5mm from the outer periphery of welding wire 6 to the outside in the radial direction of tip body 1a, the contact area between welding wire 6 and feeding point 7 can be secured. When the width W2 is further widened, the heat capacity at the power feeding point 7 can be secured, and the consumption of the tip main body 1a can be reduced. Preferably, the width W3 is secured to be about 0.5mm to 2mm with respect to the width W2 on both sides in the Y direction. For example, when the wire diameter of the wire 6 is Φ 1.2mm, the width H3 of the second opening 11b in the Z direction is about 2mm to 10mm, and the secured width W3 is about 0.5mm to 2mm on both sides of the width W2 in the Y direction. The width L1 in the X direction is set to 4mm to 6 mm. However, the above value can be changed as appropriate depending on the amount of current flowing through the welding wire 6, the material and size of the welding tip 1, and the like.

By forming the second opening 11b in the above-described shape, abrasion powder generated during welding can be discharged to the outside of the welding tip 1, and the life of the welding tip 1 can be increased. In particular, by forming a plurality of second openings 11b in a state of being arranged in parallel in the circumferential direction of tip body 1a on both sides of feeding point 7 so as to open in the Y direction, metal spatter caused by spattering in the vicinity of feeding point 7 can be reliably discharged to the outside of welding tip 1. Further, since the second opening 11b is also formed on the tip end side of the tip main body 1a with respect to the power feeding point 7, the abrasion powder falling to the lower side can be reliably discharged to the outside.

The second opening 11b is formed to extend toward the tip end side outer peripheral surface of the tip end side of the tip main body 1a with a constant width L1, but may be formed in a tapered shape so that the width thereof becomes wider toward the outer peripheral surface, as in the first embodiment. For example, the shape may be an R shape or a chamfered shape.

< modification 3>

Fig. 5A shows a side view of the welding tip according to the present modification, and fig. 5B shows a bottom view of the welding tip. In addition, FIG. 5C shows a schematic cross-sectional view taken along line VC-VC of FIG. 5B, and FIG. 5D shows a schematic cross-sectional view taken along line VD-VD of FIG. 5C.

In the configuration shown in the present modification and the configuration shown in the second embodiment, the arrangement of the second openings 11b formed in two locations is different. Specifically, the configuration shown in the second embodiment differs from the configuration shown in the second embodiment in that a plurality of second openings 11b are formed in the circumferential direction of the tip body 1a so as to be aligned in the circumferential direction of the tip body 1a on both sides with respect to the circumferential direction of the power feeding point 7 so as to be opened in the Y direction which is the direction intersecting the pressing direction of the plate spring 4, and in that a plurality of second openings 11b are formed in the circumferential direction of the tip body 1a on both sides with respect to the circumferential direction of the power feeding point 7 so as to be opened in the X direction which is the pressing direction of the plate spring 4. The width H3 of the second opening 11b in the Z direction and the width W2 of the portion of the tip main body 1a where the power feeding point is located are the same as those in the second embodiment. The width W4 of the second opening 11b in the Y direction is the same value as the width W3 shown in the second embodiment. However, the above value can be changed as appropriate depending on the amount of current flowing through the welding wire 6, the material and size of the welding tip 1, and the like.

With such a configuration of the welding tip 1, abrasion powder can be discharged to the outside from the outer peripheral surface of the tip end side of the welding tip 1, and adhesion of abrasion powder to the contact point of the plate spring 4 and the like or accumulation of abrasion powder in the wire insertion hole 10 can be prevented. This can maintain the pressing force of the plate spring 4 against the welding wire 6, and improve the life of the welding tip 1. In addition, power can be stably supplied to the welding wire 6.

(third embodiment)

Fig. 6 is a schematic cross-sectional view of the welding tip according to the present embodiment. The cross section shown in fig. 6 corresponds to the cross section shown in fig. 1C.

In the configuration shown in the first embodiment and the configuration shown in the present embodiment, the distance between the power feeding point 7 and the tip end surface of the tip main body 1a is different, and the distance Ex2 in the present embodiment is longer than the distance Ex1 shown in the first embodiment.

For example, although the distance Ex1 is about 2mm to 5mm in the first embodiment, the distance Ex2 in the present embodiment is 5mm or more and 30mm or less. For example, when the wire diameter of the wire 6 is Φ 1.2mm and the distance Ex3 is 10mm or more and 15mm or less, it is preferable that the distance Ex2 is 10mm or more and 15mm or less and the distance Ex is 20mm or more and 25mm or less. When the actual wire protrusion length, i.e., the distance Ex, is shorter than 20mm, the joule heat amount becomes small, and the desired welding may not be performed. On the other hand, when the distance Ex is longer than 25mm, the joule heat amount becomes excessively large, the wire 6 is excessively melted, and the arc becomes unstable.

