JP6138213B2 - Welding apparatus for work to be welded having a large number of welding points and method of using the same - Google Patents

Description

  The present invention relates to an apparatus for welding an object to be welded having a large number of welding points, such as welding between a tube plate of a multi-tubular cylindrical heat exchanger and a heat transfer tube end, and a method of using the apparatus.

  In a multi-tube cylindrical heat exchanger used in industrial air conditioning equipment, electronics industry, pharmaceutical, food industry plants, etc., a large number of heat transfer tubes are arranged in the cylindrical fuselage, and tube plates provided at both ends of the cylindrical fuselage The end of the heat transfer tube is passed through the tube hole and the periphery of the end is welded to the tube plate. Performing the welding manually is cumbersome and automated.

  Automation of welding work is realized by various methods. For example, in the apparatus described in Patent Document 1, a reference image of a tube plate surface prepared in advance and a CCD fixed at a position where the tube plate surface can be photographed. A camera, a torch rotating mechanism, and a moving mechanism in the X and Y directions for correcting the torch position are provided. In order to perform the welding operation with this apparatus, first, the body of the heat exchanger to be welded is gripped by the apparatus, the CCD camera is set to a narrow field of view, and an image of the tube sheet surface is taken. Compared with the reference image, the amount of misalignment between the tube hole of the tube plate and the tube hole of the master image is obtained, and the end of the heat transfer tube inserted into the tube hole is corrected after the torch position is corrected by the torch moving mechanism. The periphery is welded to the tube sheet. When the welding of one tube hole is completed, the CCD camera is switched to a wide field of view, a plurality of tube holes are photographed, the positions of adjacent tube holes are determined, and the torch is moved to a predetermined position for welding. . This operation is repeated to weld a plurality of tube holes sequentially.

  However, in this method, the torch is moved to a number of tube hole positions provided on the fixed tube plate, and welding is performed around each tube hole, so the torch cable and welding wire are bent in a complicated manner. In some cases, a stable welding wire cannot be supplied, which may affect the welding quality. In the heat exchanger, since thermal expansion and contraction are repeated, if the welding is not uniform, stress concentration is partially generated and may be damaged.

JP 2000-9427 A

  The present invention is a welding that can solve the problems in a welding apparatus that performs welding on an object to be welded having a large number of parts to be welded, such as welding to a tube sheet at the end of a conventional heat transfer tube as described above. An apparatus and method of use thereof are provided.

That is, the present invention
In a work piece having a surface having a number of points to be welded, welding to the point is performed along a circle with a constant radius centering on each axis passing through each point to be welded and extending in a direction perpendicular to the surface. Performing a welding device,
The work piece is held in a predetermined position in the welding apparatus so as to be rotatable around a rotation axis extending perpendicularly to the surface, and an arbitrary place among the places where the work piece is welded is provided. A workpiece holding device capable of being displaced parallel to the plane so that the axis passing therethrough coincides with the rotational axis;
A weld with a torch that can be set at a position adjacent to the axis of rotation;
A constant radius around the axis passing through the arbitrary position by the torch by rotating the workpiece around the rotational axis in a state where the axis passing through the arbitrary position coincides with the rotational axis. There is provided a welding apparatus for an object to be welded having a large number of welding points, which performs welding along a circle.
In this welding apparatus, since the workpiece is rotated while the torch is held at a fixed position, it is possible to solve the problems of the conventional welding apparatus as described above.

In particular,
The welding object holding device includes:
A rotating support made rotatable about the rotation axis;
Provided on the rotary support, holds the workpiece, and is displaceable in parallel to a plane perpendicular to the rotational axis, so that the axis passing through the welding point can be aligned with the rotational axis. Means for holding the workpiece,
It can be made to have.

More specifically,
The workpiece holding means includes a first linear displacement member attached to the rotary support and capable of being displaced in one direction orthogonal to the rotation axis within a plane orthogonal to the rotation axis; A second linear displacement member attached to the first linear displacement member and displaceable in a direction orthogonal to the displacement direction of the first linear displacement member within the plane; and the welded workpiece attached to the second linear displacement member And a clamp member for gripping an object.

