JP6579306B2 - Welding equipment - Google Patents

Description

  Embodiments according to the present invention relate to a welding apparatus.

  An annular gear surrounding a cylindrical workpiece (generally piping) is provided, the welding head is made to follow the joint of the workpiece, and the welding head is turned in the circumferential direction of the workpiece to be welded. There is known a welding apparatus for joining the two.

  There is also known a gear that includes a first main gear body, a first auxiliary gear body, and a coil spring and does not cause backlash.

JP 2013-184176 A JP-A-7-133862

  For example, when the conventional welding apparatus is applied to a medium or large diameter pipe having a diameter exceeding 250 mm, at least a pipe for an annular torch for moving the welding head and an annular wire gear for feeding a wire to the welding head are provided. It is necessary to make the diameter larger than the outer diameter.

  However, in the conventional welding apparatus, if the diameter of the annular torch gear or wire gear is simply increased, it becomes difficult to ensure machining accuracy, or the weight of the torch gear or wire gear increases. If it is too much, it becomes difficult to attach to the work piece, and the convenience of handling is significantly impaired.

  Further, in order to increase the processing accuracy by the welding apparatus, it is necessary to increase the positioning accuracy of the welding torch, and consequently, it is necessary to reduce the backlash of the gear.

  Therefore, the present invention has an object to provide a welding apparatus that can secure welding accuracy with exceptionally high processing accuracy in medium-sized and large-diameter pipes and has good handling convenience for small-diameter pipes. And

In order to solve the above problems, a welding apparatus according to an embodiment of the present invention includes an annular base portion that is fixed to the outer periphery of a cylindrical workpiece, and a plurality of second bases that are alternately meshed with each other along the base portion. An annular gear train including one gear and a plurality of second gears; an arcuate turning gear having internal teeth meshed with the first gear of the annular gear row; and a circumferential direction of the base portion fixed to the turning gear And a turntable that supports the welding head, and an electric motor that generates a driving force transmitted to the first gear of the annular gear train. The second gear has a smaller diameter than the first gear, and a line connecting the rotation centers of the plurality of first gears draws a circle concentric with the base, and each of the plurality of second gears A line connecting the rotation centers draws a circle concentric with the base.

The front view which shows the welding apparatus which concerns on embodiment of this invention. The side view which shows the welding apparatus which concerns on embodiment of this invention. The rear view which shows the welding apparatus which concerns on embodiment of this invention. The front view which shows the drive mechanism of the welding apparatus which concerns on embodiment of this invention. Sectional drawing which shows the drive mechanism of the welding apparatus which concerns on embodiment of this invention. The conceptual diagram which shows the relationship between the swivel of the welding apparatus which concerns on embodiment of this invention, and a drive mechanism. The conceptual diagram which shows the relationship between the swivel of the welding apparatus which concerns on embodiment of this invention, and a drive mechanism. The conceptual diagram which shows the relationship between the swivel of the welding apparatus which concerns on embodiment of this invention, and a drive mechanism. Sectional drawing which shows the differential gear mechanism of the welding apparatus which concerns on embodiment of this invention. Sectional drawing which shows the differential gear mechanism of the welding apparatus which concerns on embodiment of this invention. The plane sectional view showing the welding head of the welding device concerning this embodiment. The figure which shows a part of wire feed mechanism of the welding apparatus which concerns on this embodiment. The figure which shows a part of wire feed mechanism of the welding apparatus which concerns on this embodiment. The longitudinal cross-sectional view which shows the purge gas supply path | route of the welding apparatus which concerns on this embodiment. The cross-sectional view which shows the purge gas supply path | route of the welding apparatus which concerns on this embodiment. Sectional drawing explaining operation | movement of the purge gas supply path | route of the welding apparatus which concerns on this embodiment. Sectional drawing explaining operation | movement of the purge gas supply path | route of the welding apparatus which concerns on this embodiment. The cross-sectional view which shows the power supply system of the welding apparatus which concerns on this embodiment. The longitudinal cross-sectional view which shows the power supply system of the welding apparatus which concerns on this embodiment.

  An embodiment of a welding apparatus according to the present invention will be described with reference to FIGS.

  FIG. 1 is a front view showing a welding apparatus according to an embodiment of the present invention.

  FIG. 2 is a side view showing the welding apparatus according to the embodiment of the present invention.

  FIG. 3 is a rear view showing the welding apparatus according to the embodiment of the present invention.

  The welding apparatus 1 according to this embodiment shown in FIGS. 1 to 3 welds and integrates a pair of cylindrical workpieces 200a and 200b. The pair of cylindrical workpieces 200a and 200b are, for example, pipes, and have butt joints at the ends. The welding apparatus 1 welds this joint to integrate the pair of workpieces 200a and 200b. For ease of explanation, the welding apparatus 1 is fixed to the workpiece 200a side and welds the joint between the workpieces 200a and 200b, but is fixed to the workpiece 200b side and fixed. A joint between the weldments 200a and 200b can also be welded.

  The welding apparatus 1 generates an annular base 2 fixed to the outer periphery of the workpiece 200a, a swivel 5 that is movable in the circumferential direction of the base 2 and supports the welding head 3, and generates a driving force for the swivel 5 And a motor housing 7 that supports the plurality of electric motors 6.

  The base 2 is fixed to the outer periphery of the workpiece 200a and supports the entire welding apparatus 1. The inner diameter dimension of the base portion 2 is larger than the outer diameter dimension of the workpiece 200a, and the workpiece 200a is disposed inside the base portion 2 and in a circular space.

  The base 2 includes a plurality of (for example, five) clamps 8 that are arranged on the inner peripheral edge of each of the front and back surfaces and that can freely protrude and retract in the radial direction of the base 2. The plurality of clamps 8 are arranged at substantially equal intervals in the circumferential direction of the base 2. The clamp 8 moves to the workpiece 200 a side with respect to the inner diameter of the base portion 2 and contacts the workpiece 200 a having a smaller diameter than the inner diameter of the base portion 2 to support the entire welding apparatus 1.

  Further, the base 2 includes a power supply through hole 11 through which a power supply conductor 9 for supplying power to the welding head 3 is inserted, and a ground electrode piece (not shown) for grounding the power supply conductor 9 to the workpiece 200a. It is equipped with.

  The base portion 2 is divided into a plurality of portions, for example, two semicircular arc portions 2a and 2b in the circumferential direction. The welding device 1 can be arranged on the outer periphery of the workpiece 200a by the divided structure of the base 2. The welding apparatus 1 can be easily attached to and detached from the workpiece 200a by dividing the base 2.

  In addition, the base portion 2 includes a fixing mechanism 12 that connects and fixes the semicircular arc portions 2a and 2b. The fixing mechanism 12 is disposed on the front surface and the back surface of the base portion 2 and in the vicinity of the split surfaces of the semicircular arc portions 2a and 2b.

  The swivel 5 includes a torch holder 13 that supports the welding head 3. The swivel 5 swivels around the workpiece 200a and the workpiece 200b along the outer peripheral edge of the base 2 and moves the welding head 3. The torch holder 13 is extremely small compared to the circumferential length of the base 2 and contributes to weight reduction of the welding apparatus 1, although depending on the diameters of the workpieces 200 a and 200 b and the dimensions of the welding head 3.

