JP5104611B2 - Automatic welding head for both internal and external surfaces of fixed pipes on site - Google Patents

Description

  The present invention relates to a welding head that automatically performs butt welding of pipe ends of pipes of various plants and the like.

  Conventionally, various automatic welding heads have been proposed for performing butt welding of pipes. This automatic welding head is composed of a traveling device capable of traveling along guide rails arranged along the outer peripheral portion or inner peripheral portion of the pipe, and a welding torch and other devices mounted on the traveling device, and is welded. In this case, the traveling device performs butt welding of the pipe end with a welding torch while traveling along the guide rail of the pipe.

A welding apparatus for performing circumferential butt welding of a pipe is disclosed in Patent Document 1.
This apparatus will be described with reference to FIG. Reference numeral 20 denotes a circumferential guide rail attached to the abutted pipe 10, and 21 denotes a welding head which automatically performs welding installed on the circumferential guide rail 20. The welding head 21 travels on the outer peripheral surface of the pipe 10 while being guided by the circumferential guide rail 20, a slide X-axis 23 provided on the traveling device 22 and slidable in the groove width direction, and a slide A slide Y-axis 24 connected to the X-axis 23 and slidable in the torch height direction, a torch support 25 attached to the slide Y-axis 24 so as to be swingable in the pipe circumferential direction, and rotatable to the torch support 25 And a wire feeding device 27 provided on the traveling device 22. A traveling device 22 of the welding head 21 is provided at a lower portion of the traveling carriage 221 and the traveling carriage 221, and is provided at a lower portion of the traveling carriage 221 and a traveling wheel 222 that meshes with the outer teeth 202 of the circumferential guide rail 20. A gripping mechanism 223 that grips both ends of the rail 20 and a Z-axis motor 224 with a Z-axis encoder 225 that is provided on the traveling carriage 221 and is driven are configured.
231 is an X-direction drive mechanism that drives the slide X-axis 23 in the groove width direction, 241 is a Y-direction drive mechanism that drives the slide Y-axis 24 in the torch height direction, and 251 is an angle of the welding torch 26 in the β direction. A β-direction drive mechanism to be adjusted, 261 is a rotary drive welding mechanism inside the welding torch, has an R-axis encoder 263, and has a rotary motor 262. The wire feeding device 27 includes a wire feeding motor 272 that drives a wire feeding mechanism 271 and a wire reel 274. A conduit cable 30 includes a welding wire 31 and a traveling position detector 29 provided on the traveling carriage 22.

The automatic welding head is required to have the following functions.
(1) Run smoothly on the guide rail. Needless to say that knocking or the like does not occur, it is desirable that local running failure due to backlash is also minimized.
(2) The welding head is firmly held by the rail without dropping over the entire posture.
(3) When traveling on the guide rail, the traveling part should not hit the guide rail or the base material part.
(4) Easy to attach to and detach from the guide rail.
(5) There should be little play in the left / right and up / down directions with respect to the welding direction during travel. (In practice, it should be within ± 0.1mm)
(6) There is little variation in traveling speed within a predetermined range (actually about ± 3.0%), and the variation in traveling speed in a certain welding position is reproducible.
(7) Driving even if the curvature changes within a certain range.
(8) Travel with the same error in the required welding speed range.
(9) Travel without significantly damaging the guide rail. On the other hand, the running section should not be significantly damaged by the guide rail.

Various apparatuses have been proposed as automatic welding heads.
In Patent Document 2, a guide device that serves as a guide for causing a welding torch to travel along a weld line of a welded pipe is fixed to a ring-shaped guide fitting main body that can be divided into a plurality of pieces and the circumference of the pipe. There is disclosed a guide device that is configured to be fixed to the circumference of a tube by being configured with a fixing tool for the purpose. However, this guide device is for welding the outer periphery of the pipe, and is not applicable to the welding of the inner peripheral surface.

  Patent Document 3 is an automatic welding machine including a traveling device that travels following the outer peripheral surface of a pipe, and a gas shield arc welder that is supported by the traveling device and performs butt welding of the pipe end of the pipe, An annular member is provided on the outer peripheral surface of the tube, which is a band-like and annular member having a certain width and is provided with two rails and a rack rail that are integrated with the annular member at both ends in the width direction. An automatic welding machine has been disclosed in which a traveling carriage having a pinion gear meshing with the rack rail of the annular member and having a welding torch fixed is caused to travel along the annular member. However, this guide device is also for welding the outer periphery of the tube, similar to that described in Patent Document 1, and is not applicable to the welding of the inner peripheral surface.

