JP2902571B2 - Weld fume suction removal method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding fume removing method suitable for removing harmful fume by automatic welding using a robot.

[0002]

2. Description of the Related Art As a means for collecting and removing harmful welding fumes, a welding apparatus provided with a local exhaust device for exhausting the entire welded portion and a welding fume suction torch having a fume suction port provided in the welding torch itself. Kuniaki 51-20305
JP-A-5-138360, Japanese Patent Application No. 6-07356.
No. 0) and an apparatus for collecting dust by providing a hood on a welding robot (Japanese Utility Model Publication No. 7-13908).

[0003] In a welding operation by a welding robot and various automatic welding devices, welding conditions that are difficult and difficult to apply by conventional manual operations, for example, high current (300 A or more).
In addition, welding conditions for a long time are often employed, so that a large amount of fume is generated and a range in which the fume is dispersed increases.

FIG. 7 is a schematic view showing a bead-on-plate welding (thin plate welding) method. 7A is a diagram viewed from a direction orthogonal to the welding line, and FIG.
FIG. 3 is a diagram viewed from a direction orthogonal to FIG. Plate to be welded (thin plate) 1
A welding torch 2 is disposed above the welding torch, and a welding wire 3 is fed from the welding torch 2, and the welding wire 3 and the plate 1 to be welded are fed.
An arc 4 is generated between. A welding bead 5 is formed behind the welding direction. In this bead-on-plate weld fume is discrete in the region of the width W ₁ in either direction perpendicular weld line direction and thereto.

FIG. 8 is a schematic view showing a fillet welding method. A standing plate 7 is vertically arranged on the horizontal plate 6, and a welding torch 2 is attached to the corner where the horizontal plate 6 and the standing plate 7 intersect by about 4 mm.
A fillet welded joint is formed by the welding wire 3 and arranged at an angle of 5 °. In this case, fumes is regulated in the vertical plate 7 tends to flow in the weld line direction along the corner portion, thus, the discrete regions of the fumes is to have a width of W ₂ in the weld line direction.

FIG. 9 is a schematic view showing a butt welding method. The welded plates 8 and 9 are butted by forming a V-shaped groove at their butting ends. A backing metal 10 that is superimposed on the bottom surfaces of the plates 8 and 9 to be welded is disposed at the groove bottom. A welding torch 2 is inserted into the groove, an arc 4 is generated by a welding wire 3 sent out from the welding torch 2, and the groove is filled with a weld metal. In this butt welding, further spread more in the weld line direction fume discrete regions, fumes discrete in the region of the width W _3.

FIG. 10 is a graph showing the discrete width of the fume flow for each of these welding conditions. A on the horizontal axis represents the case of the bead-on-plate welding shown in FIG. 7, B represents the case of the fillet welding of FIG. 8, and C represents the case of the butt welding of FIG. As is clear from FIG. 10, the discrete width of the fume flow differs between the high current and the low current, and increases as the current increases. Further, the discrete width of the fume flow increases as fillet welding and butt welding are performed.

FIG. 11 shows a method of sucking and removing fumes at the time of butt welding by using the welding torch with the suction nozzle. The torch 11 with a fume suction nozzle has a double pipe structure, and a suction port 12 communicating with a gap between the outer pipe and the inner pipe.
, The air near the weld is sucked, the welding wire 3 is fed through the inner pipe, and the shielding gas is ejected.

[0009]

However, when collecting fumes dispersed in a wide area as described above, in the conventional local exhaust system, the fume collection hood has to be set apart from its source. Therefore, not only large-scale and expensive equipment is required, but also when the shape of the work to be welded is complicated, the fume collection hood cannot be placed at an appropriate position in terms of fume suction efficiency. At the time of installation and removal at a location, there were problems such as the hood becoming an obstacle.