The welding apparatus is further set to a reference position in the welding apparatus, and is displaceable in parallel to a plane perpendicular to the rotation axis of the rotary support, and passes from the reference position through the welding position. Having a probe that determines the distance from the reference position to the axis of the welded point by displacing to the position of the axis;
Based on the position of the axis passing through the welding location determined from the determined distance with respect to the rotational axis of the rotary support, the workpiece holding means changes the axis passing through the welding location to the rotational axis. The work piece can be moved to align.

In particular,
The workpiece is a tube sheet of a heat exchanger having end portions of heat transfer tubes inserted into a number of tube holes provided on the surface,
The work-piece holding means is adapted to hold a cylindrical body having the tube sheet at its end,
The probe has a tapered tip portion extending toward the face of the tube plate, and the tip portion is inserted into the end of the heat transfer tube to be welded so that the center axis of the probe is welded. Displacement so as to coincide with the central axis of the heat pipe, and a welding apparatus for the tube sheet of the heat exchanger which determines the distance from the reference position to the central axis of the heat transfer pipe to be welded by displacing so as to coincide It can be.

  Further, the workpiece holding means calculates the rotation of the center axis of the other pipe based on the position of the center axis of the other pipe with respect to the rotation axis of the rotary support, which is calculated based on the determined distance. It is possible to sequentially align with the rotation axis of the support.

In the present invention, when used as a welding apparatus for the tube sheet of the heat exchanger,
Aligning the central axis of the probe at the reference position with the rotational axis of the rotating support;
One end of the heat transfer tube to be welded is on a vertical line passing through the central axis of the tube sheet on the tube sheet reference drawing (the drawing showing the positions and distances of many tube holes provided in the tube sheet). Suppose it was inserted into the hole,
The cylindrical body is moved by a distance in the horizontal direction in a plane perpendicular to the rotational axis of the rotary support between the central axis of the cylindrical body held by the workpiece holding means and the central axis of the probe. Move horizontally parallel to the same plane so that the vertical line passing through the central axis of the cylindrical body passes through the central axis of the probe,
By moving the cylindrical body vertically by a distance perpendicular to the center axis of the end of the heat transfer tube to be welded on the reference drawing and the center axis of the probe, the heat transfer tube to be welded on the reference drawing Make sure that the center axis of the end matches the center axis of the probe,
The deviation of the actual position of the end of the heat transfer tube to be welded in the end plate of the cylindrical body held by the workpiece holding means at this time is specified from the position on the reference drawing, and the workpiece is based on this deviation. Identify the inclination of the cylindrical body being held by the holding means relative to the central axis of the cylindrical body;
Thus, a welding method is provided in which the position of the end of another heat transfer tube relative to the rotation axis of the rotary support is specified, and the end of the other heat transfer tube is sequentially welded.
In this method of the present invention, by specifying the position of one heat transfer tube end portion to be welded by a probe, the positions of all other heat transfer tube end portions can be specified, and the end portions can be welded. It becomes. Therefore, according to this method, each time the welding of one tube hole, which has been required in the conventional welding described above, is completed, the CCD camera is switched to a wide field of view and a plurality of tube holes are photographed. Therefore, it is not necessary to perform the troublesome work of determining the position of the tube hole and moving the torch by a predetermined position to perform welding, and each welding can be performed accurately.

  Hereinafter, based on the attached drawing which showed the welding apparatus of the to-be-welded object which has many welding locations concerning the present invention as a welding apparatus which welds the end part of a heat exchanger tube in the tube sheet of the heat exchanger as one embodiment The present invention will be described.

It is a top view of the heat exchanger tube end welding device for welding the heat exchanger tube end part in the tube sheet of the heat exchanger as one embodiment of the welding device concerning the present invention. It is a left view of the heat exchanger tube end welding device shown in FIG. It is a front view of the holding | grip apparatus of the heat exchanger tube end welding apparatus shown in FIG. It is a rear view of the holding | gripping apparatus shown in FIG. It is a top view of the welding part of the heat exchanger tube end welding apparatus shown in FIG. It is a front view of the welding part shown in FIG. It is an enlarged front view of the torch unit in the weld part shown in FIG. It is a left view of the torch unit shown in FIG. FIG. 6 is an enlarged plan view of a torch unit in the weld portion shown in FIG. 5. It is a figure which shows the relationship between the torch unit in the welding operation in the heat exchanger tube end welding apparatus shown in FIG. 1, and the heat exchanger to be welded. It is an enlarged front view of the probe unit in the heat exchanger tube end weld part shown in FIG. It is a left view of the probe unit shown in FIG. It is a top view of the probe unit shown in FIG. It is a figure which shows the relationship between a probe unit and a heat exchanger in the case of performing centering of the heat exchanger tube which welds in the heat exchanger tube end welding apparatus shown in FIG. It is a figure for demonstrating the position correction amount detection for performing centering of a heat exchanger tube. FIG. 2 is a perspective view of the heat transfer tube end welding device of FIG.

