JP6307552B2 - Horizontal automatic welding equipment - Google Patents

Description

  The present invention supports a workpiece formed by bending a metal plate such as a stainless steel plate, a steel plate, a copper plate, or an aluminum plate into a cylindrical shape by a horizontal mandrel, and both ends of the workpiece in the circumferential direction on a back bar provided on the mandrel. In connection with the improvement of the horizontal automatic welding equipment that butt welds the TIG welding torch to produce cylinders such as pipes, drums, bellows, etc., especially when the work is set on the mandrel, the lower position of the mandrel The present invention relates to a horizontal type automatic welding apparatus in which a workpiece is supported in a horizontal posture by a liftable table lifter unit disposed on the surface.

  Conventionally, as an apparatus for producing cylindrical bodies such as pipes, drums, and bellows by butt-welding both ends in the circumferential direction of a workpiece made of a metal plate bent into a cylindrical shape, for example, the horizontal developed previously by the present applicant A type automatic welding apparatus is known (for example, see Patent Documents 1 to 3).

  That is, the horizontal type automatic welding apparatus is not shown, but is provided with a frame, a mandrel that is provided in a horizontal posture on the frame and supports a workpiece bent into a cylindrical shape, and a long back bar provided on the mandrel. And a center positioning mechanism that is provided on the mandrel to position both ends of the workpiece in the circumferential direction, a clamp mechanism that presses and fixes the workpiece against both ends in the circumferential direction, and the butting part of the workpiece A welding apparatus having a TIG welding torch for welding, and positioning both ends of the workpiece set on the mandrel in the circumferential direction by a center positioning mechanism and clamping both ends of the positioned workpiece in the circumferential direction Butt-fixed on the back bar using a TIG welding torch and butt-welded the workpiece butt part. Beam, is obtained so as to produce a cylindrical body of bellows or the like.

  By the way, in the horizontal type automatic welding apparatus, when a workpiece bent into a cylindrical shape is set on a mandrel, if the workpiece diameter is relatively small or the workpiece length is short, even one worker may The work can be set on the mandrel.

  However, when a workpiece having a large diameter or a long length is set on the mandrel, it is difficult for one worker to accurately set the workpiece on the mandrel. Therefore, when setting a workpiece with a large diameter or a long length on the mandrel, two workers must stand on both sides of the mandrel and set the mandrel while holding the workpiece in a cylindrical shape. There was a problem that workability was extremely inferior.

  Therefore, in order to solve the above-mentioned problem, the present applicant has developed a horizontal automatic welding apparatus provided with a table lifter unit that supports the work so that it can be raised and lowered in a horizontal posture when the work is set on a mandrel (for example, , See Patent Document 4).

  That is, a table lifter unit 60 of the horizontal type automatic welding apparatus includes a lifter base 61 fixed on a base frame 67 of a frame and a table 62 disposed above the lifter base 61 as shown in FIG. A pair of telescopic arms 63 provided between the lifter base 61 and the table 62 and capable of extending in the vertical direction to support the table 62 so as to be movable up and down, and provided between the lifter base 60 and the telescopic arms 63. A cylinder 64 that extends and retracts the arm 63 in the vertical direction and a work receiving roller 65 that is provided on the table 62 and supports the work in a horizontal posture are provided, and are disposed below the mandrel.

  The pair of telescopic arms 63 is configured to be pivotably connected in a state of crossing the inner arm 63a and the outer arm 63b, and the upper end portion of the inner arm 63a and the lower end portion of the outer arm 63b are the table 62 and the lifter base. The lower end portion of the inner arm 63a and the upper end portion of the outer arm 63b are movably supported by the lifter base 61 and the table 62 via a support roller 66.

  Thus, the horizontal automatic welding apparatus described in Patent Document 4 is provided with a table lifter unit 60 that supports the workpiece in a horizontal posture so that it can be raised and lowered at a lower position of the mandrel. When a long workpiece is set on a mandrel, a single worker can easily and easily set a workpiece having a large diameter or a long workpiece on a mandrel.

  However, the horizontal automatic welding apparatus provided with the table lifter unit 60 still has problems to be solved.

  That is, the horizontal type automatic welding apparatus has a support roller 66 rotatably attached to the lower end portion of the inner arm 63a and the upper end portion of the outer arm 63b constituting the telescopic arm 63 of the table lifter unit 60, and the lower end of the inner arm 63a. The upper support roller 66 is brought into contact with the upper surface of the lifter base 61 in a rollable manner, and the support roller 66 at the upper end of the outer arm 63b is brought into contact with the lower surface of the table 62 in a rollable manner. There has been a problem that rattling is likely to occur between the arm 63 and the lifter base 61 and between the telescopic arm 63 and the table 62, making it difficult to accurately set the work on the mandrel.

  For example, in the horizontal type automatic welding apparatus, when the work is supported in a horizontal posture by the table lifter unit 60 and the work is set on the mandrel, the support roller 66 of the inner arm 63a is lifted from the upper surface of the lifter base 61 at some time. Alternatively, the table 62 may float with respect to the support roller 66 of the outer arm 63b, and each support roller 66 of the telescopic arm 63 may be displaced in a direction perpendicular to the traveling direction of the support roller 66. There was something to say.

