JP5633311B2 - Metal circular pipe manufacturing apparatus and manufacturing method - Google Patents

Description

  The present invention relates to a manufacturing apparatus and a manufacturing method of a metal circular pipe for welding in a state in which a butting portion of a cylindrical workpiece is butted, and in particular, the butting portion can be butted so that an outer peripheral surface thereof is flat. The present invention relates to a metal circular pipe manufacturing apparatus and a manufacturing method.

  As a method of manufacturing a metal circular tube from a metal plate, there is a method in which a metal plate is roll-formed into a cylindrical shape by various roll groups and welded in a state in which a butt portion which is a circumferential end portion is abutted. In this method, it is important to abut the abutting portion so that the outer peripheral surface thereof is flat. This is because, for example, when the butt portion is butted in a state where a step is generated, the surface of the butt portion melted by welding does not become flat. Thereby, the volume of the part joined by the melted butt | matching part reduces, and the joining strength of a metal circular pipe will fall. In addition, the outer peripheral surface of the metal tube is not flat, looks bad, and the quality of the metal tube deteriorates. Thus, as a method for abutting the butted portion so that the outer peripheral surface thereof is flat, for example, there is a method described in Patent Document 1 below.

  In the method described in Patent Document 1 below, as shown in FIG. 11, rollers 141 and 142 are arranged on the left and right with respect to the cylindrical workpiece 110, and the rollers 110 and 142 are arranged in the conveying direction of the workpiece 110. Rollers 143 and 144 are arranged on the outlet side. A roller 145 is disposed on the inner peripheral surface side of the abutting portion 110a and a roller 146 is disposed on the outer peripheral surface side of the abutting portion 110a on the inlet side in the conveyance direction of the workpiece 110 from the welding position of the welding tool 122. . In this way, the workpiece 110 is pressed from the left and right of the workpiece 110 and from the inner and outer peripheral surfaces of the butting portion 110a, and the butting portion 110a is adjusted so that the outer circumferential surface is flat.

JP 2002-248519 A

  By the way, in the above-described method, the pressing force and the pressing position that the left and right rollers 141, 142, 143, and 144 press against the work 110 must be made equal to each other, and it is difficult to adjust the pressing force and the pressing position. It was. In particular, when there is a manufacturing error (accuracy variation) in the workpiece 110 itself, that is, as shown in FIG. 12A, when the outer peripheral length is a workpiece 110A that differs depending on the axial direction (d1 ≠ d2), Alternatively, as shown in FIG. 12B, when the end surface of the abutting portion 110a is a workpiece 110B that undulates along the axial direction, the outer peripheral surface is flattened according to the position of the abutting portion 110a. It has been difficult to abut the abutting portion 110a at an appropriate position by changing the pressing force and the pressing position for matching.

In the above-described method, the abutting portion 110a is pressed from above and below by the upper and lower rollers 145 and 146. As a result, even if there is a step in the butt portion 110a as shown in FIG. 12C, this step can be eliminated. However, in this case, the frictional force acting on the outer peripheral surface of the abutting portion 110a is increased, and the outer peripheral surface is scratched and the quality may be deteriorated.
Furthermore, since the pressing means 140 (each roller 141, 142, 143, 144, 145, 146) shown in FIG. 11 presses in the up and down direction and the left and right direction, there are many pressing directions, and driving for driving each roller. The pressing operation of the mechanism was complicated. Moreover, since each roller is arrange | positioned with respect to the workpiece | work 110 at right and left, and upwards, there also existed a problem that the press means 140 containing each roller and a drive mechanism enlarged.

  The present invention has been made in order to solve the above-described problems, and the abutting portion can be abutted so that the outer peripheral surface thereof is flat without complicating the pressing work and increasing the size of the pressing means. An object of the present invention is to provide a manufacturing apparatus and a manufacturing method for a metal circular pipe.

The metal circular pipe manufacturing apparatus according to the present invention welds using a welding tool in a state in which a butting portion which is a circumferential end portion of a workpiece which is roll-formed into a cylindrical shape and is conveyed is butted. A cylindrical mold having a through hole having a slightly larger hole diameter than the outer diameter of the work, and the butting portion in the circumferential direction of the work in a state where the work is inserted through the through hole of the cylindrical mold. the opposite site located on the opposite side and a pressing means for pressing the shaft center of the workpiece, said pressing means has a plurality of pressing device, Ru are arranged at different positions in the conveying direction of the workpiece There is a special feature.

Further, in the metal tube manufacturing apparatus according to the present invention, the pressing means presses the opposite portion on the inlet side of the workpiece conveying direction from the welding position of the welding tool, and makes the butting portion abut. It is preferable to have one pressing device.
Further, in the metal circular pipe manufacturing apparatus according to the present invention, the pressing means presses and melts the opposite portion at the welding position of the welding tool or the outlet side in the conveyance direction of the workpiece from the welding position. It is preferable to have a second pressing device that shapes the butt portion.
In this case, a butt shape measuring means for measuring the shape of the gap of the butt portion on the inlet side in the workpiece conveyance direction from the welding position, and an outlet side in the workpiece conveyance direction from the welding position or the welding position. Then, based on the measured values of the bead shape measuring means for measuring the shape of the melted bead of the butt portion, and the butt shape measuring means and the bead shape measuring means, the second pressing device presses the opposite portion. It is preferable to include an electronic control device that determines a pressing position and controls driving of the second pressing device.

