JP3709646B2 - ERW pipe welding equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric-welded pipe welding apparatus, and prevents sparks from being generated between a pair of flexible conductors.
[0002]
[Prior art]
In the case of manufacturing an electric resistance welded tube from a metal plate, after the metal plate is formed into a tubular shape, the gap portion of the V-shaped cross section is continuously heat-welded. As a means for heat welding, there are a contact type electric resistance welding apparatus using a high-frequency current and a non-contact type electric resistance welding apparatus that performs induction heating.
[0003]
First, a non-contact type electric resistance welder will be described. In FIG. 8, 1 is a high frequency power source, 2 is a transmission bus bar, 3 is a flexible conductor, 4 is a current transformer (CT), 5 is a coil, 6 is an electric resistance tube, and 7 is an aluminum shield duct. In order to center the ERW pipe 6 and the coil 5, the current transformer 4 can be moved ± 30 mm in the x and z directions, respectively, and y is the length direction of the ERW pipe 6 in order to determine welding conditions. It is possible to move 100 mm in the direction. Here, the distances y ₁ and y ₂ between the current transformer 4 and the shield duct 7 in the y direction are set to around 100 mm.
[0004]
In such an ERW pipe welding apparatus, the coil 5 welds the gap portion by induction heating the ERW pipe 6. On the other hand, since there is a gap between the current transformer 4 and the shield duct 7, dust easily enters the shield duct 7. For this reason, periodic disassembly and inspection of the shield duct 7 is necessary.
[0005]
Next, a contact type electric resistance welder will be described. FIG. 9 is a partial modification of FIG. 8, wherein 8 is a pair of contacts, 9 is a contact support means, 10 is a lifting platform, 11 is a screw shaft that is screwed with a nut member 12 attached to the lifting platform 10. A motor for rotating 13 forward and backward via a speed reducer 14, a hydraulic cylinder 15 attached to the elevator 10 and a tip of the rod 16 coupled to the current transformer 4, and a roller 17.
[0006]
In such an electric resistance welder, the current flowing in the electric resistance pipe 6 between the pair of contacts 8 flows through the V-shaped gap portion due to the proximity effect, and this portion is continuously welded. Since the pair of contacts 8 is located at the apex of the electric resistance welding tube 6, the elevator 10 is moved up and down within the range of z ₁ by the motor 11 according to the outer diameter of the electric resistance welding tube 6. Further, the contact 8 is urged to the electric sewing tube 6 through the contact support means 9 and is escaped when the electric welding tube 6 is uneven or the contact 8 is approaching the front and rear ends of the electric sewing tube 6. The hydraulic cylinder 15 operates and pulls up the contact 8 together with the current transformer 4 in the range of z ₂ to rapidly rise. That is, the pair of contacts 8 can move up and down in the range of z ₃ .
[0007]
[Problems to be solved by the invention]
However, when used as a contact-type electric resistance welder, the stroke of the contact 8 is remarkably larger than that of the non-contact type. Therefore, unless two or three types of flexible conductors 3 having different lengths are prepared, the flexible conductor 3 3 and the shield duct 7 approach each other to generate a spark and burn out. Further, by the position of the dimension y ₃ and z direction of the current transformer 4 in FIG. 9 (b), the falling to the y-direction is the length of the flexible conductor 3 is excessively large, flexible conductor each other or which the shield A spark is generated between the duct 7 and damaged.
[0008]
For these reasons, the work of removing the shield duct 7 and replacing the flexible conductor 3 has to be performed frequently, and it takes time to check the tightening of the mounting bolts and the leakage of cooling water.
[0009]
Therefore, an object of the present invention is to provide an electric resistance welded apparatus that solves such a problem.
[0010]
[Means for Solving the Problems]
In order to achieve such an object, the structure of the electric resistance welded pipe welding apparatus according to claim 1 is characterized in that a transmission head is coupled to the tip of a cylindrical transmission duct, and a current transformer is provided below the transmission head via a bellows cylinder. A pair of transmission bus bars, one end of which is connected to a high-frequency power source and disposed in the transmission duct, and the other end of each transmission bus bar and the current transformer are connected to a flexible conductor. Are connected individually via an insulation member, an insulating plate is provided on the inner surface of the transmission head via an insulating member, and a pair of flexible conductors are coupled to an insulating rod disposed substantially perpendicular to the flexible conductor in the transmission head. It is characterized in that an insulating plate is set so that both ends of the insulating rod slide, and an elevating means for raising and lowering the current transformer and an elevating means for rapidly raising the current transformer are provided.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
[0012]
The structure of the electric resistance welder according to the present invention is shown in FIGS. As shown in FIG. 2, a transfer means for moving the ERW pipe 6 in a direction perpendicular to the paper surface is provided, while an ERW pipe welding apparatus for welding the V-shaped gap portion of the ERW pipe 6 is provided. .