  As a result, in the horizontal type automatic welding apparatus, the work supported in a horizontal posture by the table lifter unit 60 is not parallel to the mandrel, and both ends in the circumferential direction of the work are parallel to the traveling locus of the TIG welding torch. It becomes difficult to set the work accurately on the mandrel.

  Further, in the horizontal type automatic welding apparatus, the table lifter unit 60 is disposed on the upper surface of the base frame 67 of the frame, so that the distance between the table lifter unit 60 and the mandrel becomes narrow, and a workpiece having a large diameter can be transferred to the table lifter unit. There was a problem that it could not be supported at 60.

  Further, the horizontal type automatic welding apparatus covers the space between the lifter base and the table with a bellows structure cover (not shown) in order to increase the safety of the operator and prevent accidents. During the maintenance of the unit 60, it is necessary to remove the cover. However, it takes time to remove the cover, and there is a problem that workability is inferior.

JP 2006-051531 A JP 2007-021566 A JP, 2015-160238, A JP 2012-066294 A

  The present invention has been made in view of such problems, and its purpose is to accurately and promptly place a work on the mandrel when setting the work supported by the liftable table lifter unit on the mandrel. It is an object of the present invention to provide a horizontal automatic welding apparatus that can be easily set and can be supported by a table lifter unit even for a workpiece having a large diameter, and can easily perform maintenance of the table lifter unit.

In order to achieve the above object, a horizontal automatic welding apparatus according to the present invention includes a frame including an upper frame and a base frame that protrude in the horizontal direction in the same direction, and is supported by the frame in a horizontal posture and bent into a cylindrical shape. A mandrel parallel to the upper frame that supports the workpiece made of a processed metal plate, a back bar provided on the mandrel, a center positioning mechanism that is provided on the mandrel and positions the circumferential end surface of the work, and an upper frame Clamp mechanism that clamps on the back bar in a state where both ends of the workpiece in the circumferential direction are abutted, a welding device that butt welds the butt of the workpiece, and a workpiece that is provided on the base frame and set on the mandrel In a horizontal type automatic welding apparatus comprising a table lifter unit that supports a vertical lift in a horizontal posture. The table lifter unit includes a lifter base, a table disposed above the lifter base, a pair of lower linear guides disposed on the upper surface of the lifter base along the mandrel, and disposed on the lower surface of the table along the mandrel. A pair of upper linear guides and an inner arm and an outer arm are rotatably connected to each other, and one end portions of the inner arm and the outer arm are rotatably connected to a lifter base and a table, The other end of the inner arm and the outer arm is provided between a pair of telescopic arms that can be expanded and contracted in the vertical direction, connected to the sliders of the lower linear guide and the upper linear guide, and between the lifter base and the pair of telescopic arms. Connect the other end of the arm and outer arm along the guide rails of the lower and upper linear guides. A ball screw mechanism for backward movement, provided on the lifter base, and forward and reverse rotatable motor for operating the ball screw mechanism is provided on the top surface of the table, and a work receiving roller for supporting a workpiece in a horizontal posture, receives the lifter base or work And a roll screen device that is provided on any of the rollers and covers a space between the lifter base and the work receiving roller with a screen that can be pulled out .

  Preferably, the base frame of the frame is formed in a bifurcated shape, and a table lifter unit is disposed between the bifurcated base frames.

  It is preferable to provide an attaching / detaching means for making the tip of the screen detachable from the work receiving roller or lifter base between the tip of the screen of the roll screen device and the work receiving roller or lifter base.

  The attaching / detaching means is preferably a permanent magnet provided at the tip of the screen and attracting and holding the tip of the screen and the work receiving roller or lifter base.

The horizontal automatic welding apparatus according to the present invention has an upper end and a lower end on the movable side of an X-shaped telescopic arm of a table lifter unit that supports a work set on a mandrel, and is placed above the lower surface of the table and the upper surface of the lifter base. Since the telescopic arm is movably attached via a linear guide and a lower linear guide, and the telescopic arm is vertically expanded and contracted by a ball screw mechanism and a motor, the telescopic arm and the table and between the telescopic arm and the lifter base are moved. There is nothing to say that rattling occurs.
As a result, the horizontal automatic welding apparatus according to the present invention is such that when the work supported by the table lifter unit is set on the mandrel, the work is always supported by the table lifter unit in a state parallel to the mandrel. Thus, it becomes easy to set the work on the mandrel accurately and quickly so that the butted portions at both ends in the circumferential direction of the work are parallel to the traveling locus of the TIG welding torch. As a result, it is possible to perform stable welding without welding defects such as melting or piercing at both ends of the butt portion of the workpiece.

  In the horizontal automatic welding apparatus according to the present invention, the base frame of the frame is formed in a bifurcated shape, and the table lifter unit is disposed between the bifurcated base frames. The distance between the table lifter unit and the mandrel can be increased as compared with the conventional horizontal automatic welding apparatus disposed on the upper surface of the frame, and even a workpiece having a large diameter can be supported by the table lifter unit.