Further, in the metal circular pipe manufacturing apparatus according to the present invention, the pressing means has the butt portion melted by pressing the opposite portion on the outlet side in the workpiece conveying direction from the second pressing device. It is preferable to have a third pressing device that maintains the state.
The metal circular pipe manufacturing apparatus according to the present invention further includes guide means for aligning the abutting portion in the circumferential direction, and the guide means has a predetermined gradient with respect to the workpiece conveying direction. It is preferable to have a blade portion that extends and enters the gap of the abutting portion on the inlet side in the conveyance direction of the workpiece and exits from the gap of the abutting portion on the outlet side in the conveyance direction of the workpiece.

The method of manufacturing a metal circular pipe according to the present invention uses a welding tool in a state in which a workpiece roll-formed in a cylindrical shape is conveyed in the axial direction and a butting portion which is a circumferential end portion of the workpiece is butted. A conveying step in which a workpiece having an outer diameter slightly smaller than the diameter of the through hole is inserted into the through hole and conveyed with respect to the cylindrical mold having the through hole, and the workpiece A pressing step of pressing an opposite portion located on the opposite side of the abutting portion in the circumferential direction of the workpiece toward the axial center of the workpiece by pressing means including a plurality of pressing devices arranged at different positions in the conveying direction of the workpiece; , Is characterized by comprising.

Further, in the method of manufacturing a metal circular pipe according to the present invention, in the pressing step, the opposite portion is pressed against the welding position of the welding tool from the welding position of the welding tool to butt the butt portion. Is preferred.
Further, in the method of manufacturing a metal circular pipe according to the present invention, in the pressing step, the welding position of the welding tool or the outlet side in the conveyance direction of the workpiece from the welding position is pressed and melted at the opposite portion. It is preferable to shape the butt portion.
Moreover, in the manufacturing method of the metal circular tube which concerns on this invention, you may convey the workpiece | work whose axial direction length is 500 mm or less in the said conveyance process.

Therefore, according to the manufacturing apparatus and the manufacturing method of the metal circular pipe according to the present invention, the workpiece is pressed in a floating state with respect to the through hole of the cylindrical mold, and the outer peripheral surface of the workpiece is penetrated by the cylindrical mold. Deform along the hole. As described above, since it is assumed that the outer peripheral surface of the workpiece is deformed, even if there is a manufacturing error (accuracy variation) in the workpiece itself, the outer peripheral surface of the butt portion is flexibly deformed, and the butt portion is moved to the outer periphery. It can be abutted so that the surface is flat.
Further, according to the present invention, the pressing means presses the opposite portion located on the opposite side of the butting portion in the circumferential direction of the workpiece toward the axial center of the workpiece. For this reason, a press means presses a workpiece | work from one direction, and does not press from multiple directions. Therefore, complication of the pressing work can be prevented. Further, since the pressing means is not arranged at a position in multiple directions (for example, both left and right directions) with respect to the workpiece, it is possible to prevent the pressing means from becoming large.
Further, according to the present invention, the outer peripheral surface of the abutting portion moves in the workpiece conveying direction while slightly swinging in the circumferential direction of the workpiece while being restrained by the through hole of the cylindrical mold. Here, generally, when the inner cylinder fitted (restrained) in the circular hole of the outer cylinder moves in the axial direction, the inner cylinder moves in the axial direction while slightly swinging in the circumferential direction. However, the frictional force acting on the outer peripheral surface of the inner cylinder is smaller than when the inner cylinder simply moves in the axial direction. For this reason, it can prevent that the frictional force which acts on the outer peripheral surface of a butt | matching part becomes large, it becomes difficult to be damaged to an outer peripheral surface, and quality can be made favorable.

It is the schematic perspective view which showed the manufacturing apparatus of the metal circular tube in 1st Embodiment. It is a vertical side view of the welding apparatus etc. which were shown in FIG. It is a longitudinal front view of the welding apparatus etc. which were shown in FIG. FIG. 2 is a control system block diagram of the electronic control device shown in FIG. 1. It is the flowchart which showed operation | movement of the manufacturing apparatus of a metal circular tube with respect to a predetermined | prescribed butt | matching part. It is the figure which showed the state in which the volume defect has arisen in the predetermined butt | matching part. (A) It is the figure which showed transmission of the force with respect to the workpiece | work of the 1st press apparatus shown in FIG. (B) It is the figure which showed transmission of the force with respect to the workpiece | work of the conventional press apparatus. (A) It is the figure which showed the state by which the fuse | melted predetermined | prescribed butt | matching part is concave shape. (B) It is the figure which showed the state by which the fuse | melted predetermined | prescribed butt | matching part is convex shape. It is the flowchart which showed the processing content of the press position determination part shown in FIG. It is the schematic perspective view which showed the manufacturing apparatus of the metal circular tube in 2nd Embodiment. In the conventional manufacturing apparatus of a metal circular pipe, it is the schematic perspective view which showed the state by which the workpiece | work was pressed by the press means. (A) It is the schematic top view which showed the workpiece | work from which outer periphery length differs according to an axial direction. (B) It is the schematic top view which showed the workpiece | work which an abutting part wave | winds along an axial direction. (C) It is the vertical front view which showed the workpiece | work in which the level | step difference has arisen in the butt | matching part.

