JP6325609B2 - Butt welding equipment - Google Patents

Description

  The present invention relates to a butt welding apparatus.

  Conventionally, materials (plate materials) such as aluminum, nickel, titanium, inconel, stainless steel, and copper are often used for expansion joints (bellows) and cylindrical containers. The cylindrical part of bellows and cylindrical containers is mainly manufactured by roll-bending a cut plate material, butting both ends in the circumferential direction of the tubular workpiece that has been roll-bended, and welding the butted parts Is done.

  As a butt welding apparatus used for this type of welding, for example, a number of horizontal automatic welding machines have been proposed by the present inventors (Patent Documents 1 to 7 and the like).

  For example, as shown in FIG. 4, a conventional butt welding apparatus includes a bar-shaped mandrel 1 that extends in the horizontal direction, a guide rail 3 that extends along the mandrel 1 and travels a welding torch 2, and a workpiece cradle 4 that can be moved up and down. An operation panel 5 and the like are provided.

  As shown in FIG. 5, the mandrel 1 includes a backing metal 6 in which a slit 6a extending along the butt welding direction is formed, and a center plate 7 that is driven up and down from the slit 6a.

  Further, as shown in FIG. 5, the conventional butt welding apparatus has a pair of swingably supported so as to extend parallel to the direction in which the slit 6a extends on both sides of the slit 6a and to move the slit side tip up and down. The clamps 8a and 8b, the welding torch 2 that travels in the butt welding direction, the pair of elastic members 10 that bias the slit-side tips of the pair of clamps 8a and 8b upward, and the pair of clamps 8a. , 8b are provided with a pair of pneumatic expansion-type pressing bodies 11a, 11b that respectively push down the slit-side tip portions downward against the elastic force of the elastic member 10. As the pneumatic expansion pressing bodies 11a and 11b, flexible hoses whose ends are sealed are used.

  The butt work is performed by extrapolating the tubular workpiece W which has been subjected to roll bending to the mandrel 1, with both ends of the tubular workpiece W being butted on the backing metal 6 provided on the mandrel 1. The welding torch 2 is moved along the butt portion of the cylindrical workpiece W in a state where the vicinity of the edge is pressed and clamped on the backing metal 6 by a pair of clamps 8a and 8b, and butt welding is performed to produce a cylindrical product. .

  In such a butt welding apparatus, the circumferential end edges of the cylindrical workpiece W on the backing metal 6 are backed up in the gap between the circumferential ends of the cylindrical workpiece extrapolated to the mandrel 1. The center plate 7 which can be moved up and down from the central upper surface of the gold 6 is driven to rise, and one end edge of the cylindrical workpiece W in the circumferential direction is visually observed so that there is no gap in the center plate 7. One clamp 8a is lowered from above near the edge of the cylindrical workpiece W that is in contact with the center plate 7 in this state, and the cylindrical workpiece W on the side that is in contact with the center plate 7 is lowered. The vicinity of one edge in the circumferential direction is pressed and fixed (main clamp). The center plate 7 is lowered and buried in the backing metal 6 in a state where the vicinity of one circumferential edge of the cylindrical workpiece W is pressed and fixed by one clamp 8a. Next, the other edge of the cylindrical workpiece W is pressed by hand while visually observing the one edge of the cylindrical workpiece W pressed and fixed by the one clamp 8a so that there is no gap. Thereafter, the other clamp 8b waiting upward is lowered and the vicinity of the other circumferential edge of the cylindrical workpiece W is pressed and fixed (main clamp), thereby completing the butt operation.

  Instead of the pneumatic drive type clamp mechanism as described above, a butt welding apparatus has been proposed in which the servo motor 30 moves the clamps 8a and 8b up and down as shown in FIG. 6 (Patent Document 4).

