JP2000061640A - Electrode tip of consumable electrode type arc welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an unstable phenomenon concerning a welding power supply from an electrode tip to an electrode wire, which occurs due to slight deformation or thickness of the electrode wire, or wear of the electrode tip in a consumable electrode type arc welding machine, and also to prolong the life of the electrode tip. SOLUTION: An electrode wire 10 is inserted and guided into a passage 21 in a cylindrical electrode tip 20 to which an electric power source is connected, while the inner face of the passage 21 and the electrode wire 10 are in electrical contact with each other in the device so structured, a forced contact means 30 is provided which increases a contact face pressure between the inner face of the passage and the electrode wire 10 by slightly bending the axial line of the passage 21 of the electrode tip 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a supply structure for supplying welding power from an electrode tip 20 to an electrode wire 10 in a consumable electrode type arc welding machine.

[0002]

2. Description of the Related Art Generally, in arc welding, as shown in the principle diagram of FIG. 2, a low-voltage, large-current discharge phenomenon is caused between an electrode wire 10 and a base material 1 to generate a large amount of heat locally generated in the discharge. Welding is realized by utilizing it. Also, the electrode wire 10
For this purpose, a dedicated electrode made of tungsten or the like is used. In addition, separately, there is also one in which a welding rod is supplied. In the case where the electrode wire itself constitutes an electrode, the electrode tip 20 (contact tube, or simply tip, made of a metal tube)
The electrode wire 10 is inserted and guided so as to come into contact with a holder (also referred to as a holder), and while the electrode wire 10 is consumed while receiving welding power through the electrode tip 20, the consumed amount is continuously replenished. It is a consumable electrode type.

In the consumable electrode type, however, the electrode wire is generally constructed so that it is released from the wire reel 2 in sequence and passes through a linear passage having a circular cross section provided in the electrode tip 20. That is, it is expected that the two will make electrical contact with each other while passing through and that the large current will be delivered and received stably. It is expected that the electrode wire wound around the reel 2 and subjected to substantially uniform plastic deformation will advance while maintaining a uniform contact with the wall surface of the straight passage, and will be stably supplied with electric power. However, the contact area and contact pressure between the electrode wire and the passage are sometimes unstable due to changes in the bending of the electrode wire, rigidity of the bend, wear of the passage, etc. Will become unstable and high quality stable welding may not be possible. Especially in the case of thin wires, this phenomenon tends to occur.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in a consumable electrode type arc welding machine, the welding power from the electrode tip 20 to the electrode wire 10 can be more stably supplied. And longer (longer life)
It is intended to provide an electrode tip of a consumable electrode type arc welding machine that can be supplied over the entire length.

[0005]

According to a first aspect of the present invention for solving the above-mentioned problems, the electrode wire 10 is guided through a passage 21 in a cylindrical electrode tip 20 to which a power source is connected. In an electrode tip of a consumable electrode type arc welder configured such that the inner surface of the passage 21 and the electrode wire 10 are in electrical contact, the passage 21 has a constant cross section and its axis is slightly curved. Thus, the electrode tip of the consumable electrode type arc welding machine is provided with the forced contact means 30 for increasing the contact surface pressure between the inner surface of the passage 21 and the electrode wire 10. According to the above invention, since the forced contact means 30 between the electrode tip 20 and the electrode wire 10 is provided, the consumable electrode type arc welding machine that can supply welding power more stably over a longer period (long life). It is possible to provide the above electrode tip.

According to a second aspect of the present invention, in the first aspect, the forced contact means 30 has a meandering passage 34 in which the axis of the passage 21 slightly meanders, and at the meandering portion, the electrode wire 10 and the passage are formed. 21 is an electrode tip of a consumable-electrode type arc welding machine which ensures a contact area with 21 and a contact surface pressure. According to the above invention, since the contact surface pressure and the contact area of the electrode wire 10 and the electrode tip 20 are ensured at the meandering portion of the meandering passage 34, the forcible contact means 30 is formed. A consumable electrode type arc welder that can supply electric power more stably over a longer period (long life) can be implemented.