As shown in the drawing, a heat transfer tube end welding device 1 according to an embodiment of the present invention holds both ends of a cylindrical body 2 of a heat exchanger, and left and right holding devices 100 that rotate the cylindrical body 2. And a welded part 200 provided adjacent to the left holding device 100, and the welded part 200 is provided in a tube hole 3a provided in the tube plate 3 at the left end of the cylindrical body 2 (FIG. 10). The end portion 4a of the heat transfer tube 4 passed through is welded to the tube plate 3.
[Holding device 100]

  The left and right holding devices 100 basically have the same structure, and will be described below with reference to the left holding device 100 as viewed in FIG. As shown in FIGS. 3 and 4, the holding device 100 has a rectangular shape as a whole as viewed in FIGS. 3 and 4 set on the base 110 installed at the installation location of the heat transfer tube end welding device 1. Main body 111 and a rotating support body 112 provided with gear teeth 112a (FIG. 4) along the inner periphery in a ring shape rotatably provided in a through-opening 111a provided so as to be largely opened in the main body 111. A generally rectangular support base 113 fixed to the rotary support 112, a first linear displacement member 115 provided on the support base 113 via a guide rail 114 so as to be movable in the vertical direction as viewed in the figure, The first linear displacement member 115 has a second linear displacement member 119 provided so as to be movable in the horizontal direction as viewed in the figure through the guide rail 118. The first linear displacement member 115 is connected to a servo motor 117 fixed to a rectangular support base 113, and is movable in the vertical direction by driving the servo motor 117. The second linear displacement member 119 can be moved in the horizontal direction by a servo motor 122. The second linear displacement member 119 includes clamp members 121a and 121b, and by rotating the handle 120, the cylindrical body 2 of the heat exchanger can be gripped and released by the clamp members 121a and 121b. It has become. Therefore, the holding device 100 can displace the cylindrical body 2 in a plane perpendicular to the central axis thereof by the servo motor 117 and the servo motor 122 while holding the end of the cylindrical body 2. It has become.

As shown in FIG. 4, a motor base 123 is fixed to the back surface of the main body 111 of the holding device 100, and a servo motor 124 and a bevel gear box 125 connected to the output shaft of the servo motor 124 are attached to the motor base 123. Is provided. The output shaft of the bevel gear box 125 extends horizontally into the rotary support 112, and has a pinion (not shown) that engages with the gear teeth 112a of the rotary support 112 at the tip, and by driving the servo motor 124, The rotary support 112 is rotated.
[Welding part 200]

As shown in FIGS. 5 and 6, the welding part 200 includes a gantry 201, a torch unit 210, and a probe unit 250, and the torch unit 210 and the probe unit 250 are movable along a guide rail 202 on the gantry 201. It is fixed on the weld base 204. The torch unit 210 performs TIG welding, and the probe unit 250 is for specifying the position of the heat transfer tube 4 to be welded before performing TIG welding. As shown in the figure, the weld base 204 is held by the air cylinder 203, the torch unit 210 is locked by the stopper 205b, and the torch unit 210 is opposed to the tube plate 3, and the stopper 205a is locked by the probe unit 250. It is displaced between the position facing the plate 3.
[Torch unit 210]

  The torch unit 210 includes a welding base frame 211 fixed on the welding base 204, a front / rear reference position setting sliding body 214 slidably attached to the welding base frame 211 in the front / rear direction, and a front / rear direction to the welding base frame 211. A lower support 218 that is slidably mounted on the lower support 218, an intermediate support 220 that is slidably mounted on the lower support 218 in a vertical direction, and a slidably mounted on the intermediate support 220 in the front-rear direction. An upper support 222 and a torch support 210 </ b> A attached to the upper support 222 and supporting the torch 230. Details will be described below.

