JP2002137057A - Underwater welding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a locally dried underwater welding apparatus with a water evacuation nozzle positioning system that calculates a traveling distance of the water evacuation nozzle to gain a proper standoff distance and sets the standoff distance of the water evacuation nozzle at a proper value. SOLUTION: The apparatus has pre-stored data of proper offset and standoff values. The apparatus is provided with a non-consumable electrode and a voltage circuit made between the electrode and a work. A contact of the electrode with the work is detected by measuring voltage, current or resistance of the voltage circuit. A welding torch is dropped downward to a neighboring surface close to the welding portion of the work till the voltage circuit detects the contact of the non-consumable electrode with the work to measure the traveling distance of the torch. A proper standoff of the water evacuation nozzle is gained in such a manner that the predetermined distance between the bottom of the water evacuation nozzle and the front tip of the non-consumable electrode and the pre-stored proper standoff distance are deducted from the measured traveling distance of the welding torch shown above. The water evacuation nozzle is traveled downward by the balance of the calculation to set its standoff properly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding device for performing welding in water.

[0002]

2. Description of the Related Art As a means for performing local welding in water without draining water or the like in a tank storing water or the like, there is a local dry type underwater welding method. In this welding method, it is necessary to form a space that shields the water of the welded part,
As the method, there are a solid partition wall method in which a weld is shielded from surrounding water by a solid wall, and a fluid partition method in which a water shield space is formed in the weld by injecting water or gas at a high speed.

In these local dry underwater welding methods,
The standoff (almost 0 mm for a solid partition)
The quality of the water shield space has a significant effect. If the standoff is too short, there is a concern that movement of the non-consumable electrode is hindered by contact between the water exclusion nozzle and the base material due to unevenness of the surface of the base material serving as a welded portion. On the other hand, if the length is too long, the water shield space cannot be formed stably, and there is a fear that defects such as blow holes in the weld bead and burning of non-consumable electrodes may occur.In the worst case, the water shield space is formed. In some cases, welding cannot be performed. For this reason, the standoff must be set to an appropriate value determined in advance.

[0004] As a prior art relating to these local dry type underwater welding devices, for example, JP-A-9-1347 and JP-A-8-90222 are listed. In this prior art, neither the fluid partition method nor the solid partition method discloses a method for setting the position of the water removal nozzle.

[0005] Therefore, when operating the local dry welding apparatus remotely, the position of the water exclusion nozzle can be confirmed by the CC.
It is considered necessary to provide a method of setting the position of the water exclusion nozzle by arranging a D camera or the like.

[0006]

When local dry type underwater welding is performed by remote control, the error in the manufacturing dimensions with respect to the design dimensions increases as the target structure increases, and the shape of the welding target portion is grasped in advance and the It is difficult to set the position of the exclusion nozzle, and since the working environment is underwater, it is practically difficult for a human to approach the welding target and set the position of the water exclusion nozzle.

From the above, some means must be taken to set the standoff to an appropriate value. Therefore, a method is conceivable in which a sensor, a camera, or the like is separately installed near the water exclusion nozzle to adjust the position of the water exclusion nozzle.

However, installing a sensor, a camera, or the like around the water exclusion nozzle leads to an increase in the size of the device, which hinders use in a narrow portion. Also,
In the local dry type underwater welding method using a fluid partition, the fluid is jetted around the water exclusion nozzle at high speed and violent air bubbles are generated, so it is difficult to sense the sensor with a sensor and monitor the standoff with a camera. Setting may not be possible. Furthermore, when a sensor is used, there is a restriction that the height of the surface of the base material to be sensed and the surface of the base material forming the water shield space must be equal.

[0009] On the other hand, the number of cables connecting the working device and the control device as a remotely operated working device is reduced in weight,
From the viewpoint of maneuverability, the smaller the better, the better.

