JP2011016186A - Polishing device for electrode and automatic system for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing device for an electrode and an automatic system for the same, which suppresses swaying of an electrode during polishing, and promptly corresponds to polishing work of an electrode of each welding machine even when the plurality of welding machines are installed.SOLUTION: The polishing device 1 including a file 3 formed with abrasive grain faces on the front and back, a cylinder 4 linearly reciprocating the file 3 in a direction orthogonal to an electrode axial direction, a floating mechanism 5 allowing the movement of the file 3 in the electrode axial direction by a reaction force received from a fixed electrode, and a movable electrode guide member 7 bored with a movable electrode guide hole 6 inserted with the tip periphery of a movable electrode and suppressing the swaying of the movable electrode during polishing is attached to a robot arm R1 moving in three dimensions, and both electrodes are polished by pressing the file 3 against the fixed electrode by the robot arm R1 and pressing the file 3 against the movable electrode by a pressurizing cylinder.

Description

  The present invention relates to a polishing apparatus for polishing an electrode of a welding machine and an automatic system thereof.

  A conventional example of an apparatus for simultaneously polishing a movable electrode and a fixed electrode of a projection welder is disclosed in Patent Document 1. This document describes a technique in which a pair of files are pressed against a movable electrode and a fixed electrode, respectively, and both files are polished simultaneously by reciprocating the files with a cylinder.

Japanese Patent Laid-Open No. 10-6034

  If the electrode is formed to have a small diameter or a long length, the electrode is liable to shake during polishing, and the electrode may be plastically deformed depending on the degree of the pressure contact force received from the file.

  In addition, when a plurality of welding machines are installed at the welding site, it is extremely uneconomical to prepare a polishing apparatus for each machine, and thus a method of using one polishing apparatus is usually employed. However, this method has a problem that it takes time for the polishing operation because the operator sets the polishing apparatus for each machine each time.

  The present invention was created in order to solve such problems, and can suppress the deflection of the electrodes during polishing, and even when a plurality of welding machines are installed, the polishing operation of the electrodes of each welding machine It is an object of the present invention to provide an electrode polishing apparatus and an automatic system thereof that can respond quickly.

  In order to solve the above problems, the present invention is an apparatus for simultaneously polishing a movable electrode and a fixed electrode of a welding machine, the apparatus being attached to a robot arm that performs a three-dimensional operation, and forming an abrasive surface on both sides And a drive source that linearly reciprocates the file in a direction perpendicular to the electrode axis direction, a floating mechanism that allows the file to move in the electrode axis direction by the reaction force received from the fixed electrode, and the periphery of the tip of the movable electrode A movable electrode guide member having a movable electrode guide hole formed therein, which suppresses the deflection of the movable electrode during polishing. The robot arm presses the file against the fixed electrode and the pressure cylinder removes the movable electrode. Both electrodes are polished by being pressed against each other.

  According to the present invention, even when a large lateral force is applied from the file to the movable electrode during polishing, vibration around the tip of the movable electrode is suppressed by the movable electrode guide hole. Therefore, even when the movable electrode is formed with a small diameter or a long length, plastic deformation can be prevented.

  The present invention is further characterized by further comprising a fixed electrode guide member that is inserted around the tip of the fixed electrode and in which a fixed electrode guide hole that suppresses the deflection of the fixed electrode during polishing is formed.

  The fixed electrode in contact with the plate material side is often formed with a larger diameter than the movable electrode in contact with the nut side, and although the degree of deflection is smaller than that of the movable electrode, the fixed electrode is provided by providing a fixed electrode guide member. Can be reliably prevented.

  The present invention is characterized in that a plurality of movable electrode guide holes having different diameters are formed in the movable electrode guide member in accordance with a diameter specification of the movable electrode.

  According to the present invention, by providing a plurality of movable electrode guide holes of different diameters, for example, a polishing apparatus that can easily cope with a change in the diameter specification of the movable electrode in one welding machine. .

  Further, the present invention is a system using an electrode polishing apparatus in which a plurality of movable electrode guide holes having different diameters are formed in the movable electrode guide member in accordance with the diameter specification of the movable electrode, and the operation of the robot arm Multiple welding machines with different movable electrode diameter specifications are installed within the range, and the robot arm is controlled so that the movable electrode guide hole that matches each diameter specification is located directly below the movable electrode of each welding machine. It is characterized by performing.