  Next, the manufacturing method and manufacturing apparatus of the metal circular pipe concerning this invention are demonstrated below, referring drawings. FIG. 1 is a schematic perspective view showing a metal circular pipe manufacturing apparatus 1 (hereinafter referred to as “apparatus 1”). As shown in FIG. 1, a welding device 20 that continuously welds the workpiece 10 being conveyed, a guide member 30 that guides the movement of the workpiece 10, and a pressing means 40 that locally presses the workpiece 10 are provided. ing. 2 is a longitudinal side view of the welding apparatus 20 and the like shown in FIG. 1, and FIG. 3 is a longitudinal front view of the welding apparatus 20 and the like shown in FIG.

  The workpiece 10 is obtained by pressing a thin metal plate with various roll groups and roll-forming into a cylindrical shape. For this reason, the cross-sectional shape of the workpiece 10 is substantially C-shaped, and the end portion in the circumferential direction of the workpiece 10 is a butt portion 10a. The workpiece 10 has an outer diameter of, for example, about 100 mm. This apparatus 1 conveys the workpiece | work 10 from the left side of FIG. 1 to the right side with the conveying apparatus which is not shown in figure, and it welds continuously in the state which butted | matched the butt | matching part 10a, and manufactures the metal circular pipe 10A. It has become.

  The welding apparatus 20 includes a cylindrical mold 21 for inserting the workpiece 10 and a laser welding head 22 as a welding tool for welding the workpiece 10. The cylindrical mold 21 has a rectangular parallelepiped box shape and has a circular through hole 21a through which the workpiece 10 conveyed to the center is inserted. In the upper part of the cylindrical mold 21, a guide member 30 is assembled on the inlet side in the conveyance direction of the workpiece 10 (hereinafter simply referred to as “conveyance direction”), and the laser welding head 22 is assembled at the center in the conveyance direction. It is attached. In addition, the pressing means 40 is assembled at the lower part of the cylindrical mold 21 along the conveying direction.

  The cylindrical mold 21 has a longitudinal dimension (left and right direction in FIG. 2) of about 250 mm, for example, a height direction (vertical direction of FIG. 3) of about 200 mm, and a width direction (in FIG. 3). The dimension in the left and right direction is, for example, about 280 mm. Further, the diameter of the through hole 21 a of the cylindrical mold 21 is set slightly larger than the outer diameter of the workpiece 10. The laser welding head 22 irradiates the butting portion 10a of the workpiece 10 with laser light and joins the butting portion 10a.

  The guide member 30 is for aligning the butting portion 10a in the circumferential direction. This guide member 30 is a razor-like thing, and has the blade part 30a below. As shown in FIG. 2, the blade portion 30a extends so as to have a predetermined gradient with respect to the conveyance direction, and enters the gap 10b of the abutting portion 10a on the inlet side in the conveyance direction, and exits in the conveyance direction. Then, it comes out from the clearance gap 10b of the butt | matching part 10a. In this embodiment, the thickness of the blade portion 30a is set to about 2 mm, and the gap 10b of the butt portion 10a is set to about 3 mm.

  As shown in FIG. 2, the pressing means 40 has an opposite portion 10 c (a lower portion of the workpiece 10) located on the opposite side of the abutting portion 10 a in the circumferential direction of the workpiece 10 facing the axial center O <b> 1 (see FIG. 3). Press. The pressing means 40 includes a first pressing device 41, a second pressing device 42, and a third pressing device 43 in order from the entrance side in the transport direction. As shown in FIG. 1, each pressing device 41, 42, 43 is connected to the electronic control device 50 and is configured to be driven independently.

  As shown in FIG. 2, the first pressing device 41 presses the opposite portion 10c on the inlet side in the transport direction from the welding position (the position of the tip of the laser welding head 22). 1 drive mechanism 41b. The roller follower 41a is in direct contact with the opposite portion 10c of the workpiece 10, and transmits a force in the radial direction (vertical direction in FIG. 2) to the workpiece 10 while rotating. The first drive mechanism 41b is configured to press the roller follower 41a toward the opposite portion 10c and to control the pressing load. The effect of the first pressing device 41 will be described in detail later.

  As shown in FIG. 2, the second pressing device 42 presses the opposite portion 10c on the outlet side in the transport direction from the welding position or the welding position, and has a roller follower 42a and a second drive mechanism 42b. doing. The roller follower 42a is in direct contact with the opposite portion 10c of the workpiece 10, and transmits the displacement in the radial direction (vertical direction in FIG. 2) to the workpiece 10 while rotating. The second drive mechanism 42b is configured to press the roller follower 42a toward the opposite portion 10c and to control the pressing position. The operational effects of the second pressing device 42 will be described in detail later.

  As shown in FIG. 2, the third pressing device 43 presses the opposite portion 10c on the exit side in the transport direction from the second pressing device 42, and has a roller follower 43a and a third drive mechanism 43b. doing. The roller follower 43a is in direct contact with the opposite portion 10c of the workpiece 10 and transmits a radial force (vertical direction in FIG. 2) to the workpiece 10 while rotating. The third drive mechanism 43b is configured to press the roller follower 43a toward the opposite portion 10c and to control the pressing load. The effect of the third pressing device 43 will be described in detail later.