  Furthermore, the horizontal type automatic welding apparatus according to the present invention is provided with a roll screen device on either the lifter base or the work receiving roller of the table lifter unit, and the space between the lifter base and the work receiving roller is drawn out from the roll screen device. The screen is covered with a screen, and an attachment / detachment means is provided between the tip of the screen and the workpiece receiving roller or lifter base so that the tip of the screen can be attached to and detached from the workpiece receiving roller or lifter base. Therefore, during the maintenance of the table lifter unit, the screen covering the space between the lifter base and the table can be easily taken up, and the table lifter unit can be maintained quickly and has excellent workability. . In addition, since the attaching / detaching means is constituted by a permanent magnet, the attachment of the tip of the screen to the work receiving roller or the lifter base and the removal from the work receiving roller or the lifter base can be performed with one touch, which is extremely convenient.

1 is a partially omitted front view of a horizontal automatic welding apparatus according to an embodiment of the present invention. It is a partially omitted side view of the horizontal automatic welding apparatus. It is a top view of a horizontal type automatic welding apparatus similarly. It is a vertical front view of a mandrel, a back bar, and a center positioning mechanism. It is a front view of a clamp mechanism and a welding apparatus. It is a front view of a table lifter unit. It is a side view of a table lifter unit. It is a top view of a table lifter unit. It is a partially-omission perspective view of a table lifter unit. It is a perspective view of the principal part of a table lifter unit. It is a vertical side view of the principal part of a table lifter unit. It is a vertical front view of the principal part of a table lifter unit. It is a schematic side view of the table lifter unit used for the conventional horizontal type automatic welding apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 3 show an example of a horizontal automatic welding apparatus according to an embodiment of the present invention. The horizontal automatic welding apparatus bends a metal plate such as a stainless steel plate, a steel plate, a copper plate, or an aluminum plate into a cylindrical shape. A cylindrical body such as a pipe, a drum, or a bellows is produced by butt-welding both circumferential ends of the workpiece W.

  That is, as shown in FIGS. 1 to 3, the horizontal automatic welding apparatus includes a frame 1, a long mandrel 2 supported in a cantilevered state on the frame 1 and supporting a workpiece W, a mandrel 2 at 180 degree intervals, and a long back bar 3 and a thick plate work W (when a thin plate work W (work W having a thickness of 0.2 mm to 0.4 mm) is welded) A long back bar 3 used for welding a workpiece W) having a thickness of 0.5 mm to 2.0 mm, and a mandrel 2 are provided on the mandrel 2. And a pair of center positioning mechanisms 4 for positioning both ends of the workpiece W in the circumferential direction so as to abut each other on the back bar 3 for the thick plate, and a circumference of the workpiece W. With both ends of the direction facing each other. A clamping mechanism 5 for clamping onto the club 3, a welding device 6 provided at a position above the mandrel 2 and having a TIG welding torch 27 for butt welding the butt portion of the workpiece W, and a position below the mandrel 2. The table lifter unit 7 is provided and supports the workpiece W set on the mandrel 2 so as to be movable up and down in a horizontal posture.

As shown in FIGS. 1 to 3, the frame 1 is provided on a box-shaped main body frame 1a and an upper portion of the main body frame 1a, and protrudes from the main body frame 1a forward (to the left in FIG. 2) in a horizontal posture. A scale-shaped upper frame 1b, and a bifurcated base frame 1c that is provided at the lower part of the main body frame 1a, projects in a horizontal posture in the same direction as the upper frame 1b, and is installed on the floor surface. Inside the frame 1a are housed a welding power source, a cooling unit, a gas cylinder for welding such as argon gas, a compressed air supply source such as a compressor (all not shown), and the like.
In FIGS. 1 to 3, 8 is an operation panel, 9 is a pressure / flow rate panel, 10 is a polishing machine for a tungsten electrode rod, 11 is a step, 12 is a caster, and 13 is an adjuster.

  The mandrel 2 is formed of a metal material such as an aluminum alloy, and is connected to a mandrel main body 2a having a substantially octagonal prismatic cross section and a tip of the mandrel main body 2a as shown in FIG. A mandrel receiving tool 2b supported by a mandrel receiving unit 14 provided at the distal end of the upper frame 1b of the frame 1 and a mandrel shaft (not shown) coupled to the base end of the mandrel body 2a and having a circular cross section. I have.

  The mandrel 2 is disposed along the upper frame 1b at a position directly below the upper frame 1b. The mandrel 2 is supported by the main body frame 1a in a cantilevered manner and rotatable about an axis. 3 or the back bar 3 for a thick plate is positioned so as to face right above.

  The mandrel 2 has a mandrel support 2b supported by the mandrel receiving unit 14 at the time of butting work of the workpiece W, welding work, etc., and is in a state of being supported by the main body frame 1a and the mandrel receiving unit 14.

  As shown in FIG. 2, the mandrel receiving unit 14 includes a mandrel receiver 14b that swings from a horizontal position to a vertical position by a rotary actuator 14a, and rotates the mandrel receiver 14b from the horizontal position to the vertical position. By inserting a mandrel pin 2c provided at the tip of the mandrel receiver 2b into a support hole formed in the mandrel receiver 14b, the tip of the mandrel 2 can be supported.