Further, as shown in FIG. 11, when welding is performed by a torch 11 with a fume suction nozzle, a gas flow in which a shielding gas and fume are mixed is indicated near the tip of the welding torch as indicated by reference numeral 13. A gas stream 16 that is present and separate from it as fumes are present. When fumes are to be sucked through the suction port 12, in the direction along the welding line, an area indicated by reference numeral 14 is an area where the fume can be sucked and captured without hindering the shielding property. The region indicated by is a fume capturing region when the suction force is enhanced for fume capturing. In this region 14, even the shield gas is not sucked by the suction nozzle, and the shielding property is not hindered. However, the fume suction force is weak and the fume cannot be sufficiently sucked. on the other hand,
When the fume suction force is increased, the region 15 is sucked, so that the gas flow 13 containing the shielding gas is sucked, and the shielding property is impaired. In each of these cases,
The fume gas flow 16 has a portion that is separated without being sucked into the suction port 12. Further, in the direction orthogonal to the welding line, the flow of the shield gas is regulated by the groove surface and approaches the suction port 12, and there is a drawback that the shield gas is excessively sucked by the suction port 12.

Further, as disclosed in Japanese Utility Model Publication No. Hei 7-13908, although the above problem is partially solved by providing a welding robot with a hood, this technique can also be used to directly mount a welding torch head. It is not applicable when the welding fume does not rise directly above the welding torch. For example, it is not suitable for a welding posture other than a downward posture, that is, a welding posture of a lateral posture or an upward posture, and is difficult to apply to a robot welding operation that often takes such a posture.
There is a disadvantage that versatility is poor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a welding fume suction removing method capable of removing suction fumes efficiently and reliably in automatic welding using a robot. Aim.

[0013]

According to the present invention, there is provided a method for sucking and removing welding fume, comprising: disposing a welding torch and a suction nozzle having a suction port for sucking welding fume along a welding line; A welding fume that supplies a shielding gas and welds by an arc generated between a welding wire and a workpiece to be fed through a welding torch, and sucks fume-containing air from a welding portion by the suction nozzle. In the suction removing method, a flexible and electrically insulating insulating member is detachably attached to the suction nozzle, and the suction air volume of the suction nozzle is 0.2.
m ³ / min or more and the welding torch and suction nozzle
And at least 30 mm apart from the

[0014]

According to the present invention, a welding torch and a suction nozzle are arranged along a welding line, and fumes dispersed in a welding line direction from the tip of the welding torch are sucked by a suction nozzle during fillet welding or butt welding. And remove. In the horizontal fillet and butt welding, as described above, the generated fume is dispersed mainly in two directions along the groove or the like and flows out. For this reason, fumes can be reliably sucked by arranging suction nozzles on both sides of the welding torch in the welding line direction and performing suction. In this case, the fume suction nozzle is inserted as deep as possible. That is, the fume is suctioned by bringing the tip of the fume suction nozzle as close as possible to the welded portion that is the fume generation source where fume is generated. As a result, fumes can be efficiently removed by suction.

Thus, when the suction nozzle is inserted close to the welding line in order to approach the welded portion, the operation of the welding robot or the like causes the suction nozzle to come into contact with the material to be welded, thereby causing the suction nozzle to contact the workpiece. In some cases, conduction to the material to be welded may occur. However, in the present invention, since the electrically insulating member is provided at the tip or middle of the suction nozzle, even if the tip of the suction nozzle contacts the workpiece, the robot may stop operating. Absent. Also,
Since the insulating member has flexibility, even if the suction nozzle collides with the material to be welded by the movement of the robot, the insulating member does not break.

Thus, according to the present invention, in gas shielded arc welding of a consumable electrode wire feeding type,
Multiple suction nozzles are arranged at a sufficient distance from the torch so as not to disturb the shield state of the arc, and fumes can be removed by suction, and fumes can be captured with high efficiency by using as little suction air flow as possible. it can.