  Patent Document 4 discloses an automatic welding method in which a circumferential inner surface of a fixed steel pipe is butt welded, and a guide rail is provided in the circumferential direction of the inner peripheral surface of the steel pipe, and the self-propelled welding head is guided by the guide rail. A method is described in which the inner surface in the circumferential direction of the steel pipe is butt welded while running. However, this guide device is for welding the inner periphery of the pipe, and is not applicable to welding of the outer peripheral surface.

Patent Document 5 discloses a welding traveling device including a traveling carriage equipped with a device necessary for welding, such as a welding torch and a welding wire, and a guide rail that travels while guiding the traveling carriage. A device that can be easily attached to and detached from a rail is disclosed.
This mechanism itself can be applied to both the case where the guide rail is provided on the inner peripheral surface and the case where the guide rail is provided on the outer peripheral surface, but no description is given regarding the compatibility.

  As described above, when performing automatic circumferential welding of steel pipes, outer surface welding is equipped with a guide rail on the outer surface side, inner surface welding is equipped with a guide rail on the inner surface side, and a welding head is placed on the guide rail. A method of mounting and performing automatic welding is common. However, since the curvature of the guide rail on the outer surface side and the guide rail on the inner surface side is opposite, the welding heads are incompatible with each other.

Japanese Patent Laid-Open No. 4-200866 JP 54-54936 A JP-A-7-314132 JP 58-65579 A Japanese Utility Model Publication No. 3-12471

  An object of the present invention is to provide an automatic welding head for both inner and outer surfaces that can be used for both welding of the inner peripheral surface of a pipe and welding of the outer peripheral surface.

The present inventors separate the traveling device and other parts (torch part, torch left / right axis, torch vertical axis, wire feeding part, etc.) of the welding head, and only the traveling part is dedicated to the outer peripheral surface and inner peripheral surface. The present invention has been completed by finding that the above-mentioned problems can be achieved by using the other part also as the inner and outer peripheral surfaces.
That is, the present invention relates to a welding head as described below.

(1) A head of an automatic welding machine that runs on rails arranged along the circumferential direction of the outer peripheral surface and the inner peripheral surface of the on-site fixed pipe and performs one-side welding of the outer peripheral surface and the inner peripheral surface. The head includes a traveling device capable of traveling along the rail and a device group supported by the traveling device. The device group includes at least a welding torch, a vertical movement mechanism of the welding torch, and a horizontal movement of the welding torch. And a wire feeding mechanism, and the traveling device can travel on both the outer peripheral rail and the inner peripheral rail as it is or by exchanging all or part of the traveling device. device and said unit group is arranged closer all within the range satisfying both the physical extent permitted during physical range and an inner peripheral surface welding is permitted during peripheral surface welding simultaneously, the running device Arranged on top of rail A traveling vehicle and a support vehicle portion disposed below the rail, the travel vehicle and the support vehicle portion sandwiching the rail to grip the rail and support the welding head, An automatic welding head for both the inner and outer circumferences of a field-fixed pipe, wherein the vehicle portion is disposed so as to be replaceable according to the curvature of the outer circumference and the inner circumference of the pipe.
( 2 ) The traveling vehicles are provided in two pairs along the direction of the rail, and the supporting vehicle portions are disposed one pair directly below each of the two pairs of traveling vehicles ( 1 ). Automatic welding head for both internal and external surfaces of fixed pipes in the field.
(3) the vehicle is provided 2 pairs along the direction of the rail, support wheel unit is characterized in that it is a pair disposed immediately below the intermediate position of the vehicle of the two pairs (1), wherein Automatic welding head for both internal and external surfaces of fixed pipes in the field.
( 4 ) The inside of the on-site fixed pipe according to any one of (1) to ( 3 ), wherein a physical range allowed at the time of the outer circumferential surface welding is within a range of 200 mm or less on the upper surface of the steel pipe surface. Automatic welding head for external use.
( 5 ) The automatic welding head for both the inner and outer surfaces of the on-site fixed pipe according to any one of (1) to ( 4 ), wherein the pipe diameter during the outer circumferential surface welding is 150A to 1800A.
( 6 ) The automatic welding head for both internal and external surfaces of the on-site fixed pipe according to any one of (1) to ( 5 ), wherein a pipe diameter at the time of welding the inner peripheral surface is 800 A or more.