  As shown in FIG. 4, the thin plate back bar 3 and the thick plate back bar 3 are both formed in a long rectangular column shape having a substantially rectangular cross section by a copper material, and are 180 degrees to the mandrel 2. The mounting grooves 2d formed at intervals are fitted and fixed by bolts. These back bars 3 absorb excess heat when butt-welding both ends of the workpiece W in the circumferential direction to prevent the beads from being melted or perforated, the workpiece W being thermally strained, and the like. A shield gas is allowed to flow on the back side of the butt portion to prevent oxidation of the welded portion.

  Further, as shown in FIG. 4, gas grooves 3 a through which shield gas flows are formed along the longitudinal direction of the back bar 3 on the upper surfaces of the thin plate back bar 3 and the thick plate back bar 3. On the bottom surface of the gas groove 3a, a center plate 15 of the center positioning mechanism 4 is inserted in a loosely fitted state, and a through slit groove 3b through which a shield gas flows is formed.

  The pair of center positioning mechanisms 4 are configured in the same structure, and as shown in FIG. 4, a long steel plate is inserted into the slit groove 3 b of the back bar 3 so as to be freely movable up and down. A scale-shaped center plate 15 and a plurality of driving units 16 provided in the mandrel 2 at regular intervals and moving the center plate 15 up and down are provided.

  Further, as shown in FIG. 4, the drive unit 16 is fitted into a piston hole 2e formed in the mandrel 2 so as to be slidable in the vertical direction, and a center piston 16a for supporting the center plate 15, the back bar 3 and the center piston 16a. And a return compression spring 16b that urges the center piston 16a downward and positions the tip of the center plate 15 in the slit groove 3b of the back bar 3. When air is supplied to the piston hole 2e, the center piston 16a and the center plate 15 rise against the elastic force of the compression spring 16b, the tip of the center plate 15 protrudes outward from the upper surface of the back bar 3, When the supply of compressed air is stopped, the center piston 16a and the elastic force of the compression spring 16b Centers plate 15 is lowered and the tip portion of the center plate 15 is adapted to be housed in the slit groove 3b.

  The clamp mechanism 5 clamps the work W inserted in the mandrel 2 on the back bar 3 in a state where both ends of the work W are butted in the circumferential direction. The both ends of the workpiece W in the circumferential direction are abutted while increasing / decreasing the clamp pressure of the W with a minute pressure of about 0.001 MPa to 0.002 MPa. 3 After confirming the state of being pressed onto the workpiece, the workpiece W is pressed with a pressure force that can withstand deformation due to welding heat (high pressure force of about 0.2 MPa to 0.5 MPa). Are controlled so that both ends in the circumferential direction can be securely and satisfactorily clamped on the back bar 3.

  That is, the clamp mechanism 5 includes a clamp base 17 fixed to the lower surface of the upper frame 1b, a pair of left and right fixing bases 18 fixed to the lower surface of the clamp base 17, and a horizontal surface on the lower surface of the clamp base 17, as shown in FIG. The mandrel 2 is disposed so as to be movable toward the mandrel 2 in a posture, and is supported by a pair of long left and right movable bases 19a along the mandrel 2 and swingable in the vertical direction via hinges 20 on each of the movable bases 19a. A pair of long left and right movable plates 19b along 2 and a lower surface of each movable plate 19b is provided so as to be slightly swingable in the vertical direction, and arranged in an opposing manner in a posture along the mandrel 2. Between the pair of long copper left and right clamp plates 21 that can come into contact with the upper surfaces of both ends in the circumferential direction of the workpiece W supported by the mandrel 2, and between the pair of movable plates 19b and the pair of clamp plates 21. Setting In addition, a buffering coil spring (not shown) that biases the distal ends of the pair of clamp plates 21 downward, a pair of fixed bases 18 and a pair of movable bases 19a, and a pair of movable bases 19a. The screw screw 22 that horizontally moves the pair of movable plates 19b and the pair of clamp plates 21, and the screw screws 22 are rotated to move the pair of movable bases 19a and the pair of movable bodies horizontally. The clamp width adjusting knob 23 for adjusting the distance between the pair of clamp plates 21 and the clamp base 17 and the pair of movable plates 19b are interposed between the pair of movable plates 19b and 19b. A pair of left and right air tubes 24 that swings the pair of clamp plates 21 downward, and a movable plate 19b that is built in each movable plate 19b and urges the movable plate 19b upward to swing downward. 19b a and a return coil spring to return to a horizontal position (not shown).