  According to the present invention, even when a plurality of welding machines having different diameter specifications of the movable electrode are installed, it is possible to quickly cope with each welding machine with one polishing apparatus.

  According to the present invention, even when a large lateral force is applied from the file to the movable electrode during polishing, vibration around the tip of the movable electrode is suppressed by the movable electrode guide hole. Therefore, even when the movable electrode is formed with a small diameter or a long length, plastic deformation can be prevented.

It is a side view which shows the layout of the robot provided with the polishing apparatus of the electrode which concerns on this invention, and a welding machine. It is a top view which shows the layout of the robot provided with the polishing apparatus of the electrode which concerns on this invention, and a welding machine. 1 is an external perspective view of an electrode polishing apparatus according to the present invention. It is a sectional side view of the polisher of the electrode concerning the present invention. 1 is a front sectional view of an electrode polishing apparatus according to the present invention. It is explanatory drawing of the limit switch which detects the abrasion state of a movable electrode. It is explanatory drawing of the abrasion loss measuring apparatus of a fixed electrode. It is a side view which shows the state which replaced with the grinding | polishing apparatus and attached the board | plate material adsorption | suction apparatus to the robot arm.

  As shown in FIG. 1, the polishing apparatus 1 according to the present invention is attached to the tip of an articulated robot arm R1 that performs a three-dimensional operation. Specifically, the polishing apparatus 1 of the robot arm R1 is connected via a rotating unit 2. It is attached to the tip. The rotation unit 2 includes a first disk part 2A and a second disk part 2B that are rotated relative to each other by a drive source (not shown). The first disk part 2A is fixed to the tip of the robot arm R1, and the second disk part. The polishing apparatus 1 is attached to 2B. A series of movements of the robot arm R1 at the time of polishing is controlled so that, for example, the first disk portion 2A is positioned upward with respect to the rotation unit 2 and the posture in which the rotation axis direction is vertical is maintained. In the description of the structure, the rotation unit 2 is assumed to be based on the posture, that is, based on the posture of the rotation unit 2 shown in FIG.

  The robot arm R1 has a function of conveying the plate material to be welded to the projection welder 51 during the welding process. The first disc portion 2A and the second disc portion 2B are configured to be detachable. In the welding process, as shown in FIG. 8, a plate material adsorbing device 56 that adsorbs the plate material W by the vacuum pad 55 is provided in the robot arm R1. It is attached to the tip.

  In the projection welding machine 51, a movable electrode 53 that can be moved up and down by a pressurizing cylinder 52 is attached to an upper portion of the front surface, and a fixed electrode 54 is attached to a lower portion of the front surface. In the present embodiment, as shown in FIG. 2, a plurality of projection welders 51 are installed within the operating range of the robot arm R <b> 1, and a plurality of projection welders 51 are arranged along the circumferential direction centering on the installation location of the robot body R. Projection welding machines 51 are arranged in parallel. A plurality of projection welders 51 may be laid out in a straight line or the like as long as they are within the operating range of the robot arm R1, and in this case, since the distance between the robot body R and each projection welder 51 is different, the robot arm R1 is controlled according to each distance.

  3 to 5, a polishing apparatus 1 includes a file 3 having an abrasive grain surface 3A formed on the front and back, a drive source (cylinder 4) for linearly reciprocating the file 3 in a direction orthogonal to the electrode axis direction, A floating mechanism 5 that allows the file 3 to move in the electrode axial direction by a reaction force received from the electrode 54, and a movable electrode guide hole 6 that passes around the tip of the movable electrode 53 and suppresses the deflection of the movable electrode 53 during polishing. A movable electrode guide member 7 provided with a hole and a fixed electrode guide member 9 provided with a fixed electrode guide hole 8 that is inserted around the tip of the fixed electrode 54 and suppresses the vibration of the fixed electrode 54 during polishing. The main component.