  Servo motor-driven clamps 8a and 8b have a main clamp pressure that fixes both ends of the cylindrical workpiece W so that it does not move, and a temporary holding clamp pressure that holds lightly enough to move on the backing metal 6. Can be switched in two stages. In the butt work, first, the center plate 7 is protruded, both clamps 8a and 8b are used as temporary pressing clamp pressures, and the vicinity of both ends of the cylindrical workpiece W on both sides of the center plate 7 is temporarily pressed. One edge in the circumferential direction of W is manually pressed while visually observing the center plate 7 with no gap. When one circumferential edge of the cylindrical workpiece W is pressed against the center plate 7 with no gap, the one clamp 8a is switched to the main clamping pressure, and the cylindrical workpiece W pressed against the center plate 7 is pressed. Fix one circumferential edge so that it does not move. Thereafter, the center plate 7 is lowered and the other circumferential edge of the cylindrical workpiece W clamped with the temporary holding clamp pressure is manually moved toward the one circumferential edge that is clamped. Move it so that there is no gap. Thereafter, the other clamp 8b is switched to the main clamp pressure to complete the butt operation.

JP 2006-51531 A Japanese Patent Laid-Open No. 2007-21565 JP 2010-137267 A JP 2012-66294 A JP, 2015-160238, A Japanese Patent No. 5044325 Japanese Patent No. 5893198

  However, diversification of materials, ultrathinning of metal plates (for example, thickness of 0.2 to 0.5 mm), and lengthening (for example, of 1600 mm and more) have progressed, and the butt work between metal plate edges is one person. The work is difficult and requires a high level of skill, and it is difficult to make a close contact without any gap.

  Especially when the set pressure of the clamp is only 0 (zero) and the maximum (main clamp pressure) as in the conventional pneumatic drive clamp, when the workpiece is long, for example, 1600 mm, it is from end to end at once. It is difficult to meet without gaps.

  On the other hand, even if the clamping pressure is switched between the main clamping pressure and the temporary pressing clamp pressure as in the conventional servo motor type, the appropriate temporary pressing clamping pressure differs depending on the plate thickness. Matching by work is still difficult.

  In particular, the temporary holding clamp pressure can be slid against the frictional resistance without damaging or deforming the workpiece, and can be moved to the position before the movement by the restoring force due to the leaf spring elasticity of the workpiece after the movement. A pressing force that prevents the return and maintains the position after the movement is preferable.

  It is possible to adjust the temporary pressing clamp pressure in a stepless manner by using a servo motor, but the workpiece may be damaged by excessively increasing the clamping pressure, and it was adjusted to an appropriate temporary pressing clamp pressure. However, if the clamp pressure is high, there is no absorption due to air compression as in the air tube system, so there is a risk that the work will not be slid and the work may be damaged or deformed when you try to slide it. was there.

  Therefore, the main object of the present invention is to provide a butt welding apparatus that is easy to butt even by one person without requiring skill even if it is a long thin plate.

  In order to achieve the above object, a butt welding apparatus according to the present invention includes a backing metal 6 formed with a slit extending in the butt welding direction, a center plate for moving out and out of the slit, and both sides of the slit. A pair of clamps that extend parallel to the direction in which the slits extend and are swingably supported so that the slit side tip ends up and down, a welding torch that runs along the gap between the pair of clamps, and the pair A pair of elastic members for respectively energizing the slit-side tip portions of the clamps upward, and a pair of push-down members for pressing the slit-side tip portions of the pair of clamps downward against the elastic force of the elastic members While supplying compressed air of this clamp pressure set in the range of 0.2-0.4 MPa to a pneumatic expansion type press body and a pair of said pneumatic expansion type press bodies, a pair of said pair Characterized in that it comprises a stepwise can be increased and decreased air pressure circuit, the one of the air pressure in the pressure inflatable pressing member for each predetermined small pressure 0.001～0.002MPa.

  The pneumatic circuit includes a pressure-increasing foot switch for stepwise increasing the air pressure of the pneumatic expansion-type pressing body for each minute pressure, and the air pressure of the pneumatic expansion-type pressing body for gradually decreasing the micro-pressure. It is preferable to include a pressure-reducing foot switch for carrying out and a main-clamping foot switch for outputting compressed air having the main-clamping pressure.