According to a third aspect of the present invention, there is provided an electrode tip for a consumable electrode type arc welding machine according to the first or second aspect, wherein the entire metal tube having a straight axis is plastically deformed to slightly meander. is there. According to the present invention, the electrode tip can be easily provided. The invention according to claim 4 is the electrode chip body according to claim 2, wherein the electrode tip 20 has a U-shaped groove 35 having a width for inserting the electrode wire 10 and meandering in the depth direction, and the U-shape. An electrode tip for a consumable-electrode arc welding machine, comprising: a serpentine passage 34 constituted by an electrode tip lid 33 fitted in a groove 35 to form a serpentine passage 34 having a circular cross section. . According to the present invention, the cross section of the meandering passage 34 can be formed more accurately, and a consumable electrode type arc welder that can supply welding power more stably over a longer period (long life) can be implemented.

According to a fifth aspect of the invention, the electrode wire 1 is provided in the passage 21 in the cylindrical electrode chip 20 to which the power source is connected.
0 is inserted and guided, and the inner surface of the passage 21 and the electrode wire 1
In an electrode tip of a consumable electrode type arc welding machine configured to make electrical contact with 0, an electrode tip body 32 having a U-shaped groove 35 having a width for inserting the electrode wire 10 and meandering in the depth direction. And the electrode wire 10 passing through the U-shaped groove 35
Roller 3 that pushes in the direction of the meandering depth of the U-shaped groove 35.
7, and a spring mechanism 38 that applies a pressing force to the roller 37.
The electrode tip of the consumable electrode type arc welding machine is characterized in that the forcible contact means 30 is formed by the roller mechanism 36 constituted by. According to the present invention, due to the existence of the spring mechanism 38, the electrode wire 10 and the electrode tip 2 are
The contact with 0 can be performed more reliably.

According to a sixth aspect of the invention, the electrode wire 1 is provided in the passage 21 in the cylindrical electrode tip 20 to which the power source is connected.
0 is inserted and guided, and the inner surface of the passage 21 and the electrode wire 1
In the electrode tip of the consumable electrode type arc welding machine configured to make electrical contact with 0, a part of the feeding passage 21 for the electrode wire 10 has a fan-shaped cross section divided in the circumferential direction. 41 and a ring spring 42 for tightening the outer circumference of the fan-shaped sectioned piece 41 in cross section, and the outer peripheral surface of the electrode wire 10 and the inner peripheral surface of the fan-shaped sectioned section 41 are kept in close contact with each other so that the forced contact means 30 is It is an electrode tip of a consumable electrode type arc welder characterized by being formed. According to the present invention, the electrode wire 10 and the electrode tip 20 can be more reliably brought into contact with each other by the ring spring 42 that tightens the outer circumference of the fan-shaped divided piece 41 in cross section.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an electrode tip 20 of the present invention.
FIG. 3 is an explanatory view of a main part of a consumable electrode type arc welder having a.
The same parts as those in the welding machine principle diagram of FIG. 2 are denoted by the same reference numerals. As shown in FIG. 1, this electrode tip 20 has
It is a conductive tube having a tubular passage 21 whose inner diameter is larger than the maximum diameter of the electrode wire 10 to be used, and the axis of which is bent to form a meandering passage 34 by being bent into a waveform having a slight amplitude with respect to a straight line. . In this example, the amplitude of the wave is on the order of or less than the inner diameter of the tube. Further, as the material thereof, a metal tube, a conductive carbon tube or the like can be adopted. In the case of a metal tube, it can be easily manufactured by sandwiching it between appropriate rollers and bending it. Such an electrode tip 20 is housed in a cylindrical torch 4, and the torch 4
And the shield gas 8 is supplied between the electrode chip 20 and the
It is ejected from the tip of the torch 4. Then, the electrode wire 10 wound on the spool 2 is supplied into the electrode tip 20 via the feeding roll 6. And the electrode wire 1
0 is sequentially supplied from the tip of the tip to the base material 1 side while being pressed into contact with the bent portion of the wave of the electrode tip 20. The electrode chip 20 is connected to the positive side of the power source, and the negative side thereof is connected to the base material 1. While discharging from the tip of the electrode wire 10 to the base material 1, the electrode wire is consumed to form a molten pool of molten metal, and the molten pool is solidified to perform welding.