An object of the present invention is to provide a water exclusion nozzle position setting device capable of automatically setting a stand-off of a water exclusion nozzle without providing a separate device such as a sensor or a camera in the welding device, and an underwater welding device equipped with the same. Is to do.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a water elimination nozzle for forming a space in which water is locally excluded, a welding torch for performing welding by an electrode in the space, and applying the welding torch to a material to be welded. First moving means for moving up and down with respect to
In an underwater welding apparatus provided with a second moving means for moving the water removal nozzle up and down with respect to the workpiece, a voltage application circuit is provided between the electrode and the workpiece. A contact between the electrode and the workpiece is detected by an electrical change such as a voltage, current, or resistance of a circuit, and a moving distance until the electrode contacts the workpiece, and a first moving means. The distance between the tip of the electrode and the lower end face of the water elimination nozzle when the second moving means is at the origin and the predetermined distance from the lower end face of the water elimination nozzle to the workpiece, respectively, when the water elimination nozzle is used. This is achieved by calculating the amount of movement of.

Further, the present invention is achieved by providing means for storing a distance from the lower end surface of the water elimination nozzle to the surface of the workpiece.

[0013] It is also achieved by providing means for setting the position of the water removal nozzle.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a control flowchart of the water elimination nozzle position setting device when the voltage of a voltage application circuit formed between a non-consumable electrode and a base material is used as a control factor.

In FIG. 1, when the welding torch mounting stage and the water elimination nozzle mounting stage are both at the origin, the offset amount D of the two, the appropriate standoff value S for forming a good water shield space, and the standoff value S are shown. Water displacement nozzle mounting stage movement amount calculation formula Hn = H for calculating the water displacement nozzle mounting stage movement amount Hn required to perform
Store tDS. Next, the welding torch mounting stage and the water exclusion nozzle mounting stage are returned to their origins, and a voltage is applied to a pre-formed voltage application circuit between the non-consumable electrode and the base material. Thereafter, the welding torch mounting stage is driven in the direction of the base material, and the drive amount Ht from the origin and the voltage E of the voltage application circuit formed between the non-consumable electrode and the base material are monitored.

When the voltage E becomes almost 0 V, the driving of the welding torch mounting stage and the application of the voltage to the voltage application circuit are stopped, and the driving amount Ht from the origin at this time is stored. The welding torch mounting stage is returned to the origin, and the driving amount Ht from the origin is substituted into the water exclusion nozzle mounting stage movement amount calculation formula Hn = Ht-DS to calculate the water exclusion nozzle mounting stage movement amount Hn. Then, the stage for mounting the water exclusion nozzle is driven by the movement amount Hn, and the water exclusion nozzle is set at a position where the stand-off has an appropriate value.

FIG. 2 is a control flowchart of the water elimination nozzle position setting device when the current flowing through the voltage application circuit formed between the non-consumable electrode and the base material is used as a control factor.

In FIG. 2, the offset amount D when the welding torch mounting stage and the water elimination nozzle mounting stage are both at the origin, the appropriate standoff value S for forming a water shield space well, and the standoff value S. Water displacement nozzle mounting stage movement amount calculation formula Hn = H for calculating the water displacement nozzle mounting stage movement amount Hn required to perform
Store tDS.

Next, the welding torch mounting stage and the water exclusion nozzle mounting stage are returned to their origins, and a voltage is applied to a pre-formed voltage application circuit between the non-consumable electrode and the base material. Thereafter, the welding torch mounting stage is driven in the direction of the base material, and the drive amount Ht from the origin and the current I flowing through the voltage application circuit formed between the non-consumable electrode and the base material are monitored. Current I
When the value is no longer 0 A, the driving of the welding torch mounting stage and the application of the voltage to the voltage application circuit are stopped, and the driving amount Ht from the origin at this time is stored. The welding torch mounting stage is returned to the origin, and the driving amount Ht from the origin is calculated by a water displacement nozzle mounting stage moving amount calculation formula Hn.
= Ht-DS, calculate the water displacement nozzle mounting stage movement amount Hn, drive the water removal nozzle mounting stage by the movement amount Hn, and set the water removal nozzle at a position where the standoff is an appropriate value. .

FIG. 3 is a diagram schematically illustrating a procedure for setting the position of the water exclusion nozzle when the water exclusion nozzle position setting device of the present invention is mounted on a local dry type underwater welding apparatus having a fluid partition water exclusion nozzle.