  According to the present invention, it is not necessary to separately have an inner peripheral surface welding device and an outer peripheral surface welding device, the operating rate of the device is improved, and the basic configuration of the device is the same, so that maintenance of the device is easy. Therefore, a small number of maintenance parts can be stored because two models are replaced with one model. Further, since the same operation is performed on the inner and outer peripheral surfaces, operator training is halved, operation errors are reduced, and as a result, quality can be improved. Furthermore, the upgrade of the model can be carried out simultaneously on the inside and outside, so the development investment for high performance can be halved.

  The welding head of the present invention travels on the outer circumference and the rail disposed along the inner circumference with respect to the outer peripheral surface of the small-diameter fixed pipe and the inner circumference of the medium-diameter fixed pipe, and performs single-side welding. It is a welding head of an automatic welding machine for both inner and outer circumferences that can be implemented in common.

The welding head of the present invention includes at least the following devices and mechanisms.
(1) Traveling device capable of traveling along rails (2) Welding torch (3) Welding torch vertical movement mechanism (4) Welding torch horizontal movement mechanism (5) Wire feed mechanism Also, welding head In addition to the above-mentioned devices and mechanisms, for example, a CCU (camera controller) integrated camera for remotely monitoring the welding state can be mounted as necessary.
The present inventors separated the traveling device and other parts (the welding torch, the welding torch vertical movement mechanism, the welding torch left and right movement mechanism, the wire feeding mechanism) of the welding head, and the outer surface of the traveling head alone. The configuration is exclusively for the inner surface, and the other portion is also configured for the inner and outer surfaces.

The traveling device is configured to be able to travel while directly supporting the entire head with respect to the curvature of the outer peripheral rail and the curvature of the inner peripheral rail as it is or by exchanging all or part of the components.
The traveling device only needs to be capable of traveling along the rail provided on the peripheral surface of the pipe. Specifically, the traveling device is disposed on the upper surface of the rail, and is disposed on the lower surface of the rail, and cooperates with the traveling vehicle. And a driving mechanism for the carriage. The carriage includes a support carriage unit that holds the welding head main body on the rail by sandwiching and holding the rail.
By adopting a configuration in which the rail travels on a rail and a carriage including a support vehicle portion, the welding head can be moved stably and smoothly. In addition, by adopting a configuration in which the rail is sandwiched and held between the traveling vehicle and the support vehicle portion, the welding head can be stably held on the rail, and can be easily attached to and detached from the guide rail.

The traveling vehicles are supported by the frame of the carriage, and two pairs are provided along the rail direction from the viewpoint of stably holding the welding head.
Moreover, a support vehicle part can be provided in two pairs along the direction of a pair or rail.
In order to securely sandwich and hold the rail, when a pair of supporting vehicle parts are provided, they are arranged directly below the intermediate position of the two pairs of traveling vehicles, and when two pairs of supporting vehicle parts are provided, each of the two pairs of traveling vehicles is provided. It is arranged directly under each pair. It is preferable to provide two pairs of support wheels because the posture of the welding head can be stabilized.

FIG. 1 illustrates an apparatus configuration in the case of welding the outer peripheral surface of a small-diameter fixed pipe.
The traveling device includes a carriage 4, a traveling vehicle 5 provided on the carriage 4, a support vehicle portion 6, a drive mechanism, and the like.
In order to enable the traveling device to travel according to the curvature of the outer periphery of the tube and the curvature of the inner periphery, all or part of the traveling device can be replaced. Specifically, the entire vehicle including the traveling vehicle, the supporting vehicle portion, its holding mechanism and the propulsion mechanism may be replaced, or may be partially replaceable.
The carriage 4 is exchanged for use on the inner surface and the outer surface.
The relationship between the distance between the traveling vehicles and the distance between the supporting vehicle portions is such that the distance between the traveling vehicles is larger than the distance between the supporting vehicles when welding the outer peripheral surface, and the distance between the traveling vehicles is smaller than the distance between the supporting vehicle portions when welding the inner peripheral surface To be.
Specifically, when the outer peripheral surface traveling device is changed to the inner peripheral surface, the portion that contacts the inner rails on both ends along the rail of the traveling device is shortened, and the distance between the supporting vehicle portions with respect to the traveling vehicle is shortened. Is arranged slightly wider than the interval between the traveling vehicles.
Depending on the type of piping, there is a case where the rail travel on the outer circumference and the inner circumference is possible without being replaced, and in this case, it may be used without being replaced.