As shown in FIGS. 7 and 8, the torch support portion 210 </ b> A includes a plate-like vertical support member 229 that supports the torch 230 and a horizontal surface that supports the vertical support member 229 and is set to be substantially horizontal. It has a support member 228 and a vertical adjustment unit 226 connected to the horizontal support member 228 via an L-shaped bracket 227, and the vertical adjustment unit 226 is supported by the front-rear adjustment unit 225. The torch 230 is connected to be displaceable along an arcuate hole 229a provided in the vertical support member 229, and the vertical support member 229 is displaceable along an arcuate hole 228a provided in the horizontal support member 228. And the mounting angle of the torch 230 is adjustable. The vertical adjustment unit 226 displaces the L-shaped bracket 227 in the vertical direction by the adjustment screw 226A, and the front-rear adjustment unit 225 displaces the vertical adjustment unit 226 in the front-rear direction by the adjustment screw 225A. Is used to displace the torch in the up-down and front-back directions. The upper support 222 is displaced by a horizontal air cylinder 224 provided on the intermediate support 220 between a front torch position for TIG welding without using a filler and a rear torch position when using a filler. It is possible. The intermediate support 220 is attached to the lower support 218 via the vertical air cylinder 221, and is displaced in the vertical direction by driving the vertical air cylinder 221 depending on the diameter of the heat transfer tube 4 to be welded. The tip can be adjusted to an appropriate welding height. The front / rear reference position setting sliding body 214 includes a vertical air cylinder 216 and a stopper 215, and is displaced in the front / rear direction by a horizontal air cylinder 213 fixed to the welding base frame 211. The lower support 218 is displaced in the front-rear direction by a horizontal air cylinder 219 fixed to the weld base frame 211. A stopper 217 is provided on the bottom surface of the lower support 218. When the lower support 218 is advanced by the horizontal air cylinder 219 in a state where the rod of the vertical air cylinder 216 is extended upward, the stopper is fixed to the rod. 217 is engaged and its advance is stopped.
[Probe unit 250]

  The probe unit 250 includes a probe base 251 fixed on the weld base 204, a horizontal guide rail 252 provided on the probe base 251 so as to extend in the front-rear direction, and a front-rear sliding body 253 guided by the horizontal guide rail 252. The horizontal air cylinder 254 moves the front / rear sliding body 253 back and forth along the horizontal guide rail 252.

  The front / rear sliding body 253 includes a horizontal guide rail 256 fixed to the front surface (the surface facing the tube plate 3), stoppers 255 a and 255 b provided adjacent to both sides of the horizontal guide rail 256, and the horizontal guide rail 256. And a horizontal sliding body 257 that can be moved horizontally in parallel with the tube sheet 3. The horizontal sliding body 257 is positioned at an intermediate point between the stoppers 255a and 255b when an external force is not applied by a spring (not shown).

  The horizontal sliding body 257 includes a vertical guide rail 259 fixed to the front surface thereof, a stopper 258a and a stopper 258b fixed to the front surface of the horizontal sliding body 257 at positions adjacent to both ends of the vertical guide rail 259, and a vertical guide rail. 259, and a vertical sliding body 260 that is vertically movable in parallel to the tube plate 3. The probe 261 is provided so as to protrude forward from the center position of the vertical sliding body 260. The distal end portion 260 a of the probe 260 is tapered, and the center of the distal end is on the central axis of the probe 260. The vertical sliding body 260 is positioned at an intermediate point between the stoppers 258a and 258b when an external force is not applied by a spring (not shown).

Further, the front / rear sliding body 253 includes a sensor 262 so that the distance in the horizontal direction from the left side surface of the vertical sliding body 260 can be measured. Further, the horizontal sliding body 257 has a sensor 263 so that a distance in the vertical direction between the horizontal sliding body 257 and the upper surface of the plate 260 can be measured.
[Probe operation]