  Next, a control system of the electronic control device 50 will be described with reference to FIG. FIG. 4 is a block diagram of the control system of the electronic control unit 50. The electronic control device 50 includes a first drive control unit 51, a second drive control unit 52, a third drive control unit 53, a jig control unit 54, and a pressing position determination unit 55. The electronic control device 50 is connected to a first laser displacement device 61 as a butt shape measurement means and a second laser displacement device 62 as a bead shape measurement means.

  The first drive control unit 51 is connected to the first drive mechanism 41b, and outputs a control signal generated based on the material, plate thickness, outer diameter, and the like of the workpiece 10 to the first drive mechanism 41b. The drive mechanism 41b is driven. The second drive control unit 52 inputs the pressing position Xf determined by the pressing position determination unit 55, outputs a control signal generated based on the pressing position Xf to the second driving mechanism 42b, and outputs the second driving mechanism 42b. Is supposed to drive. The third drive control unit 53 is connected to the third drive mechanism 43b, and outputs a control signal generated based on the material, plate thickness, outer diameter, and the like of the workpiece 10 to the third drive mechanism 43b. The drive mechanism 43b is driven. The jig control unit 54 is connected to the laser welding head 22 and a conveying device (not shown) and drives them.

  Here, the first laser displacement device 61 and the second laser displacement device 62 will be described. As shown in FIGS. 1 and 2, the first laser displacement device 61 measures the shape of the gap 10b of the butt portion 10a on the inlet side in the transport direction from the welding position. Thereby, it can measure how much the volume of the butt | matching part 10a is insufficient. As shown in FIGS. 1 and 2, the second laser displacement device 62 measures the shape of the bead of the melted butt portion 10a on the outlet side in the transport direction from the welding position or the welding position. Thereby, it is possible to measure how much the volume of the melted butted portion 10a is excessive or insufficient. The butt shape measuring means and the bead shape measuring means are not limited to the laser displacement devices 61 and 62, and may be, for example, an image processing device.

  The pressing position determination unit 55 determines the pressing position Xf of the roller follower 42a. The pressing position determination unit 55 performs feedforward control based on the measurement value F1 measured by the first laser displacement device 61 and performs feedback control based on the measurement value B1 measured by the second laser displacement device 62. Is going. The control process of the pressing position determination unit 55 will be described in detail later.

  Next, the operation of the apparatus 1 having the above configuration will be described with reference to FIG. Here, the abutting portion 10 a is a circumferential end portion of the workpiece 10 and a portion indicating the whole along the axial direction of the workpiece 10. Therefore, a predetermined portion in the axial direction of the abutting portion 10a is defined as a predetermined abutting portion 10x, and FIG.

  As shown in FIG. 5, first, conveyance of the workpiece 10 is started by a conveyance device (not shown), and the predetermined abutting portion 10 x moves toward the welding device 20 (step 1). And the 1st laser displacement apparatus 61 measures the shape of the clearance gap 10b of the predetermined butt | matching part 10x before welding (step 2). Here, FIG. 6 shows a state in which a volume defect VD is generated in the predetermined abutting portion 10x. As shown in FIG. 6, the volume defect VD is formed when the metal plate is pressed and sagging occurs on the end surface. In this step 2, an insufficient volume of the predetermined abutting portion 10x is measured, and this measured value F1 is input to the pressing position determining portion 55.

  Subsequently, the predetermined abutting portion 10x is guided by the guide member 30 (step 3). In Step 3, the predetermined abutting portion 10x advances in the transport direction from the entrance in the transport direction of the blade portion 30a of the guide member 30 in a state of being separated from the blade portion 30a (there is a gap 10b). Here, as the predetermined abutting portion 10x advances in the conveying direction, the influence of the pressing load of the first pressing device 41 on the workpiece 10 increases, and the gap 10b of the predetermined abutting portion 10x becomes narrower. Thus, the predetermined abutting portion 10x clings to the blade portion 30a from the central portion in the conveying direction of the blade portion 30a toward the outlet side. Since the blade portion 30a has a gradient as described above, the predetermined abutting portion 10x is closed and abutted on the outlet side in the conveying direction of the blade portion 30a. In this manner, the guide member 30 and the first pressing device 41 align (center) the predetermined butted portion 10x in the circumferential direction.

  And the predetermined opposite site | part 10y located in the circumferential direction of the workpiece | work 10 on the opposite side to the predetermined butt | matching part 10x is pressed by the 1st press apparatus 41 (step 4). Here, with respect to the operation and effect of the first pressing device 41, the case of pressing by the first pressing device 41 and the conventional pressing device (means) 140 (the rollers 141, 142, 143, 144 described in the above-mentioned Patent Document 1). 145, 146) will be described in comparison with the case of pressing. 7A schematically shows a case where the first pressing device 41 presses using the cylindrical mold 21, and FIG. 7B schematically shows a case where pressing is performed by the conventional pressing device 140. Show.

  First, the case where the conventional pressing device 140 presses will be described. As shown in FIG. 7B, in the conventional pressing device 140, the workpiece 110 is pressed by rollers 143 (141) and 144 (142) from the left and right. Here, it is important to abut the abutting portion 110a so that the outer peripheral surface thereof is flat. This is because, for example, when the butt portion 110a is butted in a state where a step is generated, the surface of the butt portion melted by welding does not become flat, resulting in insufficient strength of the metal circular tube and a reduction in quality.