  The plurality of electric motors 6 generate, for example, a driving electric motor 15 that generates a driving force for the swivel base 5 and a driving force that moves the welding torch 19 in the longitudinal direction of the workpieces 200a and 200b (the direction in which the pipe extends). A torch longitudinal motor 16, a torch perspective motor 17 that generates a driving force that moves the welding torch 19 closer to or away from the workpieces 200 a and 200 b, and a wire feeding and feeding motor 18 that feeds a wire to the welding torch 19. , Including. In addition, the movement to the to-be-welded object 200a, 200b of the welding torch 19 to the longitudinal direction (pipe extension direction) is called the longitudinal movement movement of the welding torch 19.

  The motor housing 7 is disposed at any location on the back surface of the base 2.

  The welding apparatus 1 includes a reel (not shown) that is supported by the swivel 5 together with the welding head 3 and winds the wire before feeding, and a wire guide (not shown) that guides the wire to the joint of the workpieces 200a and 200b. (Omitted).

  The welding head 3 joins the joints of the workpieces 200a and 200b by arc welding. Specifically, welding torches suitable for various types of arc welding such as TIG welding (TIGsten Inert Gas welding), MAG welding (MAG Active: Metal Active Gas welding), and MIG welding (MIG Welding: Metal Inert Gas welding). 19 is appropriately selected and attached to the welding head 3.

  Next, the drive mechanism of the welding apparatus 1 will be described in detail.

  FIG. 4 is a front view showing a drive mechanism of the welding apparatus according to the embodiment of the present invention.

  FIG. 5 is a cross-sectional view showing the drive mechanism of the welding apparatus according to the embodiment of the present invention, taken along line VV in FIG.

  As shown in FIG. 4 and FIG. 5, the welding apparatus 1 according to the present embodiment alternately has an annular base portion 2 fixed to the outer periphery of a cylindrical workpiece 200 a and an annular arrangement along the base portion 2. A gear train mechanism 25 having a plurality of annular gear trains 23 including a plurality of meshed first gears 21 and a plurality of second gears 22, and an internal tooth 27 meshed with the first gear 21 of any of the annular gear trains 23. An arcuate swivel gear 28, a swivel base 5 fixed to the swivel gear 28 and movable in the circumferential direction of the base 2 and supporting the welding head 3, and a swivel base 5 reciprocally held by the swivel base 5 An arc-shaped reciprocating gear 33 having inner teeth 31 and outer teeth 32 meshed with the first gear 21 of the annular gear train 23, and meshed with the outer teeth 32 of the reciprocating gear 33 supported by the swivel 5. To transmit power to the welding head 3 A transmission gear 35, and a plurality of electric motor 6 for the driving force transmitted to the first gear 21 of each annular gear train 23 is generated individually and.

  In addition, the welding apparatus 1 includes a differential gear mechanism 36 interposed between each of the plurality of electric motors 6 and each of the first gears 21 of the plurality of annular gear trains 23.

  The base 2 includes an annular front face plate 37 disposed on the front surface, and an annular rear face plate 38 disposed on the rear face side. The front face plate 37 and the back face plate 38 have substantially the same inner and outer diameter shapes, and face each other with a gap in which the annular gear train 23 is disposed. The front face plate 37 and the back face plate 38 have an annular guide groove 39 for guiding the swivel base 5 on the inner surface (surfaces facing each other) side.

  The gear train mechanism 25 transmits the power generated by the plurality of electric motors 6 to the swivel gear 28 or the reciprocating gear 33 through the respective annular gear trains 23 to move the swivel 5 and to weld torches 19 to the workpieces 200a and 200b. , The longitudinal movement of the welding torch 19 and the feeding of the wire. Therefore, there are a plurality of annular gear trains 23. Specifically, the annular gear train 23 transmits the power from the swing motor 15 to the swing gear 28, and the torch transmits the power from the torch longitudinal motion motor 16 to the torch longitudinal motion reciprocating gear 56. Power is transmitted to the longitudinal gear train 46, the torch perspective gear train 47 that transmits power from the torch perspective motor 17 to the torch perspective reciprocating gear 57, and the wire feeding power supply motor 18 to the wire feeding reciprocating gear 58. And a gear train for wire 48.

  Each of the annular gear train 23, that is, the turning gear train 45, the torch longitudinal gear train 46, the torch distance gear train 47, and the wire gear train 48, includes a plurality of first gears 21 and a plurality of first gears 21 that are alternately meshed. The driving force is transmitted by the two gears 22. The first gear 21 and the second gear 22 of each annular gear train 23 are arranged on the same rotational axis and are sandwiched between the front face plate 37 and the back face plate 38 of the base 2. The turning gear train 45 is arranged closest to the rear face plate 38, and then approaches the front face plate 37 in the order of the torch longitudinal movement gear train 46 and the torch distance gear train 47, and the wire gear train 48 is located closest to the front face plate 37. Is arranged.

  In each annular gear train 23, the first gears 21 are arranged at suitable intervals so that the swivel 5 can be driven over the entire circumference of the base 2. The second gear 22 has a smaller diameter than the first gear 21. The second gear 22 is disposed between the adjacent first gears 21 and transmits power. The second gear 22 may be between all the first gears 21, or may be thinned out at one place on the circumference as in the present embodiment.

A line connecting the respective rotational centers of the large-diameter first gear 21 is arranged to draw the annular base portion 2 concentrically. Each line connecting the center of rotation of the plurality of small-diameter second gear 22 is disposed to draw an annular base portion 2 concentrically, and each of the rotation center line, a pair of adjacent first gear 21 It is arranged on a line segment connecting the rotation center lines.

  The second gear 22 has a dimension that makes the backlash between the first gear 21 and the second gear 22 substantially zero every other one. The second gear 22 has a backlash greater than zero between the first gear 21 and the second gear 22 every other one. In other words, the second gear 22 is larger than zero between the first gear 21 and the second gear 22 having a dimension that makes the backlash between the first gear 21 and the second gear 22 substantially zero. Those having backlash are alternately arranged. On the other hand, all the first gears 21 have substantially the same dimensions.

  The annular gear train 23 may reverse the dimensional relationship between the second gear 22 and the first gear 21. That is, the first gear 21 has a dimension that makes the backlash between the first gear 21 and the second gear 22 substantially zero every other one, and the first gear 21 and the second gear 22 every other one. A backlash greater than zero may be provided between the two gears 22. In other words, the first gear 21 is larger than zero between the first gear 21 and the second gear 22 having a dimension that makes the backlash between the first gear 21 and the second gear 22 substantially zero. Those having backlash may be alternately arranged. In this case, all the second gears 22 have substantially the same dimensions.

  That is, any one of the first gear 21 and the second gear 22 has such a dimension that the backlash between the first gear 21 and the second gear 22 is substantially zero every other one. The first gear 21 and the second gear 22 have a backlash greater than zero. In other words, one of the first gear 21 and the second gear 22 has a dimension that makes the backlash between the first gear 21 and the second gear 22 substantially zero, and the first gear 21 and the second gear 22. Those having a backlash greater than zero are alternately arranged with the gear 22. The other one of the first gear 21 and the second gear 22 has substantially the same dimensions.