As shown in FIGS. 1 to 3 and 5, the welding apparatus 6 is a traveling platform disposed on the upper surface of the upper frame 1 b so as to be reciprocally movable in the longitudinal direction of the mandrel 2 via two parallel guide rails 25. 26, a welding torch 27 that is supported by the traveling table 26 so as to be movable up and down, allows a shielding gas such as argon gas to flow from the tip, and has a tungsten electrode rod 27a inserted therein, and a welding torch provided on the traveling table 26. A torch vertical drive device (not shown) composed of a servo motor or the like for moving up and down 27 and a traveling table 26, which facilitates the setting of the gap between the tungsten electrode rod 27a and the workpiece W before welding is started. An electrode contact detection device (not shown) that immediately detects a contact accident between the tungsten electrode rod 27a and the workpiece W, and a mode in which the traveling table 26 reciprocates in the longitudinal direction of the mandrel 2. And a traveling drive device (not shown in the figure) composed of a motor and a transmission mechanism. When the butt portion of the workpiece W is butt welded, the tip of the welding torch 27 is automatically adjusted in height, The welding torch 27 supported thereby moves linearly along the butt portion of the workpiece W at a predetermined speed.

  Further, the welding torch 27 is provided with a TIG in which a constricting nozzle (not shown) for flowing a part of the shielding gas as a high-speed rectifying gas is inserted around the arc generated between the tungsten electrode rod 27a and the workpiece W. A welding torch is used.

  The table lifter unit 7 supports the workpiece W so that it can be raised and lowered in a horizontal posture when welding a workpiece W having a large diameter or a workpiece having a long length. As shown in FIGS. A lifter base 28 provided on 1c, a table 29 disposed above the lifter base 28, a pair of lower linear guides 30 provided on the upper surface of the lifter base 28, and a pair of upper linears provided on the lower surface of the table 29. A guide 31, a pair of telescopic arms 32 provided between the lifter base 28 and the table 29, which can extend and contract in the vertical direction to support the table 29 so as to be movable up and down, and a ball screw mechanism 33 that expands and contracts the pair of telescopic arms 32. And a motor 34 that can rotate forward and reverse to operate the ball screw mechanism 33, and a table 29, and the workpiece W is placed in a horizontal posture. A work receiving roller 35 to lifting, provided the lifter base 28, and a rolling screen device 36 that covers between the lifter base 28 and the table 29.

  Specifically, the lifter base 28 is formed in a rectangular shape by a metal plate, and is positioned between the base frames 1c formed in a bifurcated shape so as to be substantially the same height as the lower surface of the base frame 1c. The frame 1c is fixedly supported in a horizontal posture. Therefore, as shown in FIG. 6, the table lifter unit 7 is arranged between the bifurcated base frame 1c when the table 29 and the work receiving roller 35 are lowered, and the table lifter unit 7 and the mandrel 2 are arranged. And a workpiece W having a large diameter can be supported by the table lifter unit 7.

  In addition, a pair of lower linear guides 30 are fixed to the upper surface of the lifter base 28 on the tip portion side (the upper surface on the left side of the lifter base 28 in FIG. 7) in a posture along the mandrel 2 with a certain interval. The pair of lower linear guides 30 includes a guide rail 30a, a slider 30b that is movably attached to the guide rail 30a, and a rolling element (not shown) interposed between the guide rail 30a and the slider 30b. Yes.

  The table 29 is formed in a rectangular shape by a metal plate, and is disposed in a horizontal position and along the mandrel 2 above the lifter base 28.

  In addition, a pair of upper linear guides 31 are fixed to the lower surface on the tip end side of the table 29 (the lower left surface of the table 29 in FIG. 7) in a posture along the mandrel 2 with a certain interval. The pair of upper linear guides 31 includes a guide rail 31a, a slider 31b movably attached to the guide rail 31a, and a rolling element (not shown) interposed between the guide rail 31a and the slider 31b. Yes.

  The pair of telescopic arms 32 is configured such that the inner arm 32a and the outer arm 32b intersect with each other in an X shape and are rotatably connected by a bolt 32c and a nut 32d, and one end portions of the inner arm 32a and the outer arm 32b are lifters. The other ends of the inner arm 32a and the outer arm 32b are rotatably connected to the base 28 and the table 29, respectively, and are respectively connected to the sliders 30b and 31b of the lower linear guide 30 and the upper linear guide 31. Has been.

  That is, as shown in FIG. 7, the upper end of the inner arm 32a is connected to the upper bracket 37 provided on the lower surface on the base end side of the table 29 (the lower right side of the table 29 in FIG. 7) via the fixed upper connection shaft 38. As shown in FIGS. 6, 7, and 9, the lower end of the inner arm 32 a is connected to the lower arm, and is fixed to the ball screw base 33 c of the ball screw mechanism 33 provided on the slider 30 b of the lower linear guide 30. It is connected to 39 through a movable side lower connecting shaft 40 so as to be rotatable.

  Further, as shown in FIGS. 7 and 9, the lower end of the outer arm 32b is connected to the lower bracket 41 provided on the upper surface on the base end side of the lifter base 28 (the upper surface on the right side of the lifter base 28 in FIG. 7). As shown in FIGS. 6, 7, 10, and 11, the upper end of the outer arm 32b is connected to an upper connecting bracket 43 fixed to the slider 31b of the upper linear guide 31. It is connected via a movable side upper connecting shaft 44 so as to be rotatable.