  Hereinafter, a structural example of the polishing apparatus 1 will be described. A rectangular support plate 10 is fixed to the lower surface of the second disk portion 2B, and four support pillars 11 arranged in a square shape are suspended and fixed to the lower surface of the support plate 10. Each support column 11 is formed with a small diameter around the center in the vertical direction, and a horizontal base plate 12 is attached to the support column 11 so as to be movable up and down through four through holes fitted in the respective small diameter portions. In each small diameter portion, both ends of the spring are supported by the first compression coil spring 13 in which both ends of the spring are supported by the base plate 12 and the upper large diameter portion of the column 11, and the lower large diameter portion of the base plate 12 and the column 11. The second compression coil spring 14 is fitted. That is, the base plate 12 is attached to the column 11 in a form that is elastically supported from above and below by the first compression coil spring 13 and the second compression coil spring 14. The first compression coil spring 13 and the second compression coil spring 14 constitute the floating mechanism 5.

  The base plate 12 has a substantially rectangular shape, and one end side in the longitudinal direction is located immediately below the support plate 10, and the other end side is located so as to extend outward from one side of the support plate 10 in plan view. is doing. The file 3 is provided on the extended portion of the base plate 12. The base plate 12 is provided with an escape hole 15 for allowing the fixed electrode 54 to pass therethrough, and a fixed electrode guide member 9 made of a rectangular flat plate is fixed to the upper surface of the base plate 12 so as to straddle the escape hole 15. The The escape holes 15 are continuously drilled up to the cylinder 4 side and have a function of escaping the cylinder 4.

  A plurality (five in this embodiment) of fixed electrode guide holes 8 are formed in the fixed electrode guide member 9 along the reciprocating direction of the file 3. On the other hand, the movable electrode guide member 7 is opposed to the upper surface of the fixed electrode guide member 9 with a thickness equal to or greater than the thickness of the file 3, and a plurality of (five in the present embodiment) coaxial with each fixed electrode guide hole 8. From a shape having a movable electrode guide portion 7A in which a movable electrode guide hole 6 is formed, and a pair of legs 7B that are suspended from both sides of the movable electrode guide portion 7A and fixed to the base plate 12 by bolts or the like. Become.

  Among the plurality of projection welders 51 shown in FIG. 2, the arbitrary plural machines have different diameter specifications of the movable electrode 53 in accordance with the size and shape of the workpiece such as a nut, and the plurality of movable electrode guide holes 6 Are drilled at different diameters so as to meet any diameter specification. Since the fixed electrode 54 side that comes into contact with the lower surface of the plate material W (FIG. 8) has the same diameter, all of the plurality of fixed electrode guide holes 8 have the same diameter. The diameters of the movable electrode guide hole 6 and the fixed electrode guide hole 8 are slightly larger than the diameters of the electrodes to be inserted.

  The file 3 is a plate-like member having a substantially rectangular shape in plan view, and one end of the file 3 is connected to the tip of the rod 4A of the cylinder 4 so as to be rotatable around a connecting shaft 16 in the vertical direction. Since both sides of the file 3 are guided by the leg portions 7B of the movable electrode guide member 7, the file 3 does not swing around the connecting shaft 16 during reciprocal movement. The abrasive grain surface 3A is composed of, for example, diamond abrasive grains, and is formed only at the center in the width direction of the file 3 where the movable electrode 53 and the fixed electrode 54 are in contact with each other, as shown in FIG. ing. As shown in FIG. 4, the cylinder 4 is located immediately below the support plate 10 and is attached to the base plate 12 via a bracket 17. The cylinder 4 is an air cylinder, for example.

  In FIG. 3, a compressed air supply hose (not shown) is built in the robot arm R <b> 1, and the compressed air is taken out from the second disk portion 2 </ b> B by the air tube 18. A part of the compressed air flowing in the air tube 18 is supplied to the surface of the file 3 through the movable electrode guide portion 7A through the three-necked tube 19 as shown in FIG. 5, and the abrasive powder on the file 3 is blown. To do. The periphery of the tip of the air tube 18 is fixed to the upper surface of the movable electrode guide portion 7A, and the tip opening 20 faces the edge of the movable electrode guide portion 7A.