  The first gear 21 of the annular gear train 23 and the internal teeth 27 of the swivel gear 28 have a dimensional relationship that makes backlash substantially zero. The first gear 21 of the annular gear train 23 and the inner teeth 31 of the reciprocating gear 33 are also in a dimensional relationship that makes backlash substantially zero. However, when the first gear 21 and the second gear 22 have substantially zero backlash and those having a backlash greater than zero on the first gear 21 side, the inner teeth 27 and the inner gear 27 It is preferable that the size of the tooth 31 is adjusted according to the first gear 21 having the larger transfer amount, and at least one of the first gears 21 having the larger transfer amount is always meshed.

  The swivel base 5 includes a roller portion 59 that is fitted into the guide groove 39 of the base portion 2. The roller portion 59 supports the swivel 5 against the radially outer force generated in the swivel gear 28 by the rotation of the first gear 21.

  In addition, the swivel 5 has a torch installation surface 61 that extends in the tangential direction of the base 2 and spreads.

  The power transmission gear 35 includes a torch longitudinal power transmission gear 66 meshed with the external teeth 32 of the torch longitudinal reciprocating gear 56 and a torch distance power transmission gear meshed with the external teeth 32 of the torch distance reciprocating gear 57. 67, and a wire feeding power transmission gear 68 that meshes with the external teeth 32 of the wire feeding reciprocating gear 58.

  The plurality of electric motors 6 are provided for each annular gear train 23. That is, the turning electric motor 15 is connected to at least the turning gear train 45, the torch longitudinal motor 16 is connected to at least the torch longitudinal gear train 46, the torch perspective motor 17 is connected to at least the torch perspective gear train 47, The wire feeding / feeding motive 18 is connected to at least the wire gear train 48.

  The differential gear mechanism 36 includes a torch longitudinal movement differential gear mechanism 76 that transmits the driving force of the turning electric motor 15 and the torch longitudinal movement motor 16 to the torch longitudinal movement gear train 46, and the turning electric motor 15 and the torch perspective electric motor 17. A differential gear mechanism 77 for transmitting and receiving the driving force to the gear train 47 for the distance to the torch, and a differential gear mechanism for the wire for transmitting the driving force of the turning motor 15 and the wire feeding / feeding motor 18 to the gear train 48 for the wire. 78.

  FIG. 6 is a conceptual diagram showing the relationship between the swivel and the drive mechanism of the welding apparatus according to the embodiment of the present invention.

  As shown in FIG. 6, the turning gear 28 of the welding apparatus 1 according to the present embodiment is meshed with the outer periphery of the first gear 21 of the annular gear train 23, specifically, the turning gear train 45. The swivel gear 28 moves in the circumferential direction of the base portion 2 by the rotation of the first gear 21 of the swivel gear train 45 and generates the propulsive force of the swivel base 5. The turning gear 28 only needs to mesh with at least one first gear 21.

  7 and 8 are conceptual diagrams showing the relationship between the swivel and the drive mechanism of the welding apparatus according to the embodiment of the present invention.

  As shown in FIGS. 7 and 8, the reciprocating gear 56 for torch longitudinal movement of the welding apparatus 1 according to the present embodiment is restricted in the movement range by the swivel 5, while the first of the torch longitudinal movement gear train 46. The inner teeth 31 meshed with the gear 21 move in the circumferential direction of the base 2 and simultaneously move with respect to the swivel base 5.

  The torch longitudinal movement reciprocating gear 56 has a guide hole 79 extending along an arc shape. The reciprocating gear 56 for longitudinal movement of the torch is supported on the turntable 5 by a guide rod 81 disposed in the guide hole 79. The guide rod 81 supports the reciprocating gear 56 for torch longitudinal movement against the radially outward force generated in the reciprocating gear 56 for torch longitudinal movement that moves as the first gear 21 rotates.

  The movement of the reciprocating gear 56 for torch longitudinal movement moves the outer teeth 32 together with the inner teeth 31 and rotates the torch longitudinal power transmission gear 66 meshed with the outer teeth 32.

  The torch longitudinal movement power transmission gear 66 is rotated in two directions according to the forward and backward movements of the torch longitudinal movement reciprocating gear 56, that is, the reciprocating gear 33.

  Note that the torch distance reciprocating gear 57 meshed with the first gear 21 of the torch distance gear train 47 and the wire feeding reciprocating gear 58 meshed with the first gear 21 of the wire gear train 48 include a torch. Since the same structure as the reciprocating gear 56 for torch longitudinal movement meshed with the first gear 21 of the longitudinal gear train 46 is employed, the description thereof is omitted. Similarly, since the torch longitudinal power transmission gear 67 and the wire feeding power transmission gear 68 have the same structure as the torch longitudinal movement power transmission gear 66, the description thereof will be omitted.

  The welding device 1 moves the swivel base 5 and moves the welding torch 19 in a longitudinal manner by coordinating the rotation of the turning gear train 45, the torch longitudinal motion gear train 46, the torch perspective gear train 47 and the wire gear train 48. Movement, distance movement of the welding torch 19 and wire feeding are performed.

  Specifically, when the first gear 21 of the turning gear train 45, the torch longitudinal motion gear train 46, the torch distance gear train 47, and the wire gear train 48 rotates in the same direction at the same speed, the swivel 5 moves. On the other hand, the longitudinal movement of the welding torch 19, the distance movement of the welding torch 19 and the feeding of the wire are stopped. This is because the first gear 21 of the turning gear train 45, the torch longitudinal gear train 46, the torch distance gear train 47 and the wire gear train 48 rotates in the same direction at the same speed, thereby reciprocating with the turning gear 28. This is because the movement with the moving gear 33 is synchronized, and consequently the power transmission gear 35 stops relative to the swivel base 5.

  Here, attention is paid to the turning gear train 45 and the torch longitudinal motion gear train 46.

  When the turning gear train 45 and the torch longitudinal movement gear train 46 rotate at relatively different speeds, the torch longitudinal movement reciprocating gear 56 moves with respect to the turning gear 28 and consequently the turntable 5 due to the difference in rotational speed between them. As a result, the torch longitudinal movement power transmission gear 66 rotates to move the welding head 3 in the longitudinal movement. Whether or not the welding torch 19 moves vertically depends on whether or not there is a relative rotational speed difference between the turning gear train 45 and the torch longitudinal moving gear train 46. It does not depend on whether or not you are moving. The combination of the turning gear train 45 and the torch perspective gear train 47 and the combination of the turning gear train 45 and the wire gear train 48 operate in the same manner.

  FIG. 9 is a cross-sectional view showing the differential gear mechanism of the welding apparatus according to the embodiment of the present invention.

  As shown in FIG. 9, the differential gear mechanism 76 for torch longitudinal movement of the welding apparatus 1 according to the present embodiment includes a differential case 82 as a casing, a ring gear 83 as an input gear that is integrally rotated with the differential case 82, and a differential. A pinion shaft 85 housed in the case 82 and extending in a direction orthogonal to the rotation center line of the ring gear 83, a pair of pinion gears 86 rotatably supported by the pinion shaft 85, and the ring gear 83 rotating in mesh with the pinion gear 86. A pair of side gears 87 and 88 rotating on the center line, a drive shaft 89 connected to the side gear 87, and a drive gear 91 rotating integrally with the side gear 88 are provided.