The welding head includes a traveling device and a device group attached to the carriage 4 of the traveling device.
Specifically, the device group includes a torch peripheral unit 7 (torch, torch up / down unit, torch left / right unit, control relay box), CCD camera unit 9, travel motor, wire feeding unit 8, and the like. Commonly used in outer surface welding heads

  In order to allow the welding head to be used for both inner circumference welding and outer circumference welding, each member constituting the welding head (running device, welding torch, vertical movement mechanism of the welding torch, horizontal movement mechanism of the welding torch, wire) The feed mechanism and the like are all arranged within a range that simultaneously satisfies both the physical range allowed during outer peripheral surface welding and the physical range allowed during inner peripheral surface welding. By doing in this way, in any welding of inner circumference welding and outer circumference welding, a welding head does not come into contact with a rail or a pipe wall, and traveling is not hindered.

When performing on-site welding, there is an example in which the distance between adjacent pipes and obstacles approaches 200 mm. Accordingly, it is preferable that the height from the pipe surface of the welding head allowed at the time of outer circumferential surface welding is within 200 mm.
Moreover, it is preferable that the pipe diameter at the time of outer peripheral surface welding is 150A to 1800A, and it is preferable that the pipe diameter at the time of inner peripheral surface welding is 800A or more.
If the fixed pipe at the work site is a small diameter pipe, when the outer circumferential surface welding head is run on the guide rail, the belly of the welding head hits the guide rail, the balance between the traveling vehicle part and the supporting vehicle part is poor and stable. There is a problem of not being able to run. Therefore, it is preferable that the pipe diameter at the time of outer peripheral surface welding is 150 A or more. Similarly, when the on-site fixed pipe is a small-diameter pipe, the pipe type at the time of welding on the inner peripheral surface is preferably 800 A or more for reasons of running.

The present invention will be described below with reference to the drawings.
FIG. 1 shows a case where the outer peripheral surface of a small-diameter fixed pipe is welded as described above. A guide rail 2 is fixed to the outer periphery of the pipe 1, and the welding head 3 moves along the guide rail 2. While doing the welding work. The traveling device has a traveling carriage 4, a traveling vehicle 5 provided at a lower portion of the traveling carriage 4, and a support vehicle portion 6. The travel vehicle 5 and the support vehicle portion cooperate to sandwich the rail to hold the rail. And supporting the welding head.
The welding head has at least a traveling part, a torch peripheral unit (welding torch, welding torch vertical movement mechanism, welding torch horizontal movement mechanism) 7, and a wire feeding mechanism (wire feeding unit). The CCD camera unit 9 and the like are mounted accordingly.

When welding the outer periphery of a pipe as shown in Fig. 1, the shape and structure of the welding head does not particularly affect the welding operation, so there is a considerable degree of freedom in the shape, structure and spatial arrangement of the welding head. There is. However, if this welding head is directly applied to the welding of the inner peripheral portion, there arises a problem that the elements constituting the welding head hit the guide rail.
For example, FIG. 2 shows the case where the welding head used in FIG. 1 is used for welding the inner periphery of the pipe, and the welding head contacts the guide rail at the portions indicated by a, b and c in the figure. The trouble of doing occurs.
Moreover, since the curvature of outer periphery welding and the curvature of inner periphery welding are opposite, it is necessary to use the welding head provided with the traveling apparatus suitable for each.