[0017]

Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing a first embodiment of the present invention. In FIG. 1, the same components as those in FIG. 9 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the present embodiment, two fume suction nozzles 20 are arranged on the welding line so as to sandwich the welding torch 2 that sends out the welding wire 3 and ejects the shielding gas. The fume suction nozzle 20 is connected to an appropriate exhaust device, and the exhaust device sucks the inside of the suction nozzle 20 to suck the fume gas flow 16 from the suction port at the tip (lower end) of the suction nozzle 20.

A flexible pipe-shaped insulating member 21 is detachably attached to the tip of the fume suction nozzle 20. The tip of the insulating member 21 functions as a suction port. This insulating member 21 can be formed of, for example, silicon rubber.

The suction nozzle 20 sucks the shield gas flow to prevent the shielding performance from being impaired.
, And arranged at a position interposed on the stream line of the fume gas flow 16.

In this embodiment, since the suction nozzle 20 is provided separately from the welding torch 2, this suction nozzle 20
Can be effectively arranged at the site where the fume gas flow is collected. For example, in the case of butt welding, the fume gas flow 16 spreads along the welding line, but in the present embodiment, the suction nozzle 20 can be arranged at a position where the fume gas flow 16 flows, and high efficiency is achieved. Fume can be sucked. An appropriate arrangement position of such a suction nozzle is as follows.
It depends on the length of the wire protruding, the flow rate of the shielding gas, welding conditions (current and voltage), and the suction air flow from the suction port. However, if the practical lower limit suction air flow is about 0.2 m ³ / min, the welding current will be lower. Under general butt welding conditions of about 500 A or less, the suction nozzle 20 is located at a distance from the welding torch 2 such that the distances L _l and L _t are 30 mm or more.

Further, since the two suction nozzles 20 are arranged along the welding line so as to sandwich the welding torch 2, a large amount of fume generated in the case of high current welding such as fillet welding and butt welding is reduced. It is possible to efficiently remove by suction.

Further, in this embodiment, the suction nozzle 2
Insulation member 2 having flexibility and electrical insulation at the tip of
1 is detachably provided on the suction nozzle body. The insulating member 21 prevents the operation of the robot from being stopped.
That is, in order to prevent the welding robot and the automatic welding device from being damaged by the contact with the workpiece to be welded, the welding robot and the automatic welding device electrically connect the welding torch with the workpiece to be welded. In general, it is provided with a function of detecting an alarm, issuing an alarm, stopping the operation, and the like. In the present invention, since the fume suction nozzle is provided outside the welding torch, the welding work and the welding device are more likely to come into contact with each other than when the torch is used alone. For this reason, when the suction nozzle is made of metal and has high rigidity, the suction nozzle comes into contact with the work, and the robot or the automatic welding device frequently issues an alarm or stops operation. On the other hand, by disposing the insulating member 21 at the tip of the suction nozzle 20 as in the present embodiment, it is possible to prevent the welding robot and the automatic welding device from stopping operation. In these robot devices,
It is necessary to clean the tip and inside of the welding shield nozzle by mechanical spatter removal cleaning method, etc.
By forming the suction nozzle tip with the insulating member 21 having flexibility, contact and damage between the cleaning device and the suction nozzle tip can also be prevented.

The material of the insulating member 21 at the tip of the nozzle only needs to have flexibility and electrical insulation for the above-mentioned purpose, and more preferably, it has heat resistance because it is close to the arc generating point. Is preferably higher. Further, it is preferable that the inner surface of the insulating member is relatively smooth and the pressure loss due to suction is small. Therefore, it is preferable to use, for example, a silicone rubber sleeve, a special ceramic fiber sleeve, or an aramid fiber sleeve as the insulating member 21. .