In FIG. 3A, reference numeral 1 denotes a welding torch. The welding torch 1 has a holder 6 for a non-consumable electrode 4.
The welding wire guide 7 of the welding wire 17 and the welding part monitoring camera 8 are fixed. Although not shown, an injection port for injecting argon gas is provided in the welding torch 1. Further, the welding torch 1 moves up and down. Reference numeral 2 denotes a fluid partition water exclusion nozzle from which an argon gas is injected. The fluid partition wall eliminating nozzle 2 is provided with a welding torch 1
Move up and down as well. Reference numeral 5 denotes a large-sized odd-kind container storing water and the like (not shown), which is a base material of a welded portion.

When the welding torch 1 is at the origin Gt, the offset amount D when the fluid partition wall eliminating nozzle 2 is at the origin Gn, and as shown in FIG. Is stored in advance.

In FIG. 3B, the driving amount Ht from the origin when the welding torch 1 is brought into contact with the base material 5 is detected and stored.

In FIG. 3C, the welding torch 1 is returned to the origin Gt. In FIG. 3D, the water displacement nozzle driving amount Hn is calculated by using the driving amount Ht from the origin of the welding torch 1 stored in FIG. 3B as a factor, and the welding torch 1 and the water removing nozzle 2 are connected. By driving by the driving amount Hn, the water removal nozzle 2 is set to the stand-off S where a water shield space can be favorably formed.

FIG. 4 is a diagram schematically illustrating a procedure for setting the position of the water exclusion nozzle when the water exclusion nozzle position setting device of the present invention is mounted on a local dry type underwater welding apparatus having a solid partition wall water exclusion nozzle.

In FIG. 4A, a seal member 3a is attached to the tip of the solid partition wall water elimination nozzle 3.
When the solid partition wall water elimination nozzle 3 moves downward, the sealing member 3a comes into close contact with the base material 5 and is sealed. This allows
Water does not enter the welding torch 1 and the solid partition wall water elimination nozzle 3. The offset amount D when the tip of the welding torch is at the origin Gt and the tip of the solid partition wall water elimination nozzle 3 is at Gn, and the appropriate value S of the standoff that can form a good water shield space (in the case of the solid partition wall water elimination nozzle) Is approximately 0 mm).

In FIG. 4B, the driving amount Ht from the origin when the tip of the welding torch 1 contacts the base material 5 is detected and stored. In FIG. 4C, the welding torch 1 is returned to the origin Gt. In FIG. 4 (4), FIG.
Using the driving amount Ht from the origin of the welding torch 1 stored at the time of (2) as a factor, the water removing nozzle driving amount Hn is calculated, and the welding torch 1 and the solid partition wall water removing nozzle 3 are driven by the driving amount H.
By driving by n, the solid partition wall water elimination nozzle 3 is set to a stand-off S where a water shield space can be favorably formed.

FIG. 5 shows a water drain nozzle position setting device according to an embodiment of the present invention which detects contact between a non-consumable electrode and a base material by a voltage change of a voltage application circuit formed between the non-consumable electrode and the base material. It is a block diagram at the time of mounting in a dry type underwater welding apparatus.

In FIG. 5, a local dry type underwater welding apparatus for welding a base material 5 in water is a means for mounting a non-consumable electrode 4 and a means for forming a water shield space in a welded portion. And a water removal nozzle 2. 9 is
This is a welding torch moving stage that moves the welding torch 1 in a direction perpendicular to the base material 5. Reference numeral 10 denotes a welding torch moving stage control device that controls the welding torch moving stage 9. Reference numeral 11 denotes a water exclusion nozzle moving stage for moving the water exclusion nozzle in a direction perpendicular to the base material. Reference numeral 12 denotes a water exclusion nozzle movement stage control device that controls the water exclusion nozzle movement stage 11.