Therefore, in the present invention, the traveling device and other portions of the welding head are separated, the traveling device is configured exclusively for outer surface welding and inner surface welding, and the other portions are also used for inner and outer surfaces.
A specific example is shown in FIG. In this example, the carriage 4 used for the outer circumference welding is replaced with a carriage 4 'suitable for inner circumference welding, and the elements constituting the welding head other than the traveling device are shapes and structures that can be used for the carriage 4 and the carriage 4'. Each of them is configured to be detachably attached to the carriage 4 and the carriage 4 ′.
In the carriage 4, each element can be installed in a direction along the traveling direction of the carriage, but in the carriage 4 ′, an arrangement is made such that the portions b and c shown in FIG. 2 do not contact the guide rail. Each element is arranged on the carriage so that Further, a shown in FIG. 2 can avoid contact with the guide rail by changing the cart 4 to the cart 4 ′.

  Since the automatic welding head of the present invention can be used for both the welding of the inner peripheral surface of the pipe and the welding of the outer peripheral surface, the operating rate of the apparatus is improved and the maintenance of the apparatus is facilitated. Can be suitably used as a welding head for butt circumference welding.

It is the figure which showed a mode that the outer peripheral surface of a small diameter fixed pipe was welded. It is a figure which shows a mode that the welding head used in FIG. 1 was used for the welding of the internal peripheral surface of a medium diameter fixed pipe. It is a figure which shows a mode that the inner peripheral surface of a medium diameter fixed pipe is welded using the welding head of this invention. It is a figure explaining the butt welding of the fixed pipe | tube of a prior art.

Explanation of symbols

(About FIGS. 1-3)
DESCRIPTION OF SYMBOLS 1 Pipe | tube 2 Guide rail 3 Welding head 4 Carriage 5 Traveling vehicle 6 Supporting vehicle part 7 Torch peripheral unit 8 Wire feed unit 9 CCD camera unit a, b, c The location where a welding head contacts with a guide rail
DESCRIPTION OF SYMBOLS 10 Pipe 20 Circumferential guide rail 21 Welding head 22 Traveling device 23 Slide X axis 24 Slide Y axis 25 Torch support body 26 Welding torch 27 Wire feeding device 30 Conduit cable 31 Welding wire 224 Z axis motor 231 X direction drive mechanism 232 X Axis motor 241 Y-direction drive mechanism 242 Y-axis motor 251 β-direction drive mechanism 252 β-axis motor 261 Rotation drive mechanism 262 Rotation motor 272 Wire feed motor

Claims (6)

A head of an automatic welding machine that travels on rails arranged along the circumferential direction of the outer peripheral surface and inner peripheral surface of the field fixing pipe and performs one-side welding of the outer peripheral surface and inner peripheral surface, The head includes a traveling device capable of traveling along the rail and a device group supported by the traveling device, and the device group includes at least a welding torch, a welding torch vertical movement mechanism, a welding torch left and right movement mechanism, and A wire feeding mechanism, and the traveling device can travel on both the outer peripheral rail and the inner peripheral rail as it is or by exchanging all or part of the traveling device. The device group is all disposed within a range that simultaneously satisfies both a physical range allowed during outer peripheral surface welding and a physical range allowed during inner peripheral surface welding , and the traveling device is disposed on the upper surface of the rail. Placed in A support vehicle portion disposed under the rail and the support vehicle portion, the support vehicle portion supporting the welding head by gripping the rail by sandwiching the rail. Is disposed so as to be exchangeable according to the curvature of the outer periphery and the inner periphery of the tube, and is an automatic welding head for both the inner and outer periphery of a field fixed tube. The traveling vehicle is provided 2 pairs along the direction of the rail, the site fixed things claim 1, wherein the support wheel unit are arranged in pairs directly below the respective vehicle of the two pairs Automatic welding head for both internal and external pipe surfaces. The traveling vehicle is provided 2 pairs along the direction of the rail, the site fixed things claim 1, wherein the support wheel unit is a pair disposed immediately below the intermediate position of the vehicle of the two pairs Automatic welding head for both internal and external pipe surfaces. The automatic welding head for both internal and external surfaces of a field-fixed pipe according to any one of claims 1 to 3 , wherein a physical range allowed at the time of welding the outer peripheral surface is within a range of 200 mm or less on the upper surface of the steel pipe surface. . Inner and outer surfaces combined automatic welding head situ fixed tube according to any one of claims 1 to 4, pipe diameter at the outer peripheral surface welding characterized in that it is a 150A～1800A. The automatic welding head for both the inner and outer surfaces of a field fixed pipe according to any one of claims 1 to 5 , wherein a pipe diameter at the time of the inner peripheral surface welding is 800A or more.

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