  The torch longitudinal movement differential gear mechanism 76 transmits the driving force of the torch longitudinal movement motor 16 input to the ring gear 83 from the drive gear 91 to the torch longitudinal movement gear train 46, while the turning electric motor input to the drive shaft 89. 15 driving force is transmitted from the drive gear 91 to the torch longitudinal movement gear train 46.

  Each of the pair of pinion gears 86 and the pair of side gears 87 and 88 is a bevel gear, each of the pair of pinion gears 86 rotates on the same rotation center line, and each of the pair of side gears 87 and 88 also rotates on the same rotation center line. To do. The center of rotation is orthogonal between the gear pairs. Note that the differential gear mechanism 76 for torch longitudinal movement may be a differential device that combines gears and screws other than bevel gears. Each of the differential gear mechanisms 36 including the torch longitudinal movement differential gear mechanism 76 is the same.

  The number of effective teeth of the inner teeth 31 of the reciprocating gear 56 for torch longitudinal movement is equal to or less than the number of teeth of the ring gear 83 of the differential gear mechanism 76 for torch longitudinal movement.

  In addition, the welding apparatus 1 includes a rotation sensor 92 that detects the rotation of the differential case 82 of the differential gear mechanism 76 for torch longitudinal movement. Although the rotation sensor 92 may be capable of measuring the rotation angle of the differential case 82, the welding device 1 according to the present embodiment has the number of effective teeth of the inner teeth 31 of the reciprocating gear 56 for torch longitudinal movement as follows. By making the number of teeth of the ring gear 83 of the differential gear mechanism for torch longitudinal movement 76 or less, the rotational phase of the differential case 82 at one end position of the reciprocating gear 56 for torch longitudinal movement is detected by a microswitch, The rotation amount of the first gear 21 of the torch longitudinal movement gear train 46 is determined from the rotation amount of the torch longitudinal movement motor 16 with reference to this detection position, and as a result, the rotation amount of the torch longitudinal movement power transmission gear 66 can be calculated.

  First, the relationship between the turning electric motor 15 and the turning gear train 45 will be described.

  The driving force generated by the turning electric motor 15 is transmitted to the shaft 105 through the gear 103 meshed with the gear 102 from the gear 102 that is rotated and integrated with the output shaft 101. The driving force transmitted to the shaft 105 is transmitted to the first gear 21 of the turning gear train 45 through the gear 107 meshed with the gear 106 that is integrally rotated with the shaft 105.

  Next, the relationship between the turning electric motor 15 and the torch longitudinal movement gear train 46 will be described. Assuming that the torch longitudinally moving motor 16 is stopped, the stopped portion is depicted by a broken line in FIG.

  The driving force transmitted to the shaft 105 is transmitted from the gear 111 meshed with the gear 106 and the gear 109 meshed with the gear 108 to the differential gear mechanism 76 for torch longitudinal movement from the gear 111 rotated and integrated with the drive shaft 89. The

  The differential gear mechanism 76 for torch longitudinal movement rotates the differential case 82 via a ring gear 83 that meshes with the output shaft 112 of the torch longitudinal motion motor 16 and a gear 113 that is integrally rotated with the output shaft 112 of the torch longitudinal motion motor 16. Is blocked. The differential gear mechanism 76 for torch longitudinal movement that is prevented from rotating the differential case 82 rotates the side gear 87 by the driving force of the drive shaft 89, and the driving force to the side gear 88 through the rotation of the pair of pinion gears 86 meshed with the side gear 87. To communicate. The driving force transmitted to the side gear 88 is transmitted to the first gear 21 of the torch longitudinal movement gear train 46 through the gear 115 meshed with the drive gear 91.

  Through such a power transmission path, the driving force of the turning electric motor 15 is distributed to the turning gear train 45 and the torch longitudinal movement gear train 46. Then, by setting the gear ratio in each path to be the same, only the turning electric motor 15 is driven, and the turning gear 28 and the torch longitudinal movement reciprocating gear 56 are moved synchronously at the same angular velocity, and consequently the torch. Without rotating the longitudinal power transmission gear 66, the swivel 5 is moved while preventing the welding torch 19 from moving in the near and far directions.

  On the other hand, the relationship between the torch longitudinal motion motor 16 and the torch longitudinal motion gear train 46 will be described.

  FIG. 10 is a cross-sectional view showing the differential gear mechanism of the welding apparatus according to the embodiment of the present invention.

  Assuming that the turning electric motor 15 is stopped, the stop portion is depicted by a broken line in FIG.

  As shown in FIG. 10, the driving force generated by the torch longitudinal motion motor 16 is differentially transmitted from the gear 113 that is integrally rotated with the output shaft 112 to the ring gear 83 of the differential gear mechanism 76 for torch longitudinal motion that meshes with the gear 113. It is transmitted to the case 82. The differential case 82 integrally rotates a pair of pinion gears 86 whose rotation center lines are orthogonal to each other together with the pinion shaft 85.

  At this time, since the turning electric motor 15 is stopped, the torch longitudinal movement differential gear mechanism 76 is connected to the drive shaft 89 via the output shaft 101, the gears 102 and 103, the shaft 105, and the gears 106, 108, 109, and 111. Rotation is prevented. In the torch longitudinal differential gear mechanism 76 that prevents the rotation of the drive shaft 89, the rotation of the side gear 87 is also blocked, while the pair of pinion gears 86 are rotated by the non-rotating side gear 87 and meshed with the pair of pinion gears 86. The driving force is transmitted to the side gear 88. The driving force transmitted to the side gear 88 is transmitted to the first gear 21 of the torch longitudinal movement gear train 46 through the gear 115 meshed with the drive gear 91.

  Next, the relationship between the torch longitudinal motor 16 and the turning gear train 45 will be described.

  As described above, the torch longitudinal movement differential gear mechanism 76 is driven via the output shaft 101, the gears 102 and 103, the shaft 105, and the gears 106, 108, 109 and 111 because the turning electric motor 15 is stopped. The rotation of the shaft 89 is prevented. Therefore, the driving force of the torch longitudinal motor 16 is not transmitted to the turning gear train 45.

  The driving force of the torch longitudinal motion motor 16 is transmitted to the torch longitudinal motion gear train 46 through such a power transmission path.

  The welding apparatus 1 rotates the turning electric motor 15 and the torch longitudinal movement motor 16 simultaneously with appropriate outputs, so that the first gear 21 of the turning gear train 45 and the first gear 21 of the torch longitudinal movement gear train 46 are rotated. An angular velocity difference is generated between the rotary table 5 and the vertical movement of the welding torch 19 and simultaneously the movement of the swivel 5, that is, the turning of the welding torch 19.