Numeral 14 denotes a rail, which is a traveling carriage on which the welding torch moving stage 9 and the water removing nozzle moving stage 11 are mounted, orbits on the rail 13 and travels in the welding advancing direction. Reference numeral 15 denotes a traveling vehicle control device that controls the traveling vehicle 14. Reference numeral 16 denotes a welding power source that generates an arc between the non-consumable electrode 4 and the base material 5. 1
8 is a wire supply device for sequentially supplying the welding wire 17. Reference numeral 19 denotes a power supply for applying a voltage to a voltage application circuit formed for detecting contact between the non-consumable electrode 4 and the base material 5. Reference numeral 20 denotes a switch for connecting a voltage application circuit between the non-consumable electrode 4 and the base material 5. 21 detects the contact between the non-consumable electrode 4 and the base material 5 by measuring and monitoring the voltage E between the non-consumable electrode 4 and the base material 5 by a voltage application circuit between the non-consumable electrode 4 and the base material 5. This is a non-consumable electrode contact detection device. 2
Reference numeral 2 denotes a control device that performs overall control of the above devices.

The means for moving in the direction of the welding line is not limited to the traveling carriage 14, but may be a robot, a manipulator, or the like.

The operation of the apparatus having the above configuration will be described below. First, the control device 22 moves the carriage 14 to the welding start position of the base material 5 to be welded, and returns the welding torch moving stage 9 and the water elimination nozzle moving stage 11 to the previously set and stored origins Gt and Gn. Next, the control device 22 activates the power supply 19, connects the switch 20, transmits a command to drive the welding torch moving stage 11 in the base material direction to the welding torch moving stage control device 10, and controls the welding torch moving stage 11. Start driving. At this time, the non-consumable electrode contact detection device 21 measures and monitors the voltage E, and when E ≒ 0, determines that the non-consumable electrode 4 and the base material 5 have contacted, and transmits it to the control device 22. In response, the control device 22 transmits a stop command to the welding torch moving stage control device 10 to stop driving the welding torch moving stage 9. At this time, the welding torch moving stage control device 10 transmits the drive amount Ht from the origin to the control device 22. Control device 22
Resets the welding torch moving stage 9 to the origin, substitutes the driving amount Ht from the origin into a previously set and stored water displacement nozzle displacement calculation formula, and calculates the water displacement nozzle displacement Hn. After that, the control device 22 transmits a command to drive the water exclusion nozzle movement stage 11 to the water exclusion nozzle movement stage control device 12 to drive the water exclusion nozzle movement stage 11,
Set the water exclusion nozzle 2 to an appropriate standoff. After setting the position of the water exclusion nozzle, the control device 22 forms a water shield space and starts local dry-type underwater welding.

As described above, in the present invention, the water exclusion nozzle may be any of a fluid partition method and a solid partition method. In addition, not only the setting at the welding start point, but also the teaching-playback construction generally performed in the automatic welding, at each teaching point, the water elimination nozzle position setting device of the present invention is used to set the water. The position of the exclusion nozzle may be set and taught. The power supply 19, the switch 20, and the non-consumable electrode contact detection device 21 forming the voltage application circuit may be provided in the welding power supply 16, and the cable of the voltage application circuit may also serve as the power supply cable which is an arc generation path. good.

FIG. 6 shows a water drain nozzle position setting device according to an embodiment of the present invention which detects contact between a non-consumable electrode and a base material by a change in current of a voltage application circuit formed between the non-consumable electrode and the base material. It is a block diagram at the time of mounting in a dry type underwater welding apparatus.

In FIG. 6, reference numeral 1 denotes a welding torch on which a non-consumable electrode 4 is mounted. Reference numeral 2 denotes a water elimination nozzle that forms a water shield space at the welded portion. Reference numeral 9 denotes a welding torch moving stage for moving the welding torch in a direction perpendicular to the base material. Reference numeral 10 denotes a welding torch moving stage control device that controls the welding torch moving stage 9. Reference numeral 11 denotes a water exclusion nozzle moving stage for moving the water exclusion nozzle in a direction perpendicular to the base material. Reference numeral 12 denotes a water exclusion nozzle movement stage control device that controls the water exclusion nozzle movement stage 11.