  In the conventional pressing device 140, in order to abut the abutting portion 110a so that the outer peripheral surface thereof is flat, the pressing force and the pressing force that the left and right rollers 143 (141) and 144 (142) press against the workpiece 110 are used. The position must be equal left and right, and it is difficult to adjust the pressing force and the pressing position. In particular, when there is a manufacturing error (accuracy variation) in the workpiece 110 itself, that is, as shown in FIG. 12A, when the outer peripheral length is a workpiece 110A that differs depending on the axial direction (d1 ≠ d2), Alternatively, as shown in FIG. 12B, when the end surface of the abutting portion 110a is a workpiece 110B that undulates along the axial direction, the outer peripheral surface is flattened according to the position of the abutting portion 110a. The pressing force and the pressing position for matching are changed, and it is difficult to butt the butt portion 110a at an appropriate position.

  Further, in the conventional pressing device 140, the abutting portion 110a is pressed by the upper and lower rollers 145 and 146 from the vertical direction. Thereby, even if there is a step in the butt portion 110a as shown in FIG. 12C, this step can be eliminated. However, in this case, the frictional force acting on the outer peripheral surface of the butt portion 110a is increased, and the outer peripheral surface may be damaged and the quality may be deteriorated. Furthermore, since it is necessary to restrain the cylindrical workpiece 110 with the left and right rollers 143 (141) and 144 (142) and the upper and lower rollers 145 and 146, the outer diameter of the workpiece 110 is 1 mm from the target outer diameter. When there is an error as described above, the rollers 141, 142, 143, 144, 145, and 146 cannot be restrained, which causes the yield to deteriorate.

  On the other hand, when the 1st press apparatus 41 presses, the following effects are produced. As shown in FIG. 7A, in the first pressing device 41, the roller follower 41a presses the predetermined opposite portion 10y toward the axial center O1. As a result, the workpiece 10 is pressed in a floating state with respect to the through hole 21 a of the cylindrical mold 21, and the upper outer peripheral surface of the workpiece 10 is deformed along the through hole 21 a of the cylindrical mold 21. As described above, since the workpiece 10 is assumed to be deformed, as shown in FIG. 12A, when the outer peripheral length is a workpiece 110A different depending on the axial direction, or shown in FIG. 12B. As shown in FIG. 12C, the end surface of the abutting portion 110a is a wavy workpiece 110B, or as shown in FIG. 12C, the abutting portion 110a has a step 110C. However, the outer peripheral surface of the predetermined abutting portion 10x can be flexibly deformed, and the predetermined abutting portion 10x can be abutted so that the outer peripheral surface is flat.

  Incidentally, as shown in FIG. 7A, the pressing force of the roller follower 41a is transmitted from the predetermined opposite portion 10y toward the predetermined abutting portion 10x as indicated by an arrow. Then, a reverse pressing force acts in the circumferential direction of the workpiece 10 at the predetermined abutting portion 10x, and the predetermined abutting portion 10x slightly swings in the circumferential direction of the workpiece 10. As a result, the outer peripheral surface of the predetermined abutting portion 10x is restrained by the through hole 21a of the cylindrical mold 21 and is slightly swung in the circumferential direction of the workpiece 10, while the workpiece 10 is conveyed by a conveying device (not shown). Move in the direction. Here, generally, when the inner cylinder fitted (restrained) in the circular hole of the outer cylinder moves in the axial direction, the inner cylinder moves in the axial direction while slightly swinging in the circumferential direction. However, the frictional force acting on the outer peripheral surface of the inner cylinder is smaller than when the inner cylinder simply moves in the axial direction. From this, in the case of pressing with the first pressing device 41 using the cylindrical mold 21, the frictional force acting on the outer peripheral surface of the predetermined abutting portion 10 x is larger than when pressing with the conventional pressing device 140. It can be prevented from becoming large, the outer peripheral surface is hardly damaged, and quality can be prevented from deteriorating.

  Further, as shown in FIG. 7A, the workpiece 10 is locally pressed while being deformed by the first pressing device 41 and is pressed by the conventional pressing device 140, so that the entire workpiece 10 is It is not pressed while the shape is constrained. Therefore, even when the outer diameter of the workpiece 10 is larger or smaller than the target outer diameter by 1 mm or more, in other words, even if the dimensional accuracy of the outer diameter of the roll-formed workpiece 10 is low, the workpiece 10 is a cylinder. If it is inserted through the through hole 21a of the metal mold 21, the predetermined abutting portion 10x can be abutted so that the outer peripheral surface thereof is flat, and deterioration of the yield can be prevented.

  As shown in FIG. 7A, since the workpiece 10 is pressed in a floating state with respect to the through hole 21a of the cylindrical mold 21, the cross section of the through hole 21a of the cylindrical mold 21 is It is considered that the upper half may be a semicircle instead of a circle. However, when the cross section of the through hole 21a of the cylindrical mold 21 is an upper half semicircle, the workpiece 10 may be excessively deformed and the cross section may have a chestnut shape. For this reason, the cross-section of the through hole 21a of the cylindrical mold 21 needs to be circular, and excessive deformation of the work can be prevented by the lower half of the through hole 21a.