  The pneumatic circuit adjusts the supplied compressed air to a pressure proportional to the input signal and outputs the pressure to the pair of pneumatic expansion-type pressing bodies, respectively, and the operation signal of the clamp foot switch In response, the voltage signal corresponding to the main clamp pressure is output as an input signal to both of the pair of electropneumatic regulators, and the minute pressure is set according to an operation signal from the pressure increasing foot switch and the pressure reducing foot switch. It is preferable to include a programmable controller that calculates a voltage signal corresponding to the increased or decreased pressure and outputs the voltage signal as an input signal to one of the pair of electropneumatic regulators.

  According to the present invention, by adjusting the pressure of the clamp to increase or decrease in small increments, even a long thin plate does not require skill, and one person can easily perform a butt operation.

It is a fragmentary sectional front view which expands and shows the principal part of the butt welding apparatus which concerns on this invention. FIG. 2 is a partially enlarged front view showing a part of FIG. 1 in an enlarged manner. It is a pneumatic circuit block diagram which shows one Embodiment of the pneumatic circuit which is a component of the butt welding apparatus which concerns on this invention. It is a side view which shows the external appearance of the conventional butt welding apparatus. It is a fragmentary sectional front view which expands and shows the principal part of the one aspect | mode of the conventional butt welding apparatus. It is a fragmentary sectional front view which expands and shows the principal part of the other one aspect | mode of the conventional butt welding apparatus.

  An embodiment of a butt welding apparatus according to the present invention will be described below with reference to FIGS. In addition, the same code | symbol was attached | subjected to the same or similar component including a prior art example.

  1 and 2, the butt welding apparatus includes a backing metal 6 formed with slits 6a extending in the butt welding direction, a center plate 7 for protruding and retracting from the slits 6a, and slits 6a. A pair of clamps 8a and 8b that extend in parallel with the direction in which the slit 6a extends on both sides and are swingably supported so that the tip end on the slit side moves up and down, and an electrode along the gap X between the pair of clamps 8a and 8b A welding torch 2 on which 2a runs, a pair of elastic members 10 (only one is shown) for urging the slit side tips of the pair of clamps 8a and 8b upward, and a slit side of the pair of clamps 8a and 8b A pair of pneumatic expansion-type pressing bodies 11a and 11b are provided, each of which pushes the front end portion downward against the elastic force of the elastic member 10.

  The welding torch 2 holds a tungsten electrode 2a, and this butt welding apparatus is a TIG welding apparatus. As the pneumatic expansion pressing bodies 11a and 11b, flexible hoses with both ends sealed can be used as in the conventional case. The butt welding apparatus is a so-called horizontal automatic welding measure that includes a mandrel 1 and is used for butt welding of a bellows or a container outer cylinder, and a backing metal 6 is mounted on the upper part of the mandrel 1. The mandrel 1, the backing metal 6, the center plate 7, the clamps 8a and 8b, the elastic member 10 (only one is shown), and the pneumatic expansion-type pressing bodies 11a and 11b are the same as those of the conventional horizontal automatic welding apparatus. Description is omitted.

  The butt welding apparatus supplies a pair of pneumatic expansion pressing bodies 11a, 11b to the pair of pneumatic expansion pressing bodies 11a, 11b while supplying compressed air having a main clamping pressure P1 set in a range of 0.2 to 0.4 MPa. And an air pressure circuit 20 (FIG. 3) capable of increasing or decreasing the air pressure of at least one of 11b stepwise for each predetermined minute pressure P2 of 0.001 to 0.002 MPa.

  As shown in FIG. 3, the pneumatic circuit 20 includes a pressure-increasing foot switch 21 for stepwise increasing the air pressure of the pneumatic expansion-type pressing bodies 11a and 11b for each minute pressure P2, and the pneumatic expansion-type pressing bodies 11a and 11b. The pressure reducing foot switch 22 for stepwise reducing the air pressure for each minute pressure P2 and the main clamping foot switch 23 for outputting the compressed air of the main clamping pressure P1 are provided.