Next, FIG. 3 is a sectional view showing an electrode tip 20 having a meandering passage 34 as another example of the consumable electrode type arc welding machine of the present invention, and FIG. 4 is a sectional view taken along the line AA of FIG. FIG. Further, FIG. 5 is a sectional view showing an electrode tip 20 having a roller mechanism 36 as another example of the consumable electrode type arc welding machine of the present invention, and FIG. 6 is a sectional view taken along the line BB of FIG. 7 is a partially cutaway view showing an electrode tip 20 having a sectional fan-shaped divided piece 41 as still another example of the consumable electrode type arc welder of the present invention, and FIG. 8 is an arrow of the CC cross section of FIG. 7. It is a perspective view. FIG. 9 is a cross-sectional view showing a contact state between the conventional electrode tip 20 and the electrode wire 10. The electrode tip 20 shown in FIGS. 3 and 4 has a meandering passage 34 having a circular cross section. The meandering passage 34 has a U-shaped groove 35 that meanders in the depth direction.
And an electrode tip lid 33 that fits in the U-shaped groove 34 to form the meandering passage 34.

The electrode tip 20 shown in FIGS. 5 and 6 is composed of a U-shaped groove 35 that meanders in the depth direction, and a roller mechanism 36 that pushes the electrode wire 10 toward the depth of the meandering. In the roller mechanism 36, the roller 37 attached to the cross beam material causes the electrode wire 10 to move by the spring force of the spring mechanism 38.
It is configured to force to meander. In the electrode tip 20 shown in FIGS. 7 and 8, a part of the cylindrical electrode material in the longitudinal direction is cut off in a plane including the axial center to form a sectional fan-shaped divided piece 41.
And a ring spring 42 for tightening the outer diameter of the fan-shaped sectional piece 41
And, A ring spring groove 43 for accommodating the ring spring 42 is provided on the outer diameter part of the fan-shaped sectional piece 41. As described above, FIG. 2 is a bird's-eye view showing a general configuration of the consumable electrode type arc welder and its operating state.
FIG. 10 shows a contact state between the conventional electrode tip 20 and the electrode wire 10 and is a sectional view taken along the line DD in FIG.

Next, the operation of the welding machine having the electrode tip 20 of the present invention will be described. In each of the embodiments, positively providing the forced contact means 30 concentrated in a part of the electrode wire 10 in the longitudinal direction in the passage 21 for the electrode wire 10 of the electrode tip 20 has a function of stably supplying welding power. Is dramatically increased. Of course, it was not completely lacking in the prior art. As shown in FIGS. 9 and 10, the electrode wire 10 wound on the wire reel 10
Is sent to the passage 21 by the feed roll, the contact naturally occurs, and the required welding power is supplied to the electrode wire 10. However, if you can supply the required power,
From the viewpoint of workability, the length of the electrode tip 20 is shorter, and from the viewpoint of power supply performance, a more stable and long-life electrode tip 20 is expected.

Here, a little more detailed observation will be made. In this case, if the electrode wire 10 in the passage 21 is regarded as an arc-shaped beam as shown in FIG. 9, both ends of the beam are supported by the entrance and exit of the electrode tip 20, and the back surface in the supporting direction receives a distributed load. However,
When the electrode wire 10 is thin, the rigidity is insufficient and it is difficult to maintain the surface pressure. In addition, when it is thick and the rigidity works effectively, the contact condition is as follows:
From point contact to line and surface contact, and on the back side, line contact to surface contact. In any case, since the contact area at both ends is small, the main power supply depends on the surface pressure and the contact length on the back surface. That is, after the start of use, the power supply performance generally improves rapidly, but when the wear amount reaches the limit, the surface pressure cannot be maintained. The above is a case where it is assumed that the plastic deformation of the electrode electrode wire 10 by the wire reel has a uniform radius of curvature. In reality, power supply instability occurs earlier for a variety of reasons. In order to improve the power supply performance at least without increasing the length of the electrode tip 20, it is necessary to secure the contact area and the surface pressure more stably and positively than in the case of a straight path having a simple circular cross section. . In addition, the excessive contact surface pressure is drained, and the electrode tip 2
Zero wear needs to be reduced. If the concentrated forced contact means 30 having these functions is provided, the power supply performance of the consumable electrode type arc welder can be improved.