  Here, it returns to the flowchart of FIG. After the pressing by the first pressing device 41, the laser welding head 22 starts welding the predetermined butt portion 10x (step 5). In step 5, based on a command from the jig control unit 54, the laser is irradiated from the laser welding head 22 toward the predetermined abutting portion 10x, and the predetermined abutting portion 10x is melted. By the way, the workpiece 10 is deformed by volume expansion when the molten metal solidifies, volume change due to transformation of a non-molten portion, and expansion / contraction due to temperature change. For this reason, the surface of the melted predetermined abutting portion 10x does not become flat but becomes convex or concave.

  In particular, as shown in FIG. 6, when a volume defect VD occurs in the predetermined abutting portion 10x, the surface of the melted predetermined abutting portion 10x becomes concave as shown in FIG. 8A. Further, even when the load with which the predetermined abutting portion 10x is abutted is small, as shown in FIG. 8A, the surface of the melted predetermined abutting portion 10x becomes concave. On the other hand, when the load with which the predetermined abutting portion 10x is abutted is large, as shown in FIG. 8B, the surface of the melted predetermined abutting portion 10x becomes convex. FIG. 8 is a cross-sectional view showing the surface state of the melted predetermined butt portion 10x. Here, generally, the welding conditions are managed so that the surface of the melted predetermined butt portion 10x is flat. However, since the shape of the end face of the butt portion 10a, the welding environment, and the like are not always constant, it is difficult to flatten the surface of the predetermined butt portion 10x that is stably melted even if the welding conditions are strictly controlled.

  Therefore, in this device 1, the surface of the molten predetermined butt portion 10x is made flat (upset) with high accuracy by shaping the molten predetermined butt portion 10x using the second pressing device 42. Here, since the pressing position Xf of the roller follower 42a by the second pressing device 42 is determined by the pressing position determination unit 55, the processing content of the pressing position determination unit 55 will be described with reference to the flowchart of FIG. The pressing position determination unit 55 starts and executes a program based on the flowchart shown in FIG. 9 every elapse of a predetermined time (for example, 5 msec).

  As shown in FIG. 9, first, the pressing position determination unit 55 determines the temporary pressing position Xa of the roller follower 42a based on the preset material, plate thickness, outer diameter, etc. of the workpiece 10 (step 61). . Next, the pressing position determination unit 55 inputs the measurement value F1 measured by the first laser displacement device 61, that is, the insufficient amount of the volume of the butt portion 10a (step 62). The input measurement value F1 is an insufficient amount of the volume of the abutting portion 10a located on the inlet side in the transport direction from the predetermined abutting portion 10x, and is a value that is fed forward. Further, the pressing position determination unit 55 inputs the measurement value B1 measured by the second laser displacement device 62, that is, the volume of the bead of the molten butt 10a (step 62). The input measurement value B1 is the volume of the bead of the molten butt portion 10a located on the outlet side in the transport direction from the molten predetermined butt portion 10x, and is a value fed back.

  Next, the pressing position determination unit 55 calculates the first correction amount Fa for the temporary pressing position Xa based on the measured value F1 (step 63). And the press position determination part 55 determines the 1st correction press position Xb which is the value which considered the 1st correction amount Fa to the temporary press position Xa (step 64). Specifically, when the volume defect VD occurs in the abutting portion 10a (see FIG. 6), the pressing position determination unit 55 adjusts the pressing position of the roller follower 42a to a position where a larger pressing force is applied. In this way, the feedforward control is performed based on the shortage of the volume of the butt portion 10a, thereby preventing the surface of the melted predetermined butt portion 10x from becoming concave.

  Subsequently, the pressing position determination unit 55 calculates a second correction amount Ba for the first correction pressing position Xb based on the measured value F2 (step 65). Then, the pressing position determination unit 55 determines a pressing position (second correction pressing position) Xf that is a value in consideration of the second correction amount Ba for the first correction pressing position Xb (step 65). Specifically, when the volume of the melted butted portion 10a is insufficient (see FIG. 8A), the pressing position determination unit 55 applies a larger pressing force to the pressing position of the roller follower 42a. Adjust to position. Further, when the volume of the bead of the melted butting portion 10a is excessive (see FIG. 8B), the pressing position determination unit 55 applies a smaller pressing force to the pressing position of the roller follower 42a. Adjust to. Thus, feedback control is performed based on the volume of the bead of the melted butted portion 10a, thereby preventing the surface of the melted predetermined butted portion 10x from becoming concave or convex.

  Thus, after determining the pressing position Xf, the pressing position determination unit 55 outputs a control signal generated based on the pressing position Xf to the second driving mechanism 42b to drive the second driving mechanism 42b (step 67). . Thereby, the roller follower 42a moves so that the position becomes the pressing position Xf, and presses the predetermined opposite portion 10y. Then, the pressing position determination unit 55 determines whether or not the surface of the melted predetermined abutting portion 10x is flat (step 68). When the surface of the melted predetermined abutting portion 10x is flat, the pressing position determining unit 55 determines “Yes” because it is not necessary to correct the pressing position Xf, and the program is temporarily terminated. On the other hand, when the surface of the melted predetermined abutting portion 10x is not flat, the pressing position determination unit 55 determines “No” because it is necessary to correct the pressing position Xf, and repeats steps 62 to 68. To do. In this way, the second pressing device 42 can accurately flatten (upset) the surface of the melted predetermined abutting portion 10x. The cylindrical mold 21 is provided with a laser displacement device or an image processing device (not shown) for measuring the surface shape of the melted predetermined abutting portion 10x.