The probe unit 250 is operated as follows.
First, the weld base 204 is positioned so that the probe unit 250 is located at a position facing the tube sheet 3 held by the holding device 100. At this time, it is preferable that the center axis of the probe 261 coincides with the rotation center axis of the rotary support 112.
The servo motor 117 and the servo motor 122 are driven so that the center axis of the end portion 4a of the heat transfer tube 4 to be welded is substantially at the same position as the center of the tip of the probe 261.
Thereafter, the front / rear sliding body 253 is advanced by the horizontal air cylinder 254, and the tapered tip end portion 261 a of the probe 261 is inserted into the heat transfer tube 4. When the center axis of the heat transfer tube 4 before being inserted does not coincide with the tip center (center axis) of the probe 261, the probe 261 has its center axis aligned with the center axis of the heat transfer tube 4 by the action of the tapered tip portion 261a. And the horizontal sliding body 257 and the vertical sliding body 260 move in the horizontal and vertical directions, respectively.
The moving distances of the horizontal sliding body 257 and the vertical sliding body 260 are measured by the sensor 262 and the sensor 263, so that the horizontal displacement x and the vertical displacement y of the center of the tip of the probe 261 are known. At this time, if the position of the center axis of the probe 261 before being inserted into the heat transfer tube 4 with respect to the rotation axis of the rotary support 112 is specified, the position of the center axis of the probe 261 and the displacement of x and y described above. Thus, the positional relationship between the center axis of the heat transfer tube 4 and the rotation axis of the rotary support 112 is understood, and the center axis of the heat transfer tube 4 is rotated by driving the servo motor 117 and the servo motor 122 of the holding device 100 accordingly. It can be made to coincide with the rotation axis of the support 112. As a specific example, if the central axis of the probe 261 before being inserted into the heat transfer tube 4 is aligned with the rotational axis of the rotary support 112, the servo of the holding device 100 can be used. By driving the motor 117 and the servo motor 122 so that the displacements x and y become zero, the center axis and the rotation axis can be matched. Therefore, if the rotating support 112 is rotated with the torch 230 positioned adjacent to the end of the heat transfer tube 4 after doing so, the end of the heat transfer tube 4 is rotated around the rotation axis of the support 112, The end portion can be welded to the tube sheet 3.

Further, as shown in FIG. 15, the central axis c of the cylindrical body 2 held by the holding device 100, the position of the probe 261 set on the rotation axis of the rotary support 112, and the holding device 100 hold the same. The position of the other heat transfer tube from the rotation axis of the rotary support 112 is specified by specifying the relationship with the end 4c ′ of the heat transfer tube 4 to be welded in the tube plate 3 of the cylindrical body 2 Therefore, these other heat transfer tubes can be welded in sequence with this rotational axis.
The position is specified as follows.
First, the center axis of the probe 261 before being inserted into the heat transfer tube 4 is made to coincide with the rotation axis of the rotary support 112, and the end 4a of the heat transfer tube 4 to be welded is referred to as a reference drawing of the tube plate 3. Inserted in a tube hole on a vertical line passing through the central axis of the tube plate 3 (and hence the central axis of the cylindrical body 2) on the drawing (the drawing showing the positions and distances of a large number of tube holes 3a provided in the tube plate 3) Suppose that X direction (horizontal direction) in a plane perpendicular to the rotation axis of the rotation support 112 between the center axis c (FIG. 15) of the cylindrical body 2 held by the holding device 100 and the center axis of the probe 261. The vertical line passing through the central axis c of the cylindrical body 2 by moving the cylindrical body 2 in the X direction parallel to the orthogonal plane by the distance of) is the central axis of the probe 261 (therefore, the rotational axis of the rotary support 112). ) Next, the distance between the center axis of the end 4c of the heat transfer tube 4 to be welded on the reference drawing and the center axis of the cylindrical body 2 (tube sheet 3), and the center axis of the probe 261 and the holding device The end of the heat transfer tube 4 to be welded on the reference drawing by moving the cylindrical body in the Y direction (vertical direction) by the distance from the central axis c of the cylindrical body 2 held by 100 The central axis of 4c is made to coincide with the central axis of the probe 261. At this time, if the actual position 4c ′ of the end of the heat transfer tube 4 to be welded in the end plate 3 of the cylindrical body 2 held by the holding device 100 is shifted from the position 4c on the reference drawing, the cylindrical shape The positional relationship among the central axis c of the body 2, the end 4c of the heat transfer tube to be welded on the reference drawing, and the end 4c 'of the actual heat transfer tube 4 to be welded is as shown in FIG. If displacement x, y is obtained by inserting the probe 261 into the heat transfer tube 4 from this state as described above, the inclination θ of the cylindrical body held by the holding device 100 with respect to the central axis c of the cylindrical body Thus, the positions of the other heat transfer tubes from the rotation axis of the rotary support 112 can be known, and therefore, the other heat transfer tubes are sequentially aligned with the center axis of the probe 261 (the rotation axis of the rotary support 112). Thus, welding can be performed sequentially.