FIG. 2 is a schematic diagram showing a second embodiment of the present invention. In the present embodiment, the tip surface of the insulating member attached to the tip of the suction nozzle 20 is formed so as to be inclined with respect to the axial direction, as if the tip portion of the insulating member was cut off at the inclined surface. The inclined surface is formed at a position where it is hidden by the welding torch 2 when viewed from a point where an arc 4 is generated between the welding wire 3 delivered from the welding torch 2 and the workpiece. That is, as shown by the two-dot chain line in the figure, when a tangent line that contacts the outer edge of the welding torch 2 is drawn from the point where the arc 4 is generated, the area between the tangent lines is blocked from arc light. The suction nozzle 20 and the insulating member 22 at the tip of the suction nozzle 20 are located in the arc light blocking area, and
The lower surface of the insulating member 22 is formed so as to be inclined so that the suction port at the lower end of the insulating member approaches the welding line as much as possible.

Thus, by disposing the insulating member 22 at the tip of the suction nozzle in the space where the arc light is blocked, the insulating member 22 is directly exposed to intense arc radiation, receives radiant heat, spatters, and the like. Exposure is prevented and its durability can be increased. On the other hand, when the insulating member 22 is directly exposed to arc light or the like, the life of the silicon rubber is reduced by half in the case of silicon rubber.

FIG. 3 is a schematic diagram showing a third embodiment of the present invention. In the present embodiment, the insulating member 23 of the suction nozzle 20 is provided at the middle of the suction nozzle 20 without providing the insulating member 23 at the front end thereof. A tip member 24 made of the same material as the pipe is provided. The tip member 24 can be formed of a metal sleeve of copper or the like or a heat-resistant ceramic sleeve (alumina-silica type) or the like.
It is resistant to heat, ultraviolet rays, etc., and its life can be greatly improved.

For this reason, the tip member 24 can be arranged in a region exposed to the arc light. Therefore, the tip of the nozzle is located near the welded portion, which is also near the arc 4, to improve the fume suction efficiency. Can be improved. Thus, also in the present embodiment, the insulating member 23 is located in a region shielded from arc light (a region between two-dot chain lines in the figure).

FIG. 4 is a view showing a concrete example of the installation state of the welding torch and the suction nozzle of the embodiment shown in FIG. As shown in FIG. 4, the welding torch 2 has a torch body 31 fixed to a fixing member 30, and a shield nozzle 32 for ejecting a shielding gas at a tip end of the torch body 31.
Is provided. The fixing member 30 includes the suction nozzle 2
The welding torch and the suction nozzle are attached to the welding robot by the fixing member 30. These welding torch 2 and suction nozzle 2
Numerals 0 are located on the same plane, and are bent and extended from the fixing member 30 over the entire plane.

FIG. 5 is a view showing a specific example of the installation state of the welding torch and the suction nozzle. In FIG. 5, the welding torch 2 and the suction nozzle 20 and the fixing member 30 are located on the same plane, and the welding torch 2 and the suction nozzle 2
Numeral 0 is similarly bent and extended from the fixing member 30 on this plane.

FIG. 6 is a view showing a state in which the welding torch and the suction nozzle shown in FIG. 4 or FIG. 5 are attached to the arm 41 of the welding robot 40. By fixing the fixing member 30 to the tip of the arm 41, the welding torch 2 and the suction nozzle 20 are installed. A suction duct 42 is connected to the suction nozzle 20, and the suction duct 42 is connected to a duct 46 via a branch pipe 45. This duct 46 is connected to a fume collection device 52. As a result, the fume sucked in both ducts 42 joins the duct 46 and is collected by the fume collecting device 52 via the duct 46. On the other hand, a torch cable 43 is connected to the welding torch 2, and the torch cable 43 is connected to a wire feeding device 44. A gas hose 47 and a power supply line 50 are connected to the wire feeding device 44. The shielding gas is sent from the gas cylinder 53 to the wire feeding device 44 via the gas hose 47, and the welding wire is fed to the welding torch 2 via the torch cable 43 by the wire feeding device 44. The shield gas flows through the gas hose 47, and the shield gas is supplied to the welding torch 2 via the gas hose 47 and the torch cable 43. The power supply line 50, the duct 46, and the gas hose 47 are suspended by a balancer 49 supported by a suspension beam 48. The power supply line 50 is connected to the positive terminal of the welding power source 51, and the work 39 to be welded is connected to the negative terminal.