  The torch perspective differential gear mechanism 77 and the wire differential gear mechanism 78 have the same structure as that of the torch longitudinal movement differential gear mechanism 76, and thus description thereof is omitted. That is, the welding apparatus 1 simultaneously rotates the turning electric motor 15 and the torch perspective electric motor 17 with appropriate outputs, thereby causing the first gear 21 of the turning gear train 45 and the first gear 21 of the torch perspective gear train 47 to An angular velocity difference is generated between the two, and the movement of the swivel 5 at the same time as the welding torch 19 is moved, that is, the turning of the welding torch 19 is made compatible. Further, the welding apparatus 1 rotates the turning electric motor 15 and the wire feeding / feeding power supply 18 at the same time with appropriate outputs, so that the first gear 21 of the turning gear train 45 and the first gear 21 of the wire gear train 48 are Each speed difference is generated between the two, so that the movement of the swivel 5 at the same time as the feeding of the wire, that is, the swiveling of the welding head 3 and consequently the welding torch 19 is made compatible.

  Next, the welding head of the welding apparatus according to the present embodiment will be described.

  FIG. 11 is a plan sectional view showing a welding head of the welding apparatus according to the present embodiment.

  12 and 13 are views showing a part of the wire feeding mechanism of the welding apparatus according to the present embodiment.

  As shown in FIGS. 11 to 13, the welding head 3 of the welding apparatus 1 according to the present embodiment includes a torch longitudinal movement mechanism 126 that moves the welding torch 19 in the longitudinal direction, and a torch perspective movement that moves the welding torch 19 in the distance. A mechanism 127 and a wire feeding mechanism 128 that supplies a wire to the welding torch 19 are provided.

  The torch longitudinal movement mechanism 126 is actuated by the driving force transmitted from the torch longitudinal movement power transmission gear 66 of the power transmission gear 35 to move the welding torch 19 in the longitudinal direction.

  The torch distance moving mechanism 127 is operated by the driving force transmitted from the torch distance power transmission gear 67 in the power transmission gear 35 to move the welding torch 19 in the distance direction.

  The wire feeding mechanism 128 is operated by a driving force transmitted from the wire feeding power transmission gear 68 of the power transmission gear 35, and supplies the wire to the welding torch 19.

  By the way, since the wire feeding reciprocating gear 58 for transmitting power to the wire feeding power transmission gear 68 reciprocates with respect to the swivel 5 and eventually the welding head 3, the wire feeding power transmission gear 68 is Forward rotation and reverse rotation are periodically repeated. In other words, in order to supply the wire, the reciprocating motion of the wire feeding reciprocating gear 58 is the reciprocating motion of the wire feeding power transmission gear 68. It is necessary to convert the rotation into one direction to continue, that is, one of forward rotation and reverse rotation.

  Therefore, the wire feeding mechanism 128 has a forward rotation gear series 131 that transmits while maintaining the rotation direction of the power transmission gear 35, and a transmission mechanism that has a reverse rotation gear series 132 that transmits the rotation direction of the power transmission gear 35 in the reverse direction. 133, the shaft 135 driven by the transmission mechanism 133, the first one-way clutch 136 that transmits the rotation of the forward rotation gear train 131 to the shaft 135 in only one direction, and the first one-way clutch 136 that rotates the reverse rotation gear train 132. A double clutch mechanism 138 that has a second one-way clutch 137 that transmits to the shaft 135 only in the direction opposite to the rotation to transmit, and rotates the shaft 135 only in one direction. The power transmission gear 35 referred to here is a wire-feeding power transmission gear 68.

  FIG. 12 shows the forward rotation gear series 131, and FIG. 13 shows the reverse rotation gear series 132. Here, for each gear of the forward rotation gear series 131 and the reverse rotation gear series 132, the counterclockwise rotation is expressed as normal rotation, and the clockwise rotation is expressed as reverse rotation.

  The first stage gear 131a of the forward rotation gear series 131 and the first stage gear 132a of the reverse rotation gear series 132 are rotationally integrated. Accordingly, if one of the first gear 131a of the forward gear series 131 and the first gear 132a of the reverse gear series 132 is meshed with the power transmission gear 35, that is, the power transmission gear 68 for wire feeding, good.

  The forward rotation gear series 131 includes an even number of gears including the forward rotation series last gear 131 b supported by the shaft 135 via the first one-way clutch 136. Therefore, the forward rotation gear series 131 rotates the forward rotation series last stage gear 131b while maintaining the rotation direction of the power transmission gear 35, that is, the wire feeding power transmission gear 68.

  The reverse gear series 132 includes an odd number of gears including the reverse series last stage gear 132 b supported by the shaft 135 via the second one-way clutch 137. Therefore, the reverse gear series 132 reverses the rotational direction of the power transmission gear 35, that is, the wire feeding power transmission gear 68, and rotates the reverse series final gear 132b.

  In other words, if the wire feed power transmission gear 68 rotates forward, the forward rotation series final gear 131b rotates forward and the reverse rotation series final gear 132b rotates reversely, while the wire feed power transmission gear 68 rotates reverse. Then, the forward rotation series last gear 131b is reversely rotated, and the reverse rotation series last gear 132b is in a forward rotation relationship. The forward rotation series last gear 131b and the reverse rotation series last gear 132b rotate in directions opposite to each other.

  The first one-way clutch 136 transmits the driving force by connecting the forward rotation series last gear 131b and the shaft 135 when the forward rotation series last gear 131b is rotating forward (in FIG. 12). ), When the forward rotation series last gear 131b is rotating in reverse, the forward rotation series last gear 131b is disconnected from the shaft 135 to cause the forward rotation series last gear 131b to idle (FIG. 12). Middle two-dot chain arrow). Similarly, the second one-way clutch 137 transmits the driving force by connecting the reverse rotation series final gear 132b and the shaft 135 when the reverse rotation series final gear 132b is rotating forward (solid line in FIG. 13). Arrow) When the reverse rotation series final gear 132b is rotating in reverse, the reverse rotation series final gear 132b is disconnected from the shaft 135 to cause the reverse rotation series final gear 132b to idle (two-dot chain line in FIG. 13). arrow).

  Further, the description will be made by paying attention to the rotational direction of the power transmission gear 35, that is, the wire feeding power transmission gear 68. When the wire feeding power transmission gear 68 is rotating forward, the first one-way clutch 136 is While the forward rotation series final stage gear 131b and the shaft 135 are connected in rotation and transmit the driving force (solid arrow in FIG. 12), the second one-way clutch 137 The connection between the step gear 132b and the shaft 135 is released, and the reverse rotation series last step gear 132b is idled (two-dot chain arrow in FIG. 13). On the other hand, when the wire feed power transmission gear 68 is reversely rotated, the first one-way clutch 136 releases the connection between the reversely rotated forward rotation last gear 131b and the shaft 135 and rotates forward. While the final gear 131b is idled (two-dot chain arrow in FIG. 12), the second one-way clutch 137 connects the reverse rotation final gear 132b and the shaft 135 that are rotating in the forward direction to transmit the driving force. (Solid line arrow in FIG. 13).

  By the action of the double clutch mechanism 138, the shaft 135 rotates only in one direction, here, the forward rotation direction.