  Here, it returns to the flowchart of FIG. After pressing by the second pressing device 42, the predetermined opposite portion 10y is pressed by the roller follower 43a of the third pressing device 43 (step 7). In step 7, a load is applied in the abutting direction at the melted predetermined abutting portion 10x by the pressing of the third pressing device 43, and the molten predetermined abutting portion 10x is prevented from solidifying in a separated state. That is, the melted predetermined abutting portion 10x is easily separated unless a load is applied in the abutting direction, and the predetermined abutting portion 10x melted by the third pressing device 43 can be maintained in a continuous state. Yes. Finally, the second laser displacement device 62 measures the shape of the melted bead of the predetermined abutting portion 10x, and this measured value B1 is input to the pressing position determining portion 55 (step 8). In this way, the operation of the device 1 with respect to the predetermined matching portion 10x is completed.

The effect of this embodiment is demonstrated.
According to the metal circular pipe manufacturing apparatus and manufacturing method in this embodiment, the workpiece 10 is pressed in a floating state with respect to the through hole 21a of the cylindrical mold 21, and the outer peripheral surface on the upper side of the workpiece 10 is a cylinder. It deforms along the through hole 21a of the metal mold 21. As described above, since the outer peripheral surface of the workpiece 10 is assumed to be deformed, even if there is a manufacturing error (accuracy variation) in the workpiece 10 itself, the outer peripheral surface of the abutting portion 10a is flexibly deformed to 10a can be abutted so that the outer peripheral surface is flat.

  Further, according to this embodiment, the pressing devices 41, 42, and 43 press the opposite portion 10 c toward the axial center O <b> 1 of the workpiece 10. For this reason, the pressing devices 41, 42, and 43 press the workpiece 10 from one direction, and do not press from multiple directions like the conventional pressing device 140 (see FIG. 7B). Therefore, it is possible to prevent the pressing operation of the drive mechanisms 41b, 42b, and 43b that drive the roller followers 41a, 42a, and 43a from becoming complicated. Further, the pressing devices 41, 42, and 43 are disposed only below the workpiece 10. For this reason, the pressing devices 41, 42, and 43 are not arranged at multi-directional positions with respect to the workpiece 10 as in the conventional pressing device 140 (see FIG. 7B), but the large size of the pressing device. Can be prevented.

  Further, according to this embodiment, the outer peripheral surface of the abutting portion 10 a moves in the transport direction while slightly swinging in the circumferential direction of the workpiece 10 while being restrained by the through hole 21 a of the cylindrical mold 21. . Here, generally, when the inner cylinder fitted (restrained) in the circular hole of the outer cylinder moves in the axial direction, the inner cylinder moves in the axial direction while slightly swinging in the circumferential direction. However, the frictional force acting on the outer peripheral surface of the inner cylinder is smaller than when the inner cylinder simply moves in the axial direction. For this reason, it can prevent that the frictional force which acts on the outer peripheral surface of the butt | matching part 10a becomes large, it becomes difficult to damage a peripheral surface, and quality can be made favorable.

  Next, a second embodiment will be described with reference to FIG. In the first embodiment, the continuous metal circular pipe 10A is manufactured by continuous pipe forming, but in the second embodiment, the short pipe 70A is manufactured by pipe forming for each required length. . In 2nd Embodiment, the same code | symbol is attached | subjected about the same member as 1st Embodiment, and only a different part from 1st Embodiment is demonstrated.

  The work 70 has an axial length of 500 mm or less, and the short pipe 70 </ b> A is manufactured by welding the butting portion 70 a of the work 70 with the welding device 20. In the second embodiment, as shown in FIG. 10, a pressing device 80 is provided at the same position as the welding position in the transport direction. Thus, unlike the first embodiment, there is one pressing device, and the reason will be described below.

First, in the first embodiment, the workpiece 10 to be conveyed is longer than the workpiece 70 of the second embodiment, and extends continuously. For this reason, in the butt | matching part 10a, the difference of the rigidity which tries to spread in the circumferential direction is large between the part in which welding has already been completed, and the part in which welding has not been completed yet. In the first embodiment, it is preferable to include the first pressing device 41 from the viewpoint of suppressing an adverse effect based on the difference in rigidity.
On the other hand, in the second embodiment, since the axial length of the work 70 to be conveyed is 500 mm or less, the work 70 is short. For this reason, in the butt | matching part 70a, the difference of the rigidity which tries to spread in the circumferential direction is small between the part which has already completed welding, and the part which has not yet completed welding. Therefore, since the adverse effect based on the difference in rigidity is small, it is not necessary to provide a pressing device corresponding to the first pressing device 41.
Further, the third pressing device 43 of the first embodiment is for maintaining a state in which the molten butted portion 10a is continuous, and can be appropriately omitted depending on welding conditions such as the material of the workpiece, the outer diameter, and the plate thickness. Is.
Based on such a reason, in the second embodiment, there is one pressing device.

  In this 2nd Embodiment, since there is one press apparatus, a press apparatus can be comprised compactly and cheaply. Other operational effects are substantially the same as those in the first embodiment, and thus the description thereof is omitted.