  As shown in FIG. 3, a limit switch 21 is attached to the outer surface of one leg 7B. The limit switch 21 has a function of detecting the wear state of the movable electrode 53 as shown in FIG. At the time of detection, the robot arm R1 (FIG. 1) always stops at a predetermined absolute position so that the tip of the limit switch 21 is located below the electrode surface of the movable electrode 53. At this time, the movable electrode 53 is worn down so much. If not, the tip of the limit switch 21 is pressed against the electrode surface of the movable electrode 53 as shown in FIG. When the movable electrode 53 is extremely worn as shown in FIG. 6B, the electrode surface and the limit switch 21 are not in contact with each other, so that the wear state of the movable electrode 53 is within an allowable range. It is detected that

  Next, the wear amount measuring device 22 for the fixed electrode 54 will be described with reference to FIGS. 3 and 7. 7A and 7B are a front view and a side sectional view of the wear amount measuring device 22, respectively. A contact-type displacement sensor 24 is attached to the upper surface of one side edge of the support plate 10 with a sensor rod 25 facing downward via an attachment plate 23. A pair of guide columns 26 having a flange 26 </ b> A formed at the lower end are suspended and fixed to the lower surface of the support plate 10. It is attached to move up and down. As shown in FIG. 7, the elevating member 27 is a plate-like member having a crank shape in cross section, and the front end side of the elevating member 27 extends outward from the side of the support plate 10. A third compression coil spring 28 is externally fitted to the guide column 26, and both ends of the spring are supported by the lower surface of the support plate 10 and the upper surface of the elevating member 27. The member 27 is always urged downward, and is normally at the lowest point position pressed against the flange 26A as shown in the left diagram of FIG. A notch 29 is provided in the middle of the elevating member 27 to prevent interference with the displacement sensor 24, and a notch edge 29 </ b> A facing upward is in contact with the lower end of the sensor rod 25.

  The wear amount measuring device 22 has the above-described configuration. At the time of measurement, the robot arm R1 (FIG. 1) always stops at a predetermined absolute position by pressing the periphery of the tip of the elevating member 27 against the electrode surface of the fixed electrode 54. . 7B, the elevating member 27 rises against the urging force of the third compression coil spring 28 due to the reaction force received from the fixed electrode 54, and the notch edge 29A is the sensor rod. The upward displacement amount is detected by the displacement sensor 24 by pressing and moving 25 upward, and the wear amount of the fixed electrode 54 is determined from the detected data. Of course, as the wear of the fixed electrode 54 increases, the amount of displacement of the elevating member 27 decreases. The read data is sent to the control panel 30 attached to the support plate 10.

  Hereinafter, the operation of the polishing apparatus 1 will be described. The robot arm R1 extends toward the projection welding machine 51 to be polished. First, as a stage before polishing, the front end 20 of the air tube 18 faces the fixed electrode 54, and the electrode surface of the fixed electrode 54 is blown with compressed air. To do. Of course, the surface of the file 3 is also continuously blown through the three-necked tube 19.

  After the blow processing of the fixed electrode 54 is completed, the robot arm R1 is operated, and the polishing apparatus 1 is inserted between the movable electrode 53 and the fixed electrode 54 at the ascending position. When the movable electrode guide hole 6 that matches the diameter specification of the movable electrode 53 to be polished is located immediately below the movable electrode 53, the lateral movement of the polishing apparatus 1 is finished first.

  Next, the polishing apparatus 1 is lowered by a predetermined stroke by the operation of the robot arm R 1, and the abrasive grain surface 3 A on the back side of the file 3 is pressed against the electrode surface of the fixed electrode 54 through the escape hole 15 and the fixed electrode guide hole 8. At that time, when the floating mechanism 5 operates appropriately, specifically, the first compression coil spring 13 is compressed and the second compression coil spring 14 is extended by the reaction force received from the fixed electrode 54 in the file 3. As a result, the base plate 12 rises and excessive pressing of the file 3 against the fixed electrode 54 is prevented.

  Next, the movable electrode 53 is lowered by the operation of the pressurizing cylinder 52 and is brought into pressure contact with the abrasive grain surface 3 </ b> A on the surface side of the file 3 through the movable electrode guide hole 6. Of course, the pressure cylinder 52 at this time is in a passive state having elasticity, and excessive pressurization of the movable electrode 53 against the file 3 is prevented.