The position of another heat transfer tube from the rotation axis of the rotary support 112 can be determined as follows.
The center axis of the probe 261 before being inserted into the heat transfer tube 4 is made to coincide with the rotation axis of the rotary support 112, and the end 4a of the heat transfer tube 4 to be welded is shown on the reference drawing of the tube plate 3. It is assumed that the tube plate 3 is inserted into a tube hole on a vertical line passing through the center axis of the tube sheet 3 (and hence the center axis of the cylindrical body 2).
[Welding operation by torch unit 210]

In order to perform the welding operation by the torch unit 210, first, the welding portion base 204 is positioned so that the torch unit 210 is located at a position facing the tube sheet 3.
Next, the front / rear reference position setting sliding body 214 is advanced by the horizontal cylinder 213 and stopped at a position where the stopper 215 contacts the tube plate 3 of the cylindrical body 2, the vertical air cylinder 216 is operated, and the rod protrudes upward. Let Next, the lower support 218 is advanced by the horizontal air cylinder 219 and stopped and held at a position (reference position) where the stopper 217 contacts the rod of the vertical air cylinder 216. Thereafter, the vertical air cylinder 216 is operated to house the rod, and the front / rear reference position setting sliding body 214 is moved backward by the horizontal air cylinder 213.
Further, the height of the torch 230 is adjusted by the vertical air cylinder 221 according to the diameter of the cylindrical body 2 to be welded. The horizontal air cylinder 224 is operated by using or not using the filler to adjust the front-rear position of the torch 230.
If necessary, the angle, height, distance, and the like of the torch 230 with respect to the welding location are finely adjusted by the front / rear adjustment unit 225, the vertical adjustment unit 226, the horizontal support member 228, and the vertical support member 229 as described above.
Thereafter, arc welding by the torch 230 is performed while rotating the holding device 100 around the central axis of the heat transfer tube 4 to be welded, which is aligned with the rotational axis of the rotary support 112 as described above.

  The present invention is not limited to welding of heat transfer tubes of a heat exchanger, and can be applied to an apparatus for welding a plurality of members having the same shape, such as welding bolts to a hub of a vehicle.

Heat transfer tube end welding device 1 (“Welding device of workpiece to be welded having a large number of welding points” in claims); Heat exchanger tubular body 2; Tube plate 3 (workpiece); Heat transfer tube 4; End 4a; Holding device 100 (workpiece holding device); Base 110; Main body 111; Through opening 111a; Gear teeth 112a; Rotating support 112; Support base 113; Guide rail 114; 1 linear displacement member 115 (which constitutes “a workpiece holding means” together with the second linear displacement member 119 and the clamp members 121a and 121b); servo motor 117; guide rail 118; second linear displacement member 119; handle 120; Body 112; clamp members 121a and 121b; servo motor 122; motor base 123; servo motor 124; bevel gear box 125; Base 201; Welding part base 204; Torch unit 210; Torch support part 210A; Welding base frame 211; Front / rear reference position setting slide 214; Lower support 218; Intermediate support 220; Upper support 222; Front / rear adjustment unit 225; L-shaped bracket 227; vertical support member 229; horizontal support member 228; arcuate hole 228a; vertical adjustment unit 226; arcuate hole 229a; torch 230; vertical air cylinder 221; vertical air cylinder 216; stopper 215; Horizontal air cylinder 219; Stopper 217; Probe unit 250; Probe base 251; Horizontal guide rail 252; Horizontal guide rail 252; Front and rear sliding body 253; Horizontal air cylinder 254; Horizontal guide rail 256; Stoppers 255a and 255 ; Horizontal sliding body 257; stoppers 258a, the stopper 258b; vertical guide rails 259; vertical slide 260; tip portion 260a; sensor 262; Sensors 263

Claims (5)