  As shown in FIG. 9, the ball screw mechanism 33 is provided between the lifter base 28 and the inner arms 32 a of the pair of telescopic arms 32, and is fixed to a pair of upper surfaces of the tip end portion and the intermediate portion of the lifter base 28. The support unit 33a is fixedly supported by a pair of support units 33a, a ball screw shaft 33b supported in a posture along the lower linear guide 30 and not movable in the axial direction, and a slider 30b of the pair of lower linear guides 30, A ball screw shaft 33 b is rotatably inserted, and a lower end portion of the inner arm 32 a is provided with a ball screw base 33 c that is rotatably connected via a lower connection fitting 39 and a movable side lower connection shaft 40.

  According to this ball screw mechanism 33, when the ball screw shaft 33b is rotated forward and backward by the motor 34, the ball screw base 33c and the slider 30b of the pair of lower linear guides 30 reciprocate along the ball screw shaft 33b and the guide rail 30a. Accordingly, the lower end of the inner arm 32a connected to the ball screw base 33c reciprocates along the guide rails 30a of the pair of lower linear guides 30, and the pair of extendable arms 32 expands and contracts in the vertical direction. Become.

  As shown in FIG. 9, the motor 34 is attached to a motor bracket 45 fixed to the upper surface of the intermediate portion of the lifter base 28, and an output shaft thereof is linked to a ball screw shaft 33 b via a coupling 46. A stepping motor is used as the motor 34.

  Therefore, when a predetermined number of pulse input signals are applied to the motor 34, the output shaft of the motor 34 performs stepping rotation according to the number of input pulses, and this rotational motion is caused by the ball screw shaft 33b of the ball screw mechanism 33 via the coupling 46. Thus, the ball screw shaft 33b is rotated forward or backward by a predetermined angle or a predetermined number of rotations.

  In this embodiment, as shown in FIGS. 6 to 8, a stepping motor is used as the motor 34. However, any type of motor may be used as long as the rotation angle can be controlled. For example, a servo motor (DC motor + encoder), an AC servo motor (AC motor + encoder), or an ultrasonic motor may be used.

  The work receiving roller 35 includes a long roller receiving table 35a disposed on the upper surface of the table 29 of the table lifter unit 7 in a posture along the mandrel 2, and a roller receiving table 35a along the mandrel 2 at regular intervals. A plurality of ball rollers 35b mounted in four rows and having 360 ° rotatable balls, and the ball rollers 35b arranged in four rows along the mandrel 2 are provided on the lower surface of the outer peripheral surface of the workpiece W. The work W is brought into contact with and supported from the lower surface side.

  The roll screen device 36 is provided on each of two longitudinal sides of the lifter base 28 and a tip side of the lifter base 28, and covers the space between the lifter base 28 and the table 29 so as to be openable and closable. This is to ensure the safety of workers.

  That is, each roll screen device 36 is fixed to the lifter base 28 as shown in FIGS. 6, 7 and 9, and a support plate 47 provided with side plates 47b facing each other at both ends of a long base plate 47a. The take-up pipe 48 rotatably supported by the side plate 47b of the support plate 47 and the base end portion are connected to the take-up pipe 48, and can be taken up by the take-up pipe 48 or pulled out from the take-up pipe 48. A non-flammable or flame retardant screen 49, a winding coil spring (not shown) that is built in the winding pipe 48, and that exerts a force to rotate the winding pipe 48 in the direction in which the screen 49 is always wound. A support pipe 50 attached to the tip of the screen 49 to prevent the screen 49 from being deformed, and the screen 4 Of it provided at the distal end portion, and a detachable unit 51 which can be removably mounted to the distal end portion of the screen 49 relative to the roller cradle 35a of the work receiving roller 35.

  Further, as shown in FIG. 11 and FIG. 12, the attaching / detaching means 51 is provided at predetermined intervals on a support pipe 50 attached to the tip of the screen 49, and a roller cradle 35a of the work receiving roller 35 and the tip of the screen 49. Are composed of a plurality of permanent magnets that are attracted and held by magnetic force. These permanent magnets are provided with positioning pins 52 for positioning the position of the screen 49 by being inserted into positioning holes formed on the lower surface of the roller receiving table 35 when attracted and held by the roller receiving table 35.

  In the above embodiment, the roll screen device 36 is provided on the lifter base 28. However, in other embodiments, the roll screen device 36 is provided on the roller receiving base 35a of the work receiving roller 35, and the tip of the screen 49 is provided. The part and the lifter base 28 may be detachable from the attaching / detaching means 51. Alternatively, a part of the roll screen device 36 is provided on the lifter base 28, and the other roll screen device 36 is attached to the roller receiving base 35a of the work receiving roller 35. It may be provided.

  Next, a case where a cylindrical body such as a pipe, a drum, or a bellows having a large diameter is manufactured by butt-welding both circumferential ends of a workpiece W bent into a cylindrical shape using the horizontal automatic welding apparatus described above will be described. .

  First, the mandrel 2 is manually rotated according to the thickness of the workpiece W to be butt welded, and the mandrel 2 is rotated so that the back bar 3 corresponding to the thickness of the workpiece W faces directly above.