When the wire diameter of the wire 6 is Φ 1.4mm and the distance Ex3 is 10mm or more and 15mm or less, it is preferable that the distance Ex2 is 10mm or more and 15mm or less and the distance Ex is 25mm or more and 30mm or less. When the actual wire protrusion length, i.e., the distance Ex, is shorter than 25mm, the joule heat amount becomes small, and the desired welding may not be performed. On the other hand, when the distance Ex is longer than 30mm, the joule heat amount becomes excessively large, the wire 6 is excessively melted, and the arc becomes unstable.

By thus increasing the distance Ex2, the actual projection length of the welding wire 6, i.e., the distance Ex, can be increased. For example, the distance Ex2 is set so that the distance Ex2 becomes longer as the wire diameter of the wire 6 increases, while the upper limit of the distance Ex2 is set so that the arc generated during welding is stabilized, whereby the projection length, i.e., the distance Ex, can be set to an appropriate value. This makes it possible to cause joule heat generated in the welding wire 6 to fall within a predetermined range, stabilize an arc generated during welding, and perform desired welding. Further, since the amount of heat generated in the welding wire 6 is increased, for example, when the same current is applied to the welding wire 6, the wire feed speed can be increased, and it is possible to shorten the cycle time due to the increase in the welding speed and improve the welding quality due to the increase in the amount of molten metal.

However, the distance Ex2 is not particularly limited to this range, and can be appropriately changed according to the wire diameter of the welding wire 6, the distance between the tip surface of the tip end body 1a and the welding point, and the like.

(fourth embodiment)

Fig. 7 is a schematic cross-sectional view of the welding tip according to the present embodiment. The cross section shown in fig. 7 corresponds to the cross section shown in fig. 1C.

In the configuration shown in the first embodiment and the configuration shown in the present embodiment, a power feeding member 12 formed separately from the tip main body 1a is provided on the side opposite to the plate spring 4 across the welding wire 6, that is, on the same side as the power feeding point 7.

The power supply member 12 is a conductive member having a recess (not shown) extending in the Z direction on the inner surface, is detachably fitted into a notch 1c formed inside the tip body 1a, and is fastened and fixed to the tip body 1a by a metal bolt 3. In addition, the recess constitutes a part of the wire insertion hole 10. Specifically, a part of the linear portion 10b is constituted. Further, in the power feeding member 12, openings 12a communicating with the second opening 11b are formed in a state where both sides facing each other in the axial direction with respect to the power feeding point 7 are arranged in parallel with a predetermined interval.

As shown in the present embodiment, the power feeding member 12 is provided separately from the tip main body 1a and detachably to the tip main body 1a, so that a portion of a contact portion between the power feeding member 12 and the welding wire 6, which portion is pressed by the plate spring 4, becomes the power feeding point 7, and power can be fed to the welding wire 6. That is, by providing the power feeding point 7 on the power feeding member 12, consumption of the tip main body 1a can be prevented. In addition, since the power supply member 12 can be easily replaced, the replacement period of the tip main body 1a can be extended. This can improve the life of the welding tip 1. Further, by using a material having excellent wear resistance, for example, molybdenum, tungsten, or the like for the power supply member 12, the life of the welding tip 1 can be further improved. Further, since the power supply member 12 itself is small in size, an increase in cost of the welding tip 1 can be suppressed.

Note that the power supply member 12 shown in this embodiment can be applied to the configurations shown in the first to third embodiments including modifications 1 to 3, and in this case, the same effects as those of this embodiment can be obtained. Further, the present invention is not limited to this, and a new embodiment can be formed by combining the respective constituent elements described in the above embodiments.

Industrial applicability-

The welding tip of the present invention can discharge abrasion powder generated during welding to the outside and improve the service life, and therefore is particularly useful as a welding tip used in an automatic welding system such as a robot.

-description of symbols-

1 welding tip

1a welding tip body

2 cover

3 bolt

4 leaf spring (pressing part)

4a first bending part

4b second bending part (contact)

4c opening

4d third bending part

4e contact part (contact) with the welding wire 6

5 insulating body

6 welding wire

7 power supply point

8 mounting part

9 thread

10 welding wire jack

11 opening part

11a first opening part

11b second opening part

12 Power supply part

101 contact welding tip

102 mounting part

103 welding side tip end part

104 thread

105 welding wire

106 welding wire jack

109 welding wire winding wheel

110 welding wire feeding motor

111 welding wire feeding roller

112 opening part

113 plate spring

117 central protrusion