  Furthermore, the pneumatic circuit 20 adjusts the compressed air supplied from the compressed air source 24 such as a compressor to a pressure proportional to the input signals Sa and Sb, and outputs a pair of electric powers to the pneumatic expansion press bodies 11a and 11b, respectively. Upon receiving the operation signals of the empty regulators 25a and 25b and the main clamp foot switch 23, a voltage signal corresponding to the main clamp pressure P1 is output as an input signal to both the pair of electropneumatic regulators 25a and 25b, and the pressure increasing foot A programmable controller PLC that calculates a voltage corresponding to the pressure obtained by increasing or decreasing the minute pressure P2 in accordance with operation signals from the switch 21 and the pressure-reducing foot switch 22, and outputs the voltage as an input signal Sb only to one electropneumatic regulator 25b; It is equipped with.

  As the electropneumatic regulator 25, a known electropneumatic regulator can be used, and for example, it can be obtained from SMC Corporation.

  The operation procedure in the case of butt welding the cylindrical workpiece W using the butt welding apparatus including the pneumatic circuit 20 will be described. First, the center plate 7 is raised, and the butt edge of the workpiece to be butt welded is set. One edge is pressed against the center plate 7 by hand, and the foot switch 23 for the clamp is stepped on.

  An operation signal generated by stepping on the clamp foot switch 23 is input to the programmable controller PLC, and the programmable controller PLC applies voltages corresponding to the main clamp pressure P1 to the electropneumatic regulators 25a and 25b as input signals Sa and Sb. input.

  Receiving the input signals Sa and Sb, the electropneumatic regulators 25a and 25b adjust the compressed air to the main clamping pressure P1 and output the compressed air to the pneumatic expansion-type pressing bodies 11a and 11b, respectively. The clamps 8a and 8b (see FIGS. 1 and 2) are oscillated by increasing the internal pressure of the pneumatic expansion-type pressing bodies 11a and 11b to the clamp pressure P1, and the respective slit side tips are center plates 7. , And the main workpiece is clamped by clamps 8a and 8b in the vicinity of both ends in the circumferential direction of the cylindrical workpiece W. The “main clamp” in the present invention is a clamp with a pressing force that can withstand deformation of the workpiece due to welding heat, and the “main clamp pressure” is a pressure at the time of main clamping. The clamp pressure varies depending on the thickness of the workpiece, and can be set by inputting in advance to the programmable controller PLC through input means such as a touch panel.

  After the vicinity of both ends in the circumferential direction of the cylindrical workpiece W is clamped, the center plate 7 is lowered below the butted portion of the cylindrical workpiece W. The center plate 7 is located immediately below the track on which the torch 2a travels. Therefore, the butt edge of the cylindrical workpiece W pressed against the center plate 7 is directly below the travel track of the torch 2, that is, the tungsten electrode 2a. positioned.

  In this state, by operating the pressure-reducing foot switch 22 and the pressure-increasing foot switch 21, the pressure of the other clamp 8 b that has not been pressed against the center plate 7 is finely adjusted in small increments to make a tubular shape. The circumferential edge of the workpiece W that is not fully clamped is manually moved toward the circumferential edge on the side that is clamped, and both circumferential edges of the cylindrical workpiece W are moved. Adhere.

  That is, the programmable controller PLC inputs the input signals Sa and Sb corresponding to the main clamp pressure to the electropneumatic regulators 25a and 25b, respectively, when the main clamp foot switch 21 is stepped on. However, when the programmable controller PLC receives a stepping operation signal from the pressure-increasing foot switch 22 and the pressure-reducing foot switch 23, only the input signal Sb to be sent to the other electropneumatic regulator 25b, the pressure-increasing foot switch 22 and the pressure-reducing foot switch. A voltage corresponding to the pressure increased or decreased from the clamp pressure is output as an input signal to the electropneumatic regulator 25b in accordance with the number of times of stepping 23. For example, when the depressurization foot switch 23 is depressed five times and the pressure increase foot switch 22 is depressed twice, the programmable controller PLC calculates the clamp pressure as P1-5P2 + 2P2, and outputs a voltage corresponding to the calculated clamp pressure as the input signal Sb. To the electropneumatic regulator 25b. The minute pressure P2 can be preset in the programmable controller PLC.