  The first one-way clutch 136 and the second one-way clutch 137 are provided at one end of the shaft 135. The first one-way clutch 136 and the second one-way clutch 137 have the same structure. The first one-way clutch 136 and the second one-way clutch 137 may be a sprag type or a cam type (or a roller type). For example, the roller-type first one-way clutch 136 and the second one-way clutch 137 include an outer race (outer ring, not shown), a roller 147, and a spring 148. The outer race includes a pocket 149 having a cam surface inside. A roller 147 is disposed in the pocket 149. The spring force of the spring 148 brings the roller 147 into contact with the cam surface of the outer ring and the outer peripheral surface of the shaft 135. When the outer ring rotates in one direction with respect to the shaft 135 (forward rotation in the present embodiment), the roller 147 is sandwiched between the outer peripheral surface of the shaft 135 and the cam surface, and the contact surface pressure increases. It becomes resistance and transmits driving force. When the outer ring rotates in the other direction with respect to the shaft 135 (reverse rotation in the present embodiment), the contact surface pressure between the roller 147 and the outer peripheral surface of the shaft 135 and between the roller 147 and the cam surface is reduced and slips. Cut off the transmission of driving force.

  A wire feed roller 146 is provided at the other end of the shaft 135 so as to rotate together. The wire feeding roller 146 is driven by the rotation of the shaft 135 and supplies the wire to the welding torch 19. The shaft 135 rotates in one direction by the action of the wire feeding mechanism 128, and the wire feeding roller 146 also rotates in one direction to supply the wire to the welding torch 19.

  Next, the purge gas supply path of the welding apparatus 1 according to this embodiment will be described.

  FIG. 14 is a longitudinal sectional view showing a purge gas supply path of the welding apparatus according to the present embodiment.

  FIG. 15 is a cross-sectional view showing a purge gas supply path of the welding apparatus according to the present embodiment.

  16 and 17 are cross-sectional views for explaining the operation of the purge gas supply path of the welding apparatus according to the present embodiment.

  As shown in FIG. 14, the welding apparatus 1 according to the present embodiment includes a purge gas supply path 151.

  The purge gas supply path 151 passes through the gas supply port 152 provided in the back surface plate 38 of the base 2 and the central axis of the first gear 21 of any one of the annular gear trains 23 to reach the front surface plate 37 from the back surface plate 38. An introduction pipe 153 and a gas reservoir 155 provided on the front face plate 37 are provided.

  The gas introduction pipe 153 is a flow path that guides the purge gas flowing into the gas supply port 152 to the front face plate 37 of the base 2. The gas introduction pipe 153 also serves as an axis that supports the first gear 21 arranged on the same axis. The gas introduction pipe 153 may also serve as an axis that supports any of the second gears 22 in the annular gear train 23.

  The gas reservoir 155 is a groove-like space that is opened in a direction facing the swivel base 5. The gas reservoir 155 is provided in an annular shape over the entire circumference of the front face plate 37.

  The purge gas supply path 151 includes an annular valve seat 157 having a plurality of gas outlets 156 arranged over the entire circumference of the base 2 and a plurality of valve bodies for opening and closing each of the plurality of gas outlets 156. 158 and an arc-shaped gas relay provided in the swivel base 5 having a gas flow path 159 connected to at least one of the plurality of gas outlets 156 no matter where the swivel base 5 moves. A body 161 and a valve drive mechanism 162 that opens a valve body 158 that closes a gas outlet 156 connected to the gas relay body 161.

  The valve seat body 157 serves as a lid that closes the gas reservoir 155 of the front face plate 37. The valve seat body 157 is also a part of an electric circuit that supplies electric power to the welding torch 19 and is a conductor. Although the valve seat body 157 is fixed to the front face plate 37, the purge gas is prevented from leaking from the gap between the valve seat body 157 and the front face plate 37, and the valve seat body 157 and the front face plate 37 are electrically connected. In order to insulate, an insulating seal plate 163 is sandwiched between the valve seat body 157 and the front face plate 37.

  The inner peripheral surface of the valve seat body 157 closes the gas reservoir 155 of the front face plate 37 and also serves as the valve seat 165 of the gas outlet 156. The valve seat 165 is a circular recess provided on the inner periphery of the valve seat body 157.

  The outer peripheral surface of the valve seat body 157 is in contact with the gas relay body 161 fixed to the swivel base 5 side.

  The valve body 158 is disposed in the gas reservoir 155 of the base 2. The valve body 158 is made of urethane rubber, has a cylindrical shape, and has a hemispherical shape at a tip portion that is a contact portion with respect to the valve seat 165. The valve body 158 is held by a valve body holding frame body 166 provided in the gas reservoir 155, a valve shaft 167 fixed to the valve body holding frame body 166, and a guide bush 168 provided slidably on the valve shaft 167. Has been. Further, the valve body 158 is pressed in the direction of closing the gas outlet 156 by the spring force acting from the coil spring 169.

  The valve body holding frame body 166 serves as a fixture for fixing the valve seat body 157 to the front face plate 37 with the fastening member 171 while being fixed to the front face plate 37 with the fastening member 170. In order to electrically insulate the valve seat body 157 and the front face plate 37, the valve body holding frame body 166 is also an insulator. The valve body holding frame 166 holds the plurality of valve bodies 158 and extends in an arc shape. A plurality of valve body holding frame bodies 166 are provided over the entire circumference of the base portion 2 in the same manner as the valve bodies 158 arranged over the entire circumference of the base portion 2 for each gas outlet 156. The valve seat 157 is divided according to the division of the base 2 so as not to hinder the division of the base 2, and the base 2 can be divided into a plurality of parts in the circumferential direction and arranged on the outer periphery of the workpiece. is there.

  The valve body holding frame body 166 is in contact with and supports the inner peripheral surface of the valve seat body 157, while being narrower than the diameter of the valve body 158 and does not hinder the purge gas flowing into the gas outlet 156.

  The valve shaft 167 is fastened to the valve body holding frame body 166 along the center line of the valve body 158.

  The guide bush 168 is fixed to the valve body 158. The guide bush 168 opens and closes the valve body 158 in conjunction with the valve drive mechanism 162.

  The coil spring 169 is inserted into the valve shaft 167 and the guide bush 168 and is sandwiched between the valve body 158 and the valve body holding frame body 166.

  The gas relay body 161 is also a part of an electric circuit that supplies electric power to the welding torch 19 and is a conductor. The valve seat body 157 and the gas relay body 161 are conductors that are in contact with each other and serve as a part of an electric circuit that supplies power to the welding torch 19. The valve seat body 157 and the gas relay body 161 are electrically connected and kept conductive while the swivel base 5 swivels around the base portion 2. That is, the valve seat body 157 and the gas relay body 161 supply electric power to the welding head 3 that turns with respect to the workpieces 200a and 200b from the base 2 side that is stationary with respect to the workpieces 200a and 200b.

  The gas relay body 161 is fixed to the swivel 5 via an insulator holder 172. The gas relay body 161 is a part of the turntable 5 and turns around the base 2 together with the holder 172. The inner peripheral surface of the gas relay body 161 faces the outer peripheral surface of the valve seat body 157 and covers at least one of the plurality of gas outlets 156 regardless of where the swivel base 5 moves. ing.

  The gas flow path 159 extends from the inner peripheral surface of the gas relay body 161 to the outer peripheral surface, and includes a gas chamber 173 in the holder 172 and the swivel base 5, and a gas tube (not shown) connected to the gas chamber 173. Then, purge gas is supplied to the welding torch 19.