In a work piece having a surface having a number of points to be welded, welding to the point is performed along a circle with a constant radius centering on each axis passing through each point to be welded and extending in a direction perpendicular to the surface. Performing a welding device,
The work piece is held in a predetermined position in the welding apparatus so as to be rotatable around a rotation axis extending perpendicularly to the surface, and an arbitrary place among the places where the work piece is welded is provided. A workpiece holding device that is displaceable in parallel to the surface so that the axis passing therethrough coincides with the rotation axis;
A weld with a torch that can be set at a position adjacent to the axis of rotation;
Have
The welding object holding device is
A rotating support made rotatable about the rotation axis;
Provided on the rotary support, holds the workpiece, and is displaceable in parallel to a plane perpendicular to the rotational axis, so that the axis passing through the welding point can be aligned with the rotational axis. Means for holding the workpiece,
By being set at a reference position in the welding apparatus and displaceable in parallel to a plane perpendicular to the rotation axis of the rotary support, by displacing from the reference position to the position of the axis passing through the welding position A probe for determining a distance from the reference position to the axis of the welding point;
Have
The workpiece holding means is configured to change the axis passing through the welding point to the rotation axis based on the position of the axis passing through the welding point determined from the determined distance with respect to the rotation axis of the rotary support. The work piece is moved to align, and
A constant radius around the axis passing through the arbitrary position by the torch by rotating the workpiece around the rotational axis in a state where the axis passing through the arbitrary position coincides with the rotational axis. The welding apparatus of the to-be-welded object which has many welding locations adapted to perform welding along the circle | round | yen . The workpiece holding means includes a first linear displacement member attached to the rotary support and capable of being displaced in one direction orthogonal to the rotation axis within a plane orthogonal to the rotation axis; A second linear displacement member attached to the first linear displacement member and displaceable in a direction orthogonal to the displacement direction of the first linear displacement member within the plane; and the welded workpiece attached to the second linear displacement member The welding apparatus for an object to be welded having a large number of welding points according to claim 1 , further comprising a clamp member that grips the object. The workpiece is a tube sheet of a heat exchanger having end portions of heat transfer tubes inserted into a number of tube holes provided on the surface,
The work-piece holding means is adapted to hold a cylindrical body having the tube sheet at its end,
The probe has a tapered tip portion extending toward the face of the tube plate, and the tip portion is inserted into the end of the heat transfer tube to be welded so that the center axis of the probe is welded. It displaced so as to coincide with the central axis of the heat pipe, according to claim 1 or 2 which is adapted to determine the distance to the central axis of the heat exchanger tube in contact solution from the reference position by displacing to match Welding apparatus for workpieces having a large number of welding points. The workpiece holding means calculates the center axis of the other pipe based on the position of the center axis of the other pipe with respect to the rotation axis of the rotary support calculated based on the determined distance. 4. A welding apparatus for welding objects having a large number of welding points according to claim 1 , wherein the welding axis is sequentially aligned with the rotation axis of the welding object. A method of using a welding apparatus for an object to be welded having a large number of welding points according to claim 3 ,
Aligning the central axis of the probe at the reference position with the rotational axis of the rotating support;
It is assumed that the end of the heat transfer tube to be welded is inserted into one tube hole on a vertical line passing through the central axis of the tube sheet on the tube sheet reference drawing,
The cylindrical body is moved by a distance in the horizontal direction in a plane perpendicular to the rotational axis of the rotary support between the central axis of the cylindrical body held by the workpiece holding means and the central axis of the probe. Move horizontally parallel to the same plane so that the vertical line passing through the central axis of the cylindrical body passes through the central axis of the probe,
By moving the cylindrical body vertically by a distance perpendicular to the center axis of the end of the heat transfer tube to be welded on the reference drawing and the center axis of the probe, the heat transfer tube to be welded on the reference drawing Make sure that the center axis of the end matches the center axis of the probe,
The deviation of the actual position of the end of the heat transfer tube to be welded in the end plate of the cylindrical body held by the workpiece holding means at this time is specified from the position on the reference drawing, and the workpiece is based on this deviation. Identify the inclination of the cylindrical body held by the holding means relative to the central axis of the cylindrical body;
The welding method which specified the position of the edge part of the other heat exchanger tube with respect to the rotating shaft line of a rotation support body by this, and welded the edge part of this other heat exchanger tube sequentially.

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