  Next, the tip of the mandrel 2 is supported by the mandrel receiving unit 14 to prevent the long mandrel 2 from being bent, and in this state, the center plate 15 of the center positioning mechanism 4 located on the upper surface side of the mandrel 2 is driven. The upper end portion of the center plate 15 is protruded upward from the upper surface of the back bar 3 by being raised by the portion 16.

  Thereafter, the workpiece W bent into a cylindrical shape is placed in a horizontal posture on the workpiece W receiving roller 35 of the table lifter unit 7 with its circumferential ends facing upward, and the workpiece W is inserted into the mandrel 2 from the workpiece receiving roller 35. The height of the work receiving roller 35 is adjusted by the telescopic arm 32, the ball screw mechanism 33 and the motor according to the diameter of the work W so that the work W can be attached, and the work W on the work receiving roller 35 is inserted into the mandrel 2.

  In this way, since the workpiece W is inserted into the mandrel 2 using the table lifter unit 7, even if the workpiece W has a large diameter or has a long length, the workpiece W can be attached to the mandrel 2 by one worker. Can be inserted.

Further, the movable upper end (upper end of the outer arm 32 b) and lower end (lower end of the inner arm 32 a) of the X-shaped telescopic arm 32 of the table lifter unit 7 are used as the lower surface of the table 29 and the upper surface of the lifter base 28. The upper and lower linear guides 31 and 30 are attached so as to be movable, and the telescopic arm 32 is vertically expanded and contracted by the ball screw mechanism 33 and the motor 34. There will be no backlash between the telescopic arm 32 and the lifter base 28.
As a result, the workpiece W is supported by the table lifter unit 7 in a state of being always parallel to the mandrel 2, and the workpiece W can be easily and accurately set on the mandrel 2.

  When the work W is inserted into the mandrel 2, the pair of clamp plates 21 of the clamp mechanism 5 are lowered, and the pair of clamp plates 21 lightly press both circumferential ends of the work W onto the back bar 3. Clamp to such an extent that both ends in the circumferential direction can move on the back bar 3.

  After clamping both ends of the workpiece W in the circumferential direction so as to move on the back bar 3, one end of the workpiece W in the circumferential direction is brought into contact with the side surface of the upper end portion of the center plate 15, and one end in the longitudinal direction of the workpiece W is fixed. Pressing against the start tab 53 provided at the base end of the mandrel 2, the pressure of one clamp plate 21 (the clamp plate 21 positioned above one end of the work W abutted against the center plate 15) is set to 0 in this state. A high pressure force of about 2 MPa to 0.5 MPa is used, and one end portion in the circumferential direction of the work W is firmly clamped so as not to move onto the back bar 3.

  When one end of the workpiece W in the circumferential direction is brought into contact with the center plate 15, one end portion of the workpiece W in the circumferential direction can move between the back bar 3 and the tip of the one clamp plate 21. Since it is clamped, it will be abutted against the center plate 15 while being guided by the tip of the clamp plate 21 and the back bar 3, and it becomes easy to abut against the center plate 15.

  When one end in the circumferential direction of the work W is brought into contact with the center plate 15 and firmly clamped, the supply of compressed air supplied to the drive unit 16 of the center positioning mechanism 4 is stopped. Then, the center plate 15 is lowered by the elastic force of the return compression spring 16b, and the upper end of the center plate 15 is accommodated in the slit groove 3b of the back bar 3.

  When the center plate 15 is lowered, the other end in the circumferential direction of the workpiece W is first pressure-fixed on the back bar 3 by visual observation while changing the applied pressure of the other clamp plate 21 of the clamp mechanism 5 with a minute pressure. The workpiece W is brought into contact with one end in the circumferential direction. That is, the abutting operation of both ends in the circumferential direction of the workpiece W is performed while increasing / decreasing the pressure of the other clamp plate 21 by about 0.001 MPa to 0.002 MPa.

  At this time, since the abutting operation of both ends in the circumferential direction of the workpiece W is performed while finely adjusting the pressing force of the clamp plate 21 with a minute pressure, even when the thickness or material of the workpiece W changes, The circumferential end can be reliably and satisfactorily clamped to such an extent that it can move between the clamp plate 21 and the back bar 3. As a result, regardless of the thickness and material of the workpiece W, the other end in the circumferential direction of the workpiece W can be reliably and satisfactorily matched without causing a gap at one end in the circumferential direction of the workpiece W and without overlapping. Can do.

  Then, after confirming that the other end of the workpiece W in the circumferential direction is abutted without causing a gap at one end in the circumferential direction of the workpiece W without overlapping, the pressure of the other clamp plate 21 is set to 0. A high pressure force of about 2 MPa to 0.5 MPa is used, and one end portion in the circumferential direction of the work W is firmly clamped so as not to move onto the back bar 3.

  When both ends in the circumferential direction of the workpiece W are abutted and fixed on the back bar 3, while supplying a shielding gas such as argon gas from the gas supply port (not shown) of the mandrel 2 into the slit groove 3b of the back bar 3, The butt portion of the workpiece W is butt welded by the welding device 6.