Numeral 14 denotes a traveling carriage on which the welding torch moving stage 9 and the water removing nozzle moving stage 11 are mounted, and which travels in the welding traveling direction on the rail 13 as a track. Reference numeral 15 denotes a traveling vehicle control device that controls the traveling vehicle 14. Reference numeral 16 denotes a welding power source which is a means for generating an arc between the non-consumable electrode 4 and the base material 5. Reference numeral 18 denotes a wire supply device that sequentially supplies the welding wire 17. 19 is a non-consumable electrode 4 and a base material 5
Is a power supply which is a means for applying a voltage to a voltage application circuit formed to detect contact with the power supply. 20 is a non-consumable electrode 4
And a switch as a means for connecting a voltage application circuit between the power supply and the base material 5. Reference numeral 24 denotes a non-consumable electrode contact detection device which is a means for detecting a contact between the non-consumable electrode 4 and the base material 5 by measuring and monitoring a current I flowing through a voltage application circuit between the non-consumable electrode 4 and the base material 5. It is. Reference numeral 22 denotes a control device which is a means for controlling the above devices in a centralized manner. Means for moving in the direction of the welding line is not limited to the traveling vehicle 14, but may be a robot, a manipulator, or the like.

The operation of the apparatus having the above configuration will be described below. First, the control device 22 moves the carriage 14 to the welding start position of the base material 5 to be welded, and returns the welding torch moving stage 9 and the water elimination nozzle moving stage 11 to the previously set and stored origins Gt and Gn. Next, the control device 22 activates the power supply 19, connects the switch 20, transmits a command to drive the welding torch moving stage 11 in the base material direction to the welding torch moving stage control device 10, and controls the welding torch moving stage 11. Start driving.

At this time, the non-consumable electrode contact detecting device 24 measures and monitors the current I, and when I ≠ 0, judges that the non-consumable electrode 4 and the base material 5 have come into contact with each other and transmits it to the control device 22. I do. In response, the control device 22 transmits a stop command to the welding torch moving stage control device 10 to stop driving the welding torch moving stage 9. At this time, the welding torch moving stage control device 10 transmits the drive amount Ht from the origin to the control device 22. The controller 22 returns the welding torch movement stage 9 to the origin, and substitutes the drive amount Ht from the origin into the water displacement nozzle displacement calculation formula which is set and stored in advance to calculate the water displacement nozzle displacement Hn.

Thereafter, the control device 22 transmits a command to drive the water exclusion nozzle movement stage to the water exclusion nozzle movement stage control device 12, drives the water exclusion nozzle movement stage 11, and sets the water exclusion nozzle 2 to an appropriate standoff. . After setting the position of the water exclusion nozzle, the control device 22 forms a water shield space and starts local dry-type underwater welding.

As described above, in the present invention, the water exclusion nozzle may be any of a fluid partition method and a solid partition method. In addition, not only at the setting at the welding start point, but in the teaching-playback type construction generally performed in automatic welding, at each teaching point, the water removal nozzle position setting device of the present invention provides: The position of the water removal nozzle may be set and taught. The power supply 19, the switch 20, and the non-consumable electrode contact detection device 24 forming the voltage application circuit may be provided in the welding power supply 16, and the cable of the voltage application circuit may also serve as the power supply cable which is an arc generation path. good.

That is, according to the present invention, there is provided a water removing nozzle for forming a space in which water is locally removed, a welding torch for performing welding by an electrode in the space, and moving the welding torch up and down with respect to a workpiece. An underwater welding apparatus provided with a first moving means for moving the water removing nozzle up and down with respect to the material to be welded, and a voltage between the electrode and the material to be welded. An application circuit is provided, and a contact between the electrode and the workpiece is detected by an electrical change such as a voltage, a current, or a resistance of the voltage application circuit, and a moving distance until the electrode contacts the workpiece. A distance from the tip of the electrode to a lower end surface of the water exclusion nozzle when the first moving unit and the second moving unit are each at the origin; and a predetermined distance from the lower end surface of the water exclusion nozzle to the workpiece. The distance from the drainage It is obtained to calculate the amount of movement of the nozzle.

Further, there is provided means for storing a distance from the lower end surface of the water removal nozzle to the surface of the workpiece.