  The valve drive mechanism 162 opens the gas outlet 156 that is covered with the gas relay body 161 and connected to the gas flow path 159 at the moving place of the swivel base 5. It should be noted that the gas outlet 156 that is not moved by the swivel base 5 and is not covered by the gas relay body 161 is closed by a valve body 158 that is pressed against the coil spring 169.

  The valve drive mechanism 162 includes a cam 175 that rotates in contact with the gas relay body 161 as the swivel base 5 moves to open the valve body 158. The cam 175 is provided on a valve opening / closing rod 177 that is rotatably supported by the valve seat body 157 via a sliding bush 176, and has a semicircular cam surface in which a part of the valve opening / closing rod 177 is notched. ing. In a state where the valve body 158 closes the valve seat 165, the cam 175 has the chord portion of the semicircular cam surface abutted against the tip of the guide bush 168. On the other hand, the cam 175 lifts the valve body 158 from the valve seat 165 in accordance with the rotation of the valve opening / closing rod 177 and consequently the rotation of the cam surface.

  The valve opening / closing rod 177 extends through both side surfaces of the valve seat body 157. Both free ends of the valve opening / closing rod 177 protrude from the side surface of the valve seat body 157. A swing arm 178 is provided at one free end of the valve opening / closing rod 177. The swing arm 178 faces the radial direction of the valve opening / closing rod 177 and the radial direction of the base 2.

  Further, the valve drive mechanism 162 includes a swing guide 179 provided on the swivel base 5. The swing guide 179 is a trapezoidal or triangular peak having an inclined surface inclined in the moving direction of the swivel base 5 and projecting from the swivel base toward the base 2 side. A part of the inclined surface of the swing guide 179 and the top of the trapezoid corresponding to the top of the mountain or the apex of the triangle is an interference that moves on the trajectory that interferes with the swing arm 178 as the swivel 5 rotates. It is an area.

  That is, the valve drive mechanism 162 makes the inclined surface of the swing guide 179 contact the swing arm 178 in synchronization with the movement of the swivel base 5, and sets the trapezoidal upper base or triangular apex corresponding to the top of the mountain of the swing guide 179. The swing arm 178 is tilted by the included interference region, the valve opening / closing rod 177 is rotated, and the cam 175 is rotated, so that the valve body 158 is lifted from the valve seat 165 to circulate the purge gas (FIG. 16). Further, when the swivel base 5 moves and the interference between the swing guide 179 and the swing arm 178 is eliminated, the valve drive mechanism 162 closes the valve seat 165 with the valve body 158 to block the purge gas flow. This is due to the action of the spring force of the coil spring 169 pressing the valve body 158 against the valve seat 165 by eliminating the interference between the swing guide 179 and the swing arm 178. The spring force that presses the valve body 158 against the valve seat 165 rotates the cam 175 to return the valve opening / closing rod 177 and the swing arm 178 (FIGS. 14, 15, and 17).

  Next, the power supply system of the welding apparatus 1 according to this embodiment will be described.

  FIG. 18 is a plan sectional view showing a power supply system of the welding apparatus according to the present embodiment.

  FIG. 19 is a longitudinal sectional view showing a power supply system of the welding apparatus according to the present embodiment.

  As shown in FIGS. 18 and 19, the power supply system 181 of the welding apparatus 1 includes a power supply conductor 9 that reaches the front surface plate 37 from the rear surface plate 38 of the base 2. The power supply conductor 9 reaches the front face plate 37 side through the power supply through-hole 11 of the back face plate 38 and is electrically connected to the valve seat body 157 that also serves as a part of the electric path. Of the power supply conductor 9, the longitudinal electrical path 182 extending from the rear face plate 38 to the front face plate 37 is divided into a plurality of, for example, three to ensure a cross-sectional area. Each longitudinal circuit 182 is covered with an insulating sheath 183. The longitudinal circuit 182 is disposed in a space between the pair of adjacent first gears 21 in the annular gear train 23, that is, in a phase where the second gear 22 is disposed.

  The gas relay body 161 that also serves as a part of the electric path is pressed against the valve seat body 157 by a coil spring 185 provided between the swivel base 5 and the gas relay body 161. The coil spring 185 stabilizes the conduction between the gas relay body 161 and the valve seat body 157.

  The welding apparatus 1 according to the present embodiment has a dimension in which any one of the first gear 21 and the second gear 22 causes the backlash between the first gear 21 and the second gear 22 to be substantially zero. As a result, the annular gear train 23 can be smoothly rotated, and the positioning accuracy of the revolving gear 28 and the reciprocating gear 33 meshing with the annular gear train 23 can be increased.

  By the way, when the inventor conducted an experiment with the backlash between all the first gears 21 and the second gears 22 being substantially zero, the annular gear train 23 did not rotate smoothly, and the electric motor (the turning electric motor 15). It has been confirmed that a high load is applied to the torch longitudinal motor 16, the torch perspective motor 17, and the wire feeding / feeding motor 18).

  Further, the inventor applies a conventional gear (Patent Document 2) that includes a first main gear body, a first auxiliary gear body, and a coil spring and does not generate backlash, and is equivalent to an annular gear train 23. Even when the trains are arranged, a high load is applied to the electric motor (the turning motor 15, the torch longitudinal motor 16, the torch perspective motor 17, and the wire feeding / feeding motor 18), and the gear train cannot be smoothly rotated. confirmed.

  And any one of the 1st gear 21 and the 2nd gear 22 has the dimension which makes the backlash of the 1st gear 21 and the 2nd gear 22 substantially zero every other, and the annular gear train 23 It was found that the load on the electric motor (the turning electric motor 15, the torch longitudinal motor 16, the torch perspective motor 17, and the wire feeding / feeding motor 18) can be significantly reduced.

  Further, in the welding apparatus 1 according to the present embodiment, any one of the first gear 21 and the second gear 22 has a backlash greater than zero between the first gear 21 and the second gear 22 every other one. Thus, the annular gear train 23 can be smoothly rotated, and the positioning accuracy of the revolving gear 28 and the reciprocating gear 33 meshing with the annular gear train 23 can be increased.

  Furthermore, the welding apparatus 1 according to the present embodiment smoothly rotates the annular gear train 23 even if either one of the first gear 21 and the second gear 22 has substantially the same dimensions. The positioning accuracy of the revolving gear 28 and the reciprocating gear 33 that mesh with the annular gear train 23 can be improved. This is because the backlash between the first gear 21 and the second gear 22 is reduced to practically zero by preparing substantially two types of dimensions of the second gear 22 and every other one. When a backlash greater than zero is given, the substantial dimensions of all the first gears 21 can be unified, which is highly convenient.

  Furthermore, the welding apparatus 1 according to the present embodiment includes a gear train mechanism 25 having a plurality of annular gear trains 23 including a plurality of first gears 21 and a plurality of second gears 22 that are alternately meshed in a row. Accordingly, the first gear 21 and the second gear 22 having extremely small diameters can be applied as compared with the conventional welding apparatus including the annular gear surrounding the workpieces 200a and 200b, and the machining accuracy of the gear can be easily secured.