One way of intentionally constructing a more concentrated force contact means 30 as compared to the conventional straight passage of circular cross section is that the electrode tip 20 is placed in the passage 21 for feeding the electrode wire 10 to the electrode. The meandering passage 34 that causes the wire 10 to meander is provided. The concentrated forced contact means 30 can be provided at each reliable contact point due to the meandering. That is, an electrode chip body 32 having a U-shaped groove 35 that has a width that allows the electrode wire 10 to be inserted and that meanders in the depth direction is fitted to the width of the U-shaped groove 35, and the fitting portions meander with the same pitch. The electrode tip lid 33 having the above-mentioned structure forms a meandering passage 34 having a circular cross section. The meandering passage 34 forms a meandering means for causing the fed electrode wire 10 to meander, and maintains a stable contact surface pressure and a contact length with the electrode wire 10 to provide an excellent forcible contacting means 30. However, meandering passage 3
The projected shape of 4 in the feeding direction is generally an ellipse slightly collapsed in the depth direction, and it is necessary to make the thicker wire closer to a perfect circle. In any case, the difference between the major axis and the minor axis is very small. For optimal design, wire diameter, rigidity, radius of curvature of plastic deformation, meandering pitch of meandering passage, meandering width, surface roughness, feeding power, etc. There are worries that involve many factors. Experimental relative comparison is essential.

On the other hand, in the structure for pressing the meandering path by the spring mechanism 38 and the roller mechanism 36, it is not necessary to scrutinize the various conditions described above, and only the spring force can be appropriately selected based on common sense design. If so, it can exhibit excellent characteristics in practical use. That is, the roller 37 arranged in conformity with the meandering of the U-shaped groove 35 forces the electrode wire 10 to meander. Moreover, the roller mechanism 36 has less frictional resistance against the feeding of the electrode wire 10 and can easily realize a smooth feeding speed. Also, when the electrode wire 10 has a local bend,
The spring mechanism 38 does not absorb and generate excessive surface pressure. Therefore, compared to the conventional straight passage of circular cross section,
The contact surface pressure and the contact length between the meandering passage 34 and the electrode wire 10 are always maintained stable, and a stable function can be maintained for a much longer period.

Another method of constructing a more concentrated force contact means 30 as compared to the conventional straight passage having a circular cross section is as follows.
A part of the passage 21 having a circular cross section of the electrode tip 20 is provided with a sectional fan-shaped divided piece 41, which is divided in the circumferential direction. The inner surface of the sectional fan-shaped divided piece 41 and the outer peripheral surface of the electrode wire 10 are in close contact with each other. It is provided with the intensive force contact means 30 by keeping. The contact between the electrode tip 20 and the electrode wire 10 in the sectoral divided piece 41 is kept in surface contact from the beginning, and the contact area can be secured in advance over the entire circumference of the electrode wire 10 in advance. Therefore, the contact surface pressure can be significantly reduced. Therefore, the wear rate of the electrode tip 20 is low, and the wear allowance can be sufficiently prepared structurally. Further, the change in the contact state due to the wear is very small, and the function of the stable and concentrated forced contact means 30 can be maintained for a long time. That is, the problem of instability in power supply can be fundamentally solved.