The welding torch is generally bent at its neck, but the suction nozzle is arranged in the bending direction of the torch according to the shape of the workpiece to be welded as shown in FIGS. , Bent in parallel or perpendicular directions. That is, the suction nozzle is substantially parallel to the welding line across the welding torch,
They are installed so as to be arranged on one straight line.

The suction nozzle 20 is connected via a suction duct 42 to a fume collection and removal device 52 whose required performance is determined according to the length of the duct. In this case, the tip nozzle of the suction nozzle 20 is brought as close as possible to the arc, that is, the fume generation source, so that the suction air volume of the recovery device 52 is small and a small and inexpensive one can be used. In addition, since the suction nozzle 20 itself is small and mounted integrally with the welding torch 2, there is no hindrance to loading and unloading the work to be welded to and from the welding position by the robot.

[0033]

As described above, according to the present invention,
A welding torch and a suction nozzle having a suction port for sucking welding fume are arranged along a welding line, and fume generated from a welded portion is suctioned and removed by the suction nozzle. The fume suction efficiency is extremely high because it can be installed at an optimum position in terms of suction efficiency independently of the welding torch in accordance with the flow of air. Further, since an insulating member having flexibility and electric insulation is detachably attached to the suction nozzle, the suction nozzle can be arranged as close as possible to the vicinity of the welded portion, Its suction efficiency is extremely high. In addition, since the insulating member of the suction nozzle is a flexible insulating material, the suction robot arranged close to the workpiece contacts the workpiece to be welded during operation teaching, and the welding robot stops operating. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

FIG. 4 is a view showing a specific example of an installation state of a welding torch and a suction nozzle shown in FIG. 2;

FIG. 5 is a diagram showing a modification of the same.

FIG. 6 is a diagram showing a welding robot to which a welding torch and a suction nozzle of the present embodiment are attached.

FIG. 7 is a view showing a conventional bead-on-plate welding method.

FIG. 8 is a view showing a conventional fillet welding method.

FIG. 9 is a view showing a conventional butt welding method.

FIG. 10 is a graph showing a discrete width of a fume gas flow in each welding method.

FIG. 11 is a schematic view showing a state in which fumes are collected by a welding torch with a fume suction port.

[Explanation of symbols]

 1, 8, 9: Material to be welded 2: Welding torch 3: Welding wire 4: Arc 5: Welding bead 6: Horizontal plate 7: Standing plate 10: Backing plate 11: Welding torch with fume suction port 12: Fume suction port 20: Suction nozzle 21, 22, 23: Insulating member 24: Tip member 54: Pressure regulator

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B23K 9/29 B23K 9/32 B01D 46/00

Claims (5)

(57) [Claims] 1. A welding torch and a suction nozzle having a suction port for sucking welding fume are arranged along a welding line to supply a shielding gas from the welding torch and to be supplied via the welding torch. A welding fume suctioning and removing method in which welding is performed by an arc generated between a welding wire and an object to be welded, and fume-containing air from a welded portion is suctioned by the suction nozzle. And an insulating member having electrical insulation properties are detachably attached, and the suction air volume of the suction nozzle is 0.2 m ³ /
Minutes or more, and the welding torch and the suction nozzle
A welding fume suction removal method characterized by being separated by 30 mm or more . 2. The suction fume removing method according to claim 1, wherein the insulating member is attached to a tip of the suction nozzle. 3. The method according to claim 1, wherein the insulating member is disposed at a position hidden by an outer edge of the welding torch when viewed from an arc point. 4. The welding fume suction according to claim 2, wherein the insulating member has a tip portion inclined with respect to an axis so as to be hidden by an outer edge portion of the welding torch as viewed from an arc point. Removal method. 5. The method according to claim 1, wherein the insulating member is provided in the middle of a suction nozzle.