[0013]
A transmission duct 21 is provided on a movable table 20 that can move in directions perpendicular to each other on a horizontal plane, and a transmission head 22 is attached to the tip of the transmission duct 21. The transmission head 22 is formed of aluminum as a nonmagnetic material that shields high-frequency leakage magnetic flux. A housing 24 is attached under the transmission head 22 via a bellows tube 23. A current transformer 25 is accommodated in the housing 24. A pair of contacts 26 for energizing the electric sewing tube 6 and a support 27 for supporting the contacts 26 are attached to the current transformer 25 as heating means.
[0014]
A pair of transmission bus bars 28 having one end connected to a high frequency power source (not shown) are accommodated in the transmission duct 21. A fixed bus flange 30 is attached to the current transformer 25 via a power supply flange 29, and a fixed bus flange 31 is also attached to the other end of the pair of transmission bus bars 28, and a flexible conductor is provided between the fixed bus flanges 30 and 31. 32 is connected. As a result, high-frequency current and cooling water flow through the transmission bus bar 28.
[0015]
Next, the internal structure of the transmission head 22 will be described. As shown in FIG. 3, main openings are formed on the left and right sides of the transmission head 22, and a lid 33 that closes the main openings is attached via bolts 34. Further, as shown in FIG. 7, an auxiliary opening is formed on one side of the transmission head 22, and a lid 37 for closing the auxiliary opening is attached via a bolt. An insulating plate 35 is attached to the front and inner surfaces of the transmission head 22 and the inner side of the lid 33 through insulators 36 for the purpose of preventing high-frequency leakage magnetic flux and contact spark.
[0016]
In order to properly maintain the distance between the pair of flexible conductors 32 and the distance between the flexible conductor 32 and the insulating plate 35, the insulating rod 38 of FIG. 6 is provided. Four holes 39 are formed in the insulating rod 38, and a pair of flexible conductors 32 are connected via an insulating band 40 inserted through the holes 39 as shown in FIG. In this way, the two insulating rods 38 are attached to the pair of flexible conductors 32.
[0017]
As shown in FIGS. 3 and 4, the vicinity of the end portion on the power source side of the flexible conductor 32 is supported via an insulating support member 41. On the other hand, the conductor 42 that connects the non-power source side of the flexible conductor 32 and the current transformer 25 is supported by an insulating flange 44 that is attached to the upper portion of the housing 24 via an insulating member 43 as shown in FIG. .
[0018]
Next, the raising / lowering means 45 for raising / lowering the current transformer 25 with the contact 26 is demonstrated. As shown in FIG. 2, a rail 47 that is long in the vertical direction is formed on the frame body 46, and a lifting platform 48 is provided along the rail 47 so as to be movable up and down. The elevating table 48 is provided with a slide table 61 slidable in the vertical direction via a rail 60. The slide table 61 is coupled to the housing 24 via an insulating plate 49, while the nut material 51 is coupled to the arm 50 fixed to the lifting table 48, and the screw shaft 52 is screwed to the nut material 51. . The screw shaft 52 is linked to a motor 54 via a speed reducer 53. Here, the slide base 61 and the insulating plate 49 are coupled via an L-shaped steel 62. The L-shaped steel 62 and the slide base 61 are bolted through a long hole 62b extending in a direction perpendicular to the paper surface, while the L-shaped steel 62 and the insulating plate 49 are bolted through a long hole 62a extending in the left-right direction. Combined.
[0019]
In addition, a raising means 55 is provided for rapidly raising the contact 26 and the like. A hydraulic cylinder 56 is coupled to the frame 46, and its rod 57 faces the lower surface of the slide base 61. The hydraulic cylinder 56 is connected to a hydraulic pump 59.
[0020]
In FIG. 1, 59 is a pair of drum-shaped rollers that sandwich the electric sewing tube 6 from both sides, and 60 is a normal cylindrical roller.
[0021]
Next, the operation of the electric resistance welded pipe welding apparatus will be described. In order to raise and lower the contact 26 in accordance with the outer diameter of the electric sewing tube 6, the motor 54 is rotated. The rotational motion of the motor 54 is transmitted to the screw shaft 52 via the speed reducer 53, and the housing 24 is raised and lowered together with the nut material 51 screwed with the screw shaft 52. At this time, since the bellows tube 23 expands and contracts, the vertical movement of the housing 24 is not restricted. Further, since the flexible conductor 32 can be bent in the transmission head 22, the vertical movement of the current transformer 25 is not restricted. The distance between the flexible conductors 32 and the distance between the flexible conductors 32 and the left and right insulating plates 35 is always kept constant by the insulating rod 38 as shown in FIG. 3, while the flexible conductor 32 is shown in FIG. Does not approach the inner surface of the transmission head 22 due to the presence of the upper and front insulating plates 35.