  Further, the welding apparatus 1 according to the present embodiment includes a gear train mechanism 25 having a plurality of annular gear trains 23 including a plurality of first gears 21 and a plurality of second gears 22 that are alternately meshed in a ring. Compared with a conventional welding apparatus having an annular gear surrounding the workpieces 200a and 200b, the driving mechanism of the welding head 3 can be made lighter even if the dimensions are applicable to the workpieces 200a and 200b having the same diameter. , Handling convenience can be enhanced. The weight reduction of the driving mechanism of the welding head 3 suppresses the required output of the electric motor 6 and contributes to further weight reduction and cost reduction of the welding apparatus 1.

  Furthermore, in the conventional welding apparatus including the annular gears surrounding the workpieces 200a and 200b, in order to increase the degree of freedom of the welding head 3 (that is, to increase the number of axes) by making the annular gears multistage, the annular gears are simply used. However, the welding apparatus 1 according to the present embodiment has multiple stages such as four rows of annular gear trains 23. Is extremely easy.

  Furthermore, the welding apparatus 1 according to the present embodiment includes a base 2 that is divided into a plurality of portions in the circumferential direction and can be arranged on the outer periphery of the workpiece 200a, so that the welding apparatus 1 can be further attached to the workpiece 200a. Thus, the weight can be reduced and the portability can be improved.

  In addition, the welding apparatus 1 according to the present embodiment includes the power transmission gear 35 that is rotated in two directions according to the forward and backward movements of the reciprocating gear 33, so that the annular gear train is based on the turning gear train 45. 23, that is, torch longitudinal movement gear train 46, torch distance gear train 47 and wire gear train 48 can easily realize multi-axis welding head 3.

  Furthermore, the welding apparatus 1 according to the present embodiment calculates the amount of forward and backward movement of the reciprocating gear 33 by the rotation sensor 92 that detects the rotation of the differential case 82 of the differential gear mechanism 36 to transmit power. The amount of rotation of the gear 35 and hence the amount of movement of the welding head 3 can be determined.

  Furthermore, the welding apparatus 1 according to the present embodiment employs a micro switch as the rotation sensor 92 by making the effective number of internal teeth of the reciprocating gear 33 equal to or less than the number of teeth of the ring gear 83 of the differential gear mechanism 36. In addition, the apparatus can be simplified and the cost can be reduced.

  Therefore, according to the welding apparatus 1 according to the present embodiment, it is possible to secure welding accuracy with exceptionally high processing accuracy in the small-diameter pipe, and in the medium-large-diameter pipe, and the handling convenience is also good. is there.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Welding apparatus 2 Base part 2a, 2b Semicircular arc part 3 Welding head 5 Turntable 6 Electric motor 7 Motor housing 8 Clamp 9 Power supply conductor 11 Power supply through-hole 12 Fixing mechanism 13 Torch holder 15 Turning electric motor 16 Torch longitudinal motor 17 Electric motor 18 Wire feeding / feeding motive 19 Welding torch 21 First gear 22 Second gear 23 Annular gear train 25 Gear train mechanism 27 Internal gear 28 Swivel gear 31 Internal gear 32 External gear 33 Reciprocating gear 35 Power transmission gear 36 Differential gear mechanism 37 Front face plate 38 Back face plate 39 Guide groove 45 Turning gear train 46 Torch longitudinal motion gear train 47 Torch distance gear train 48 Wire gear train 56 Torch longitudinal motion reciprocating gear 57 Torch distance reciprocating gear 58 Wire feeding Reciprocating gear 59 Roller part 61 Torch installation surface 66 Torch longitudinal power transmission gear 67 Torch distance power transmission Gear 68 Power transmission gear 76 for wire feeding Differential gear mechanism for torch longitudinal movement 77 Differential gear mechanism for torch distance 78 Differential gear mechanism for wire 79 Guide hole 81 Guide rod 82 Differential case 83 Ring gear 85 Pinion shaft 86 Pinion gear 87, 88 Side gear 89 Drive shaft 91 Drive gear 92 Rotation sensor 101 Output shaft 102, 103 Gear 105 Shaft 106, 107, 108, 109, 111 Gear 112 Output shaft 113, 115 Gear 126 Torch longitudinal movement mechanism 127 Torch distance movement mechanism 128 Wire Feed mechanism 131 Forward gear train 132 Reverse gear train 131a First gear 132a First gear 131b Forward train last gear 132b Reverse gear last gear 133 Transmission mechanism 135 Shaft 136 First one-way clutch 137 Second gear Way clutch 138 Double clutch mechanism 146 Wire feed roller 147 Roller 148 Spring 149 Pocket 151 Purge gas supply path 152 Gas supply port 153 Gas introduction pipe 155 Gas reservoir 156 Gas outlet 157 Valve seat 158 Valve body 159 Gas flow path 161 Gas Relay body 162 Valve drive mechanism 163 Seal plate 165 Valve seat holding frame body 167 Valve shaft 168 Guide bush 169 Coil spring 170 Fastening member 171 Fastening member 172 Gas chamber 175 Cam 176 Sliding bushing 177 Valve opening / closing rod 178 Swing arm 179 Swing guide 181 Power supply system 182 Longitudinal circuit 183 Sheath 185 Coil springs 200a and 200b Workpiece

Claims (8)

An annular base fixed to the outer periphery of the cylindrical workpiece,
An annular gear train including a plurality of first gears and a plurality of second gears alternately meshing with each other along the base portion;
An arcuate swivel gear having internal teeth meshed with the first gear of the annular gear train;
A swivel base fixed to the swivel gear and movable in the circumferential direction of the base and supporting the welding head;
An electric motor that generates a driving force transmitted to the first gear of the annular gear train,
The second gear has a smaller diameter than the first gear,
A line connecting the rotation centers of the plurality of first gears draws a circle concentric with the base,
A welding device that draws a circle concentric with the base portion, wherein the line connecting the rotation centers of the plurality of second gears . 2. The welding apparatus according to claim 1, wherein the rotation center of each of the second gears is disposed on a line segment that connects the center lines of the pair of first gears adjacent to the second gear. The welding apparatus according to claim 1, wherein at least one of the first gear and the second gear has substantially the same dimensions. There are a plurality of the annular gear trains,
Having the electric motor for each annular gear train;
Internal teeth and external teeth that are engaged with the first gear of any one of the annular gear trains different from the annular gear train that is reciprocally held by the swivel base and meshed with the swivel gears. An arc-shaped reciprocating gear having
4. A welding apparatus according to claim 1, further comprising: a power transmission gear supported by the swivel base and meshed with the external teeth of the reciprocating gear to transmit power to the welding head. 5. The welding apparatus according to any one of claims 1 to 4, wherein the base is divided into a plurality of parts in a circumferential direction and can be arranged on an outer periphery of the workpiece. The welding apparatus according to claim 4, wherein the power transmission gear is rotated in two directions in accordance with forward and backward movement of the reciprocating gear. A differential gear mechanism interposed between the electric motor and the first gear;
A welding device according to any one of claims 1 to 6, further comprising a rotation sensor that detects rotation of a casing of the differential gear mechanism. A differential gear mechanism interposed between the electric motor and the first gear;
A rotation sensor for detecting the rotation of the casing of the differential gear mechanism,
The welding apparatus according to claim 4 or 6, wherein the number of effective teeth of the internal teeth of the reciprocating gear is equal to or less than the number of teeth of the input gear of the differential gear mechanism.

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