  That is, the welding torch 27 is lowered so that the tip of the tungsten electrode rod 27 a faces the surface of the start tab 53 on the base end side of the mandrel 2, and in this state, between the tungsten electrode rod 27 a and the start tab 53. An arc is generated, and after the arc becomes stable, the traveling platform 26 is advanced by a drive device (not shown) to cause the welding torch 27 to travel along the butt portion of the workpiece W at a predetermined speed. The butt portion of W is sequentially butt welded.

  At this time, both ends of the workpiece W in the circumferential direction are abutted with no gap and are pressed on the back bar 3 by the clamp mechanism 5 at a high pressure of 0.2 MPa to 0.5 MPa, thereby preventing deformation due to welding heat. And no poor welding such as perforation occurs.

  When the butt welding of the workpiece W is completed, the supply of the shielding gas to the back bar 3 is stopped, and the welding torch 27 of the welding apparatus 6 returns to the original position. Further, the pressing state of the workpiece W against the back bar 3 by the clamp mechanism 5 is released, and the mandrel receiver 14b is rotated from the vertical position to the horizontal position to open the tip of the mandrel 2.

  Thereby, the workpiece | work W by which butt welding was carried out will be in a free state, and the workpiece | work W can be extracted from the mandrel 2. FIG. In this manner, pipes, drums, bellows and other cylindrical bodies are produced from the workpiece W bent into a cylindrical shape.

  1 is a frame, 1b is an upper frame, 1c is a base frame, 2 is a mandrel, 3 is a back bar, 4 is a center positioning mechanism, 5 is a clamp mechanism, 6 is a welding device, 7 is a table lifter unit, 28 is a lifter base, 29 is a table, 30 is a lower linear guide, 30a is a guide rail, 30b is a slider, 31 is an upper linear guide, 31a is a guide rail, 31b is a slider, 32 is a telescopic arm, 32a is an inner arm, 32b is an outer arm, 33 Is a ball screw mechanism; 34 is a motor; 35 is a work receiving roller; 36 is a roll screen device; 49 is a screen;

Claims (4)

A frame (1) having an upper frame (1b) and a base frame (1c) projecting horizontally in the same direction, and a workpiece made of a metal plate supported by the frame (1) in a horizontal posture and bent into a cylindrical shape The mandrel (2) parallel to the upper frame (1b) supporting (W), the back bar (3) provided on the mandrel (2), and the circumferential direction of the work (W) provided on the mandrel (2) A center positioning mechanism (4) for positioning the end face of the workpiece and a clamp mechanism provided on the upper frame (1b) for clamping the workpiece (W) on the back bar (3) in a state where both ends of the workpiece (W) are in contact with each other (5), welding device (6) that butt welds the butt portion of the workpiece (W), and the workpiece (W) that is provided on the base frame (1c) and set on the mandrel (2) can be moved up and down in a horizontal posture. In the horizontal type automatic welding apparatus including a supporting table lifter unit (7), the table lifter unit (7) includes a lifter base (28) and a table (29) disposed above the lifter base (28). ), A pair of lower linear guides (30) disposed on the upper surface of the lifter base (28) along the mandrel (2), and a pair of lower linear guides (30) disposed on the lower surface of the table (29) along the mandrel (2). The upper linear guide (31), the inner arm (32a) and the outer arm (32b) are rotatably connected to each other, and one end portions of the inner arm (32a) and the outer arm (32b) are lifter bases. (28) and the table (29) are rotatably connected, and the other ends of the inner arm (32a) and the outer arm (32b) are lower linear. A pair of telescopic arms (32) that can be expanded and contracted in the vertical direction connected to the sliders (30b) and (31b) of the id (30) and the upper linear guide (31), a lifter base (28), and a pair of telescopic arms ( 32) and the other ends of the inner arm (32a) and the outer arm (32b) along the guide rails (30a) and (31a) of the lower linear guide (30) and the upper linear guide (31). A reciprocating ball screw mechanism (33), a lifter base (28), a motor (34) capable of rotating forward and reverse, which operates the ball screw mechanism (33), and a table (29). A workpiece receiving roller (35) that supports (W) in a horizontal posture, and provided on either the lifter base (28) or the workpiece receiving roller (35). A horizontal automatic welding apparatus , comprising: a roll screen device (36) covered with a screen (49) capable of pulling out a space between the support (28) and the work receiving roller (35) .   The horizontal frame according to claim 1, wherein the base frame (1c) of the frame (1) is bifurcated and a table lifter unit (7) is disposed between the bifurcated base frame (1c). Automatic welding equipment. Between the tip of the screen (49) of the roll screen device (36) and the workpiece receiving roller (35) or lifter base (28), the tip of the screen (49) is placed between the workpiece receiving roller (35) or lifter base. The horizontal automatic welding apparatus according to claim 1 , further comprising an attachment / detachment means (51) that is attachable / detachable to / from (28) . The attachment / detachment means (51) is provided at the tip of the screen (49), and comprises a permanent magnet that attracts and holds the tip of the screen (49) and the work receiving roller (35) or the lifter base (28). The horizontal automatic welding apparatus according to claim 3 , wherein:

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