  Then, the file 3 is reciprocated a predetermined number of times (about 4 or 5 times) by the operation of the cylinder 4, and polishing is performed in a state where the electrode surfaces of the movable electrode 53 and the fixed electrode 54 are pressed together by the front and back abrasive surface 3A. Is done. The abrasive powder is blown by compressed air from the air tube 18. Even when a large lateral force is applied from the file 3 to the movable electrode 53 and the fixed electrode 54 during the polishing, the movable electrode 53 and the fixed electrode 54 are respectively provided around the tips of the movable electrode guide hole 6 and the fixed electrode guide. Since they are fitted in the holes 8, the guide electrodes suppress the swing of the movable electrode 53 and the fixed electrode 54, and there is no possibility of causing plastic deformation of the electrodes.

  When the file 3 is reciprocated a predetermined number of times, the movable electrode 53 is raised by the operation of the pressurizing cylinder 52, and then the polishing apparatus 1 is also lifted by the operation of the robot arm R1 to be detached from the fixed electrode. Next, for example, by operating the robot arm R <b> 1, the distal end 20 of the air tube 18 faces the fixed electrode 54, and the electrode surface of the fixed electrode 54 is blown with compressed air.

  Then, the robot arm R1 and the rotary unit 2 are operated to press the periphery of the tip of the elevating member 27 against the electrode surface of the fixed electrode 54, and the wear amount of the fixed electrode 54 is measured by the wear amount measuring device 22. The measured value of the wear amount of the fixed electrode 54 is transmitted to a robot controller (not shown) via the control panel 30 and used for feedback in the next welding process. That is, the robot controller controls the robot arm R1 based on the measured value so that the plate material W adsorbed by the plate material adsorption device 56 is always applied to the electrode surface of the fixed electrode 54 in the next welding process.

  When the measurement of the wear amount of the fixed electrode 54 is completed, the tip of the limit switch 21 is applied to the electrode surface of the movable electrode 53 by the operation of the robot arm R1, and the wear state of the movable electrode 53 is detected. When the switch is not turned on, that is, when the wear state of the movable electrode 53 exceeds the allowable range, a warning sound or a warning light is activated to prompt the operator to replace the movable electrode 53.

  When the detection of the wear state of the movable electrode 53 is completed, the robot arm R1 operates toward the projection welding machine 51 to be polished next, and thereafter performs the same polishing operation and electrode wear measurement.

  The preferred embodiment of the polishing apparatus 1 according to the present invention has been described above. The present invention is not limited to the form described in the drawings, and various design changes can be made without departing from the spirit of the present invention.

1 Electrode Polishing Device 3 File 3A Abrasive Surface 4 Cylinder (Drive Source)
DESCRIPTION OF SYMBOLS 5 Floating mechanism 6 Movable electrode guide hole 7 Movable electrode guide member 8 Fixed electrode guide hole 9 Fixed electrode guide member 51 Projection welding machine 52 Pressurizing cylinder 53 Movable electrode 54 Fixed electrode R Robot main body R1 Robot arm

Claims (4)

An apparatus for simultaneously polishing a movable electrode and a fixed electrode of a welding machine,
The device is attached to a robot arm that performs a three-dimensional movement,
A file with abrasive surfaces on the front and back,
A drive source for linearly reciprocating the file in a direction perpendicular to the electrode axis direction;
A floating mechanism that allows the file to move in the axial direction of the file by the reaction force received from the fixed electrode;
Around the tip of the movable electrode is inserted, a movable electrode guide member having a movable electrode guide hole that suppresses the swing of the movable electrode during polishing, and
An electrode polishing apparatus comprising: a pressure-cylinder for pressing a movable electrode against a file while polishing the electrodes with a robot arm.   2. The electrode polishing according to claim 1, further comprising a fixed electrode guide member having a fixed electrode guide hole that is inserted through the tip of the fixed electrode and that suppresses fluctuation of the fixed electrode during polishing. apparatus.   The electrode polishing apparatus according to claim 1, wherein a plurality of movable electrode guide holes having different diameters are formed in the movable electrode guide member in accordance with a diameter specification of the movable electrode. A system using the electrode polishing apparatus according to claim 3,
Within the operating range of the robot arm, a plurality of welding machines with different diameter specifications of the movable electrode are installed,
An automatic system for an electrode polishing apparatus, wherein a robot arm is controlled so that a movable electrode guide hole corresponding to each diameter specification is positioned directly below a movable electrode of each welding machine.

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