  The fine adjustment of the pressing force of the other clamp 8b by the pressure-reducing foot switch 22 and the pressure-increasing foot switch 21 resists frictional resistance without damaging or deforming the workpiece, particularly in the case of butt welding of the cylindrical workpiece W. One workpiece butt edge can be slid and moved toward the other workpiece butt edge, and the workpiece butt edge moved by the restoring force due to the leaf spring elasticity of the cylindrical workpiece W is It is possible to adjust the pressure to an appropriate temporary pressure that prevents the return to the position before the movement and maintains the position after the movement. In this way, by setting an appropriate temporary holding pressure, even a long cylindrical workpiece can be properly matched by one person over the entire length by sequentially abutting from one end to the other end in the welding direction of the workpiece. Easy to do.

  After the proper contact between the butt edges to be welded is completed, the foot switch 23 for the clamp is stepped on again, the other clamp 8b is also used as the clamp pressure, and the welding torch 2 is lowered to the vicinity of the butt portion, By running while generating an arc, the butt portion of the workpiece is welded.

  As described above, by finely adjusting the pressing force of the other clamp 8b stepwise, it becomes possible to set the pressing force optimal for the close contact of the workpiece butt end edges. However, it is possible to perform an accurate contact butting operation without deforming or damaging the workpiece.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

2 Welding torch 6 Backing metal 6a Slit 7 Center plate 8 Clamp 10 Elastic members 11a and 11b Pneumatic expansion type pressing body 20 Pneumatic circuit 21 Pressure increasing foot switch 22 Pressure reducing foot switch 23 This clamp foot switch 25a and 25b Electropneumatic regulator PLC Programmable controller

Claims (3)

A backing metal formed with a slit extending along the butt welding direction;
A center plate for moving in and out of the slit;
A pair of clamps that are swingably supported on both sides of the slit so as to extend in parallel with the direction in which the slit extends and so that the slit-side tip portion moves up and down;
A welding torch that travels along the gap between the pair of clamps;
A pair of elastic members for urging the slit-side tips of the pair of clamps upward;
A pair of pneumatic expansion-type pressing bodies that respectively push down the slit-side tips of the pair of clamps downward against the elastic force of the elastic member;
While supplying the compressed air of this clamp pressure set in the range of 0.2-0.4 MPa to the pair of pneumatic expansion type pressing bodies, the air pressure of one of the pair of pneumatic expansion type pressing bodies is set to 0.001 to 0.001. A butt welding apparatus, comprising: a pneumatic circuit that can be increased or decreased stepwise for each predetermined minute pressure of 0.002 MPa.   The pneumatic circuit includes a pressure-increasing foot switch for stepwise increasing the air pressure of the pneumatic expansion-type pressing body for each minute pressure, and the air pressure of the pneumatic expansion-type pressing body for gradually decreasing the micro-pressure. The butt welding apparatus according to claim 1, further comprising: a pressure-reducing foot switch for performing the operation and a main-clamping foot switch for outputting the compressed air having the main-clamping pressure.   The pneumatic circuit adjusts the supplied compressed air to a pressure proportional to the input signal and outputs the pressure to the pair of pneumatic expansion-type pressing bodies, respectively, and the operation signal of the clamp foot switch In response, the voltage signal corresponding to the main clamp pressure is output as an input signal to both of the pair of electropneumatic regulators, and the minute pressure is set according to an operation signal from the pressure increasing foot switch and the pressure reducing foot switch. 3. A programmable controller that calculates a voltage signal corresponding to the increased or decreased pressure and outputs the voltage signal as an input signal to one electropneumatic regulator of the pair of electropneumatic regulators. Butt welding equipment.