In the embodiment of FIG. 7, a fan-shaped divided piece 41 in cross section is used.
Is provided in the middle of the electrode tip 20 in the longitudinal direction. Both ends of the electrode tip 20 can be fixed with their axes aligned, and they are robust against external forces. A spring groove 43 for the ring spring 42 is provided on the outer periphery of the fan-shaped sectional piece 41. The spring groove 43 imparts a flexible flexure to the sector-shaped divided piece 41 itself, and enhances close contact with the electrode wire 10. Further, the ring spring 42 is prevented from protruding into the inert gas passage on the outer periphery of the electrode tip 20. Of course, the ring spring 42 generates a contact surface pressure between the sector-shaped divided piece 41 in cross section and the electrode wire 10. However, even if the segmental fan-shaped divided piece 41 is considerably worn, the effect on the spring force is small, and readjustment from the initial adjustment value is almost unnecessary.

Although not shown, a fan-shaped cross-section segment 41 may be provided at the outlet end of the electrode tip 20 with the same structure as described above. In this case, the fan-shaped section 41 is
There is a possibility that a cantilever beam is formed and bending is likely to occur, and the supply position of the electrode wire 10 may be slightly unstable. But,
If a strainer for linearizing the electrode wire is provided immediately before the feeding roll, the position is stable, and there is an advantage that even the electrode wires 10 having different diameters can be used without problem in some cases. On the other hand, in this case, a taper screw may be screwed in place of the ring spring 42. The rigidity of the cantilever is increased, and the instability of the supply position can be eliminated. However, the automatic followability to the wear of the passage 21 is lost. Although,
Compared with the conventional straight passage having a rigid circular cross section, the effect of having the gap adjusting function is great.

[0020]

As described above, according to the first aspect of the invention, the passage 21 for feeding the electrode wire 10 of the electrode tip 20 is provided with the forced contact means 30 for contacting the electrode wire 10. This makes it possible to provide a consumable electrode type arc welder that can supply welding power more stably and for a longer period (long life). According to the second aspect of the present invention, in the first aspect, the electrode tip 20 is provided with the meandering passage 34 for meandering the electrode wire 10 in the passage 21 for feeding the electrode wire 10, and the electrode wire is provided at the meandering portion. Since the forcible contact means 30 that secures the contact area and the contact surface pressure between the No. 10 and the passage 21 is formed, consumable electrode type arc welding that can supply welding power more stably and for a longer period (long life). Machine can be provided.

The invention according to claim 3 is an electrode tip for a consumable electrode type arc welding machine, in which an entire metal tube having an axial straight line is plastically deformed to slightly meander. According to the present invention, the electrode tip can be easily provided. According to the invention described in claim 4, in the electrode chip body 32 according to claim 2,
The meandering passage 34 having a circular cross section by the electrode tip cover 33 and the electrode tip lid 33.
Since the meandering passage 34 of the electrode tip 20 is accurately formed, it is possible to provide a consumable electrode type arc welder that can supply welding power more stably and for a longer period (long life).

According to the invention of claim 5, an electrode tip body 32 having a U-shaped groove 35 meandering in the depth direction,
The roller mechanism 36, that is, the roller 37 that pushes the electrode wire 10 that advances through the U-shaped groove 35 toward the depth of the meandering of the U-shaped groove 35, and the spring mechanism 3 that applies a pressing force to the roller 37.
The roller mechanism 36 constituted by 8 and 8 forms the forcible contact means 30, and the forcible contact means 30 can be more effectively maintained, and the welding power is more stable and for a longer period (long life). A consumable electrode type arc welder that can be supplied can be provided. According to the invention as set forth in claim 6, the electrode chip 20 has a sectional fan-shaped divided piece 41 in which a portion of the electrode wire 10 feeding passage 21 is divided in the circumferential direction, and a sectional fan-shaped divided piece 41. And a ring spring 42 for tightening the outer periphery of the electrode wire 10, and by maintaining close contact between the outer peripheral surface of the electrode wire 10 and the inner peripheral surface of the fan-shaped sectional piece 41, it is possible to form the concentrated forced contact means 30. It is possible to provide a consumable electrode type arc welder that can supply welding power more stably and for a longer period (long life).

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional explanatory view of a welding machine having an electrode tip of the present invention.

FIG. 2 is a bird's-eye view showing the configuration and operating status of a commonly used consumable electrode type arc welder.