[0022]
Next, in FIG. 1, when determining the distance y ₃ between the roller 60 and the contact 26 and providing a welding condition determination stroke, the long hole 62 b is released after loosening the bolt that joins the L-shaped steel 62 and the slide base 61. The L-shaped steel 62 is moved along the length direction of and the bolt is tightened. On the other hand, when moving the casing 24 in the x direction, after loosening the bolt that joins the L-shaped steel 62 and the insulating plate 49, the insulating plate 49 is moved along the length direction of the long hole 62a, and the bolt is Tighten. In either case, the bellows tube 23 absorbs the displacement of the relative position between the transmission head 22 and the housing 24.
[0023]
In order to perform welding of the electric sewing tube 6, the electric sewing tube 6 is energized through the pair of contacts 26 while the electric welding tube 6 is fed in the length direction by the rollers 59 and 60. If there is a convex portion or the like on the electric sewing tube 6 during welding, a sensor (not shown) detects this and operates the hydraulic pump 59, and the rod 57 of the hydraulic cylinder 56 rapidly pushes the contact 26 together with the slide base 61. .
[0024]
In FIG. 7, when the flexible conductor 32, the insulating rod 38, and the fixed bus flanges 30 and 31 are inspected, the lid 37 is opened. The flexible conductor 32 is attached or exchanged by opening the left and right lids 33 shown in FIG. At this time, since the left and right insulating plates 35 are also integrated with the lid 33, the pair of flexible conductors 32 connected by the insulating rod 38 can be removed integrally by removing the fixed bus flanges 30 and 31.
[0025]
In addition, it can replace with a contact as a heating means, and can also provide the coil for induction heating.
[0026]
【The invention's effect】
As can be seen from the above description, according to the electric resistance welding apparatus according to claim 1, the transmission bus bar and the flexible conductor connecting the high-frequency power source and the current transformer are sealed by the transmission duct, the transmission head, and the bellows tube. Therefore, the problem due to the adhesion of dust is solved without the flexible conductor or the like touching the outside air. Also, since the pair of flexible conductors are connected via an insulating rod and disposed between the insulating plates provided on the inner surface of the transmission head, the distance between the flexible conductors and the distance between the flexible conductors and the transmission head are arranged. Is kept at a constant value to prevent spark damage. Further, it is not necessary to prepare a plurality of flexible conductors having different lengths as in the prior art.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of an ERW pipe welding apparatus according to the present invention.
FIG. 2 is a right side view showing an embodiment of an ERW pipe welding apparatus according to the present invention.
FIG. 3 is an AA arrow view of FIG. 1 according to an embodiment of an electric resistance welder according to the present invention.
FIG. 4 is a view taken along the line CC in FIG. 3 according to an embodiment of the electric resistance welder according to the present invention.
FIG. 5 is a plan view of a housing according to an embodiment of an electric resistance welder according to the present invention.
FIG. 6 is a perspective view of an insulating rod according to an embodiment of an electric resistance welded pipe welding apparatus according to the present invention.
FIG. 7 is a view taken along the line B-B of FIG. 1 according to the embodiment of the electric resistance welder according to the present invention.
8A and 8B are related to a conventional non-contact type electric-welded pipe welding apparatus, in which FIG. 8A is a front view, and FIG. 8B is a right side view.
FIGS. 9A and 9B are related to a conventional contact type electric resistance welder, wherein FIG. 9A is a front view and FIG. 9B is a right side view;
[Explanation of symbols]
21 ... Transmission duct 22 ... Transmission head 23 ... Bellows cylinder 25 ... Current transformer 26 ... Contact 28 ... Transmission bus bar 32 ... Flexible conductor 35 ... Insulating plate 36 ... Insulator 38 ... Insulating rod 45 ... Lifting means 55 ... Lifting means

Claims (1)

A transmission head is coupled to the tip of a cylindrical transmission duct, a current transformer is coupled to the lower portion of the transmission head via a bellows cylinder, and a heating means is attached to the current transformer, while one end is connected to a high-frequency power source. The transmission bus bar is disposed in the transmission duct, the other end of each transmission bus bar and the current transformer are individually connected via a flexible conductor, and an insulating plate is provided on the inner surface of the transmission head via an insulating member. A pair of flexible conductors are coupled to an insulating rod arranged substantially at right angles to the flexible conductor in the transmission head, and both ends of the insulating rod are set to slide on opposite insulating plates, and the current transformer is moved up and down. An electric-welded pipe welding apparatus, comprising: lifting and lowering means for raising and a raising means for rapidly raising the current transformer.

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