Further, there is provided means for setting the position of the water removal nozzle. As described above, the present invention provides a local dry underwater welding device by grasping the distance between a non-consumable electrode and a base material from the voltage, current, resistance, or the like of a voltage application circuit formed between the non-consumable electrode and the base material. Can be automatically set to an appropriate standoff, so that an inexpensive water exclusion nozzle position setting device with a simple configuration that does not use a sensor or a camera can be provided.

[0045]

According to the present invention, a water exclusion nozzle position setting device capable of automatically setting a stand-off of a water exclusion nozzle without providing a welding device with a separate device such as a sensor or a camera, and an underwater welding device equipped with the same. Can be provided.

[Brief description of the drawings]

FIG. 1 is a control flowchart of a water removal nozzle position setting device of the present invention.

FIG. 2 is a control flowchart of the water removal nozzle position setting device of the present invention.

FIG. 3 is a diagram schematically illustrating a procedure of setting a water exclusion nozzle position when the water exclusion nozzle position setting device of the present invention is mounted on a local dry type underwater welding apparatus having a fluid partition water exclusion nozzle.

FIG. 4 is a diagram schematically illustrating a procedure for setting a water exclusion nozzle position when the water exclusion nozzle position setting device of the present invention is mounted on a local dry underwater welding apparatus having a solid partition wall water exclusion nozzle.

FIG. 5 is a block diagram in a case where the water removal nozzle position adjusting device according to the embodiment of the present invention is mounted on a non-consumable electrode welding device.

FIG. 6 is a block diagram in a case where the water removal nozzle position adjusting device according to the embodiment of the present invention is mounted on a non-consumable electrode welding device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Welding torch, 2 ... Water exclusion nozzle, 3 ... Water exclusion nozzle, 3a ... Seal member, 4 ... Non-consumable electrode, 5 ... Base material, 6
... Electrode holder, 7 ... Welding wire guide, 8 ... Welding part monitoring camera, 9 ... Welding torch moving stage, 10 ... Welding torch moving stage controller, 11 ... Water removing nozzle moving stage, 12 ... Water removing nozzle moving stage controller , 13
... Rail, 14 ... Traveling trolley, 15 ... Traveling trolley control device, 16 ... Welding power supply, 17 ... Welding wire, 18 ... Welding wire feeding device, 19 ... Power supply, 20 ... Switch, 21 ... Non-consumable electrode contact detection device, 22: control device, 23: water, 2
4: Non-consumable electrode contact detection device, D: Offset amount at initial (at home return), S: Appropriate value of stand-off, Hn
... The distance of movement of the water elimination nozzle from the origin for setting the standoff to an appropriate value, Ht the distance from the tip of the non-consumable electrode to the base material when returning to the home position, E the voltage of the voltage application circuit between the non-consumable electrode and the base material , I: current flowing through a voltage application circuit between the non-consumable electrode and the base material, Gt: origin of the welding torch, Gn: origin of the water removal nozzle.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ken Obana 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term in Hitachi Research Laboratory, Hitachi, Ltd. (Reference) 4E001 AA03 BB07 DF08 4E082 AA07 AA11 EB01 EC01 EC11

Claims (3)

[Claims] 1. A water removal nozzle for forming a space in which water is locally removed, a welding torch for performing welding by an electrode in the space, and a first moving up and down movement of the welding torch with respect to a workpiece. In an underwater welding apparatus provided with a moving unit and a second moving unit that moves the water removal nozzle up and down with respect to the workpiece, a voltage application circuit is provided between the electrode and the workpiece. ,
The contact between the electrode and the material to be welded is detected by an electrical change such as voltage, current, or resistance of the voltage application circuit, and the distance traveled until the electrode contacts the material to be welded, The distance from the tip of the electrode to the lower end face of the water elimination nozzle when the moving means and the second moving means are respectively at the origin, and the predetermined distance from the lower end face of the water elimination nozzle to the material to be welded, An underwater welding apparatus for calculating a movement amount of a water removal nozzle. 2. The underwater welding apparatus according to claim 1, further comprising means for storing a distance from a lower end surface of the water elimination nozzle to a surface of the workpiece. 3. The underwater welding apparatus according to claim 1, further comprising means for setting a position of the water removal nozzle.