FIG. 3 is an electrode tip 2 having a meandering passage 34 of circular cross section.
FIG.

FIG. 4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a cross-sectional view of the electrode tip 20 having a meandering U-shaped groove 35 and a roller mechanism 36.

6 is a cross-sectional view taken along line BB of FIG.

FIG. 7 is a side sectional view showing an electrode chip 20 having a fan-shaped divided piece 41 in section.

8 is a cross-sectional view taken along the line CC of FIG.

FIG. 9 shows a conventional electrode tip 20 and electrode wire 10.
The sectional side view which shows the contact condition with.

10 is a cross-sectional view taken along the line DD of FIG.

[Explanation of symbols]

1 base material 2 spools 4 torch 5 welding power source 6 feeding rolls 7 Feed motor 8 Shield gas 10 electrode wire 20 electrode tip 21 passage 30 Forced contact means 32 electrode chip body 33 electrode tip lid 34 meandering passage 35 U-shaped groove 36 Roller mechanism 37 Roller 38 Spring mechanism 41 Sectional fan-shaped divided pieces 42 ring spring 43 spring groove 53 Inert gas passage

Claims (6)

[Claims] 1. A cylindrical electrode chip 20 to which a power source is connected.
In an electrode tip of a consumable electrode type arc welding machine configured such that an electrode wire 10 is inserted and guided in an inner passage 21 and the inner surface of the passage 21 and the electrode wire 10 are electrically contacted with each other. An electrode of a consumable electrode type arc welder provided with a forced contact means 30 for increasing the contact surface pressure between the inner surface of the passage 21 and the electrode wire 10 by having a constant cross section and slightly curving the axis thereof. Chips. 2. The forced contact means 30 according to claim 1, wherein the forced contact means 30 has a meandering passage 34 in which the axis of the passage 21 meanders slightly, and the contact area and contact area between the electrode wire 10 and the passage 21 at the meandering portion. Electrode tip of consumable electrode type arc welder designed to secure surface pressure. 3. The electrode tip of a consumable electrode type arc welder according to claim 1, wherein the metal tube having an axial straight line is plastically deformed to meander slightly. 4. The electrode tip body 3 according to claim 2, wherein the electrode tip 20 is provided with a U-shaped groove 35 having a width for inserting the electrode wire 10 and meandering in the depth direction.
Consumable electrode type arc welding, characterized in that it comprises a meandering passage 34 constituted by 2 and an electrode tip lid 33 fitted in the U-shaped groove 35 and forming a meandering passage 34 having a circular cross section. Machine electrode tip. 5. A cylindrical electrode chip 20 to which a power source is connected
In the electrode tip of the consumable electrode type arc welding machine configured so that the electrode wire 10 is inserted and guided through the passage 21 in the inside, and the inner surface of the passage 21 and the electrode wire 10 are electrically contacted with each other, U of the width to be inserted, meandering in the depth direction
An electrode tip body 32 having a U-shaped groove 35, a roller 37 for pushing the electrode wire 10 traveling in the U-shaped groove 35 in the direction of the meandering depth of the U-shaped groove 35, and a spring for applying a pressing force to the roller 37. An electrode tip for a consumable electrode type arc welding machine, characterized in that a forced contact means 30 is formed by a roller mechanism 36 constituted by a mechanism 38. 6. A cylindrical electrode chip 20 to which a power source is connected.
In the electrode tip of the consumable electrode type arc welding machine configured such that the electrode wire 10 is inserted and guided through the passage 21 in the inside and the inner surface of the passage 21 and the electrode wire 10 are electrically contacted with each other, the electrode tip 20 is The passage 2 is provided in a part of the feeding passage 21.
1 is provided with a cross-section fan-shaped divided piece 41 that is separated in the circumferential direction, and a ring spring 42 that tightens the outer periphery of the cross-section fan-shaped divided piece 41.
By maintaining close contact between the outer peripheral surface of the electrode wire 10 and the inner peripheral surface of the fan-shaped sectional piece 41, the forced contact means 30
An electrode tip for a consumable electrode type arc welder, which is characterized in that