As mentioned above, although the manufacturing apparatus and manufacturing method of the metal circular pipe concerning this invention were demonstrated, this invention is not limited to this, A various change is possible in the range which does not deviate from the meaning.
For example, in the first embodiment, the first pressing device 41, the second pressing device 42, and the third pressing device 43 are provided as the pressing means 40. However, the third pressing device 43 may not be provided. Either one of the device 41 and the second pressing device 42 may not be provided.
In the second embodiment, only the pressing device 80 is provided as the pressing means. However, a pressing device corresponding to the first pressing device 41 or a device corresponding to the third pressing device 43 may be provided.
Moreover, in each embodiment, although the guide member 30 which has the blade part 30a was used as a guide means which aligns the circumferential direction of the butting | matching part 10a, the structure of a guide means can be changed suitably. Further, the guide means may not be provided.
Moreover, in each embodiment, although laser welding was illustrated, this invention is applicable also to welding methods other than a laser (for example, MIG, MAG, TIG, plasma welding etc.).

DESCRIPTION OF SYMBOLS 1 Metal circular pipe manufacturing apparatus 10 Work 10A Metal circular pipe 10a Butting part 10b Gap 10c Opposite part 10x Predetermining confronting part 10y Predetermining opposite part 20 Welding device 21 Cylindrical metal mold 21a Through hole 30 Guide member 30a Blade part 40 Pressing means 41 First pressing device 42 Second pressing device 43 Third pressing device 50 Electronic control device 55 Pressing position determination unit 61 First laser displacement device 62 Second laser displacement device 70 Work 70A Short tube 80 Pressing device

Claims (10)

In a manufacturing apparatus of a metal circular pipe that is welded using a welding tool in a state of butting a butting portion that is a circumferential end portion of a workpiece that is roll-formed into a cylindrical shape and conveyed,
A cylindrical mold having a through hole with a hole diameter slightly larger than the outer diameter of the workpiece;
In a state where the workpiece is inserted through the through hole of the cylindrical mold, a pressing unit that presses an opposite portion located on the opposite side of the butting portion in the circumferential direction of the workpiece toward the axial center of the workpiece, equipped with a,
It said pressing means has a plurality of pressing devices, apparatus for producing metallic circular tube, characterized in Rukoto are arranged at different positions in the conveying direction of the workpiece. In the manufacturing apparatus of the metal circular pipe of Claim 1,
The pressing means includes a first pressing device that presses the opposite portion on the entrance side in the workpiece conveyance direction from the welding position of the welding tool to abut the abutting portion. manufacturing device. In the metal tube manufacturing apparatus according to claim 1 or 2,
The pressing means includes a second pressing device that shapes the butted portion that is melted by pressing the opposite portion at a welding position of the welding tool or an outlet side in the workpiece conveyance direction from the welding position. Metal circle pipe manufacturing equipment. In the metal circular pipe manufacturing apparatus according to claim 3,
A butt shape measuring means for measuring the shape of the gap of the butt portion on the inlet side in the conveying direction of the workpiece from the welding position;
A bead shape measuring means for measuring the shape of the melted bead of the butt portion on the outlet side in the conveying direction of the workpiece from the welding position or the welding position;
An electronic control unit that determines a pressing position at which the second pressing device presses the opposite portion based on the measurement values of the butt shape measuring unit and the bead shape measuring unit, and controls the driving of the second pressing device; An apparatus for producing a metal circular tube, comprising: In the manufacturing apparatus of the metal circular pipe of Claim 3 or Claim 4,
The pressing means includes a third pressing device that maintains a continuous state of the butt portion melted by pressing the opposite portion on the outlet side in the conveyance direction of the workpiece from the second pressing device. Manufacturing equipment for metal tubes. In the manufacturing apparatus of the metal circular tube in any one of Claims 1 thru | or 5,
Guide means for aligning the butting portion in the circumferential direction,
The guide means extends so as to have a predetermined gradient with respect to the workpiece conveying direction, enters the gap of the abutting portion on the inlet side in the workpiece conveying direction, and the abutting on the outlet side in the workpiece conveying direction. An apparatus for manufacturing a metal circular tube, comprising a blade portion that comes out of a gap between the portions. In a method of manufacturing a metal circular pipe that is welded using a welding tool in a state in which a workpiece roll-formed in a cylindrical shape is conveyed in the axial direction, and a butted portion that is a circumferential end portion of the workpiece is butted.
For a cylindrical mold having a through-hole, a conveying step of inserting and conveying a workpiece having an outer diameter slightly smaller than the diameter of the through-hole through the through-hole,
Press for pressing an opposite portion located on the opposite side of the abutting portion in the circumferential direction of the workpiece toward the axial center of the workpiece by pressing means including a plurality of pressing devices arranged at different positions in the workpiece conveying direction. A method of manufacturing a metal circular tube. In the manufacturing method of the metal circular pipe according to claim 7,
In the pressing step, the opposite portion is pressed against the welding position of the welding tool on the inlet side in the workpiece conveyance direction so as to abut the butted portion. In the manufacturing method of the metal circular pipe of Claim 7 or Claim 8,
In the pressing step, the welding portion of the welding tool or the outlet side in the workpiece conveyance direction from the welding position, the opposite portion is pressed and melted to shape the butt portion. Production method. In the manufacturing method of the metal circular tube in any one of Claims 7 thru | or 9,
In the said conveyance process, the workpiece | work whose axial direction length is 500 mm or less is conveyed, The manufacturing method of the metal circular pipe characterized by the above-mentioned.

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