JP5322003B2 - Resistance welding gun - Google Patents

Description

  This invention is a resistance welding gun for pressurizing a material to be welded by a pair of electrodes, supplying a welding current within a short period of time, and melting and joining a welding local part by resistance heating. In particular, the present invention relates to a so-called X-type resistance welding gun in which a movable arm having an electrode attached to the tip is pivotally attached to a rotation shaft.

  Conventionally, resistance welding has been widely used to weld between thin metal plates. This resistance welding is generally used as a welding technique in the automobile manufacturing process because it has a small thermal strain and a uniform welding result can be obtained in a short time.

  In this resistance welding, a resistance welding gun configured to be directly operated by an operator or to be automated by being attached to the tip of a robot arm is well known. The structural classification of this resistance welding gun is roughly divided into a C-type gun and an X-type gun.

  In general, an X-type gun includes a pair of gun arms, one or both of which are pivotally attached to a rotation shaft, and a pair of electrodes attached to the tip are brought into contact with or separated from each other by rotating one or both of the gun arms. It has been adopted.

  As such an X-type gun, for example, Patent Document 1 includes a pair of gun arms, one of which is pivotally attached to a rotating shaft, and an electric motor as a drive unit is in a direction perpendicular to the rotating shaft of the gun bracket. There is disclosed an X gun which is disposed on one side of the gun bracket and has a transformer for supplying a welding current disposed behind the gun bracket (opposite to the side where the pair of gun arms are attached).

Further, Patent Document 2 includes a pair of gun arms, both of which are pivotally attached to a rotating shaft, and an electric motor as a driving unit and a transformer for supplying a welding current are in a direction perpendicular to the rotating shaft of the gun bracket. An X gun is disclosed which is arranged on one side of the gun bracket and the arrangement of the electric motor can be changed.
JP-A-10-71476 Japanese Patent Laid-Open No. 11-267850

  In recent automobile manufacturing processes, it has become commonplace to carry out high-mix low-volume production with short delivery times. Under such circumstances, as a function required for the resistance welding gun, a function of simultaneously operating a plurality of resistance welding guns and simultaneously welding a plurality of adjacent locations is required in order to shorten the welding process.

  In order to weld such a plurality of close locations at the same time, it is necessary to reduce the number of protrusions from the gun bracket or the like so that a plurality of resistance welding guns can be disposed close to each other. However, in the X-type gun shown in Patent Document 1, an electric motor is disposed on one side of the gun bracket, and a part of the transformer disposed on the rear side and a conductive portion extending from the transformer are disposed on the other side. Since the secondary conductor is arranged, there is a problem in that it cannot be placed close to each other.

  Moreover, in the X-type gun shown in Patent Document 2, an electric motor and a transformer are arranged on one side of the gun bracket, and there is almost no protrusion on the other side. Closer arrangement is possible than a type gun. However, in order to place the two resistance welding guns closer together, the opposing side surfaces of the two resistance welding guns (one side of the first resistance welding gun and the other side of the second resistance welding gun) There should be no protrusions. In this regard, in the X-type gun of Patent Document 2, it is possible to change the arrangement of the electric motor in order to cope with environmental changes such as workpieces and jigs. Since the problem of reducing is not recognized, the arrangement of the transformer cannot be changed, and there is a problem that a plurality of resistance welding guns cannot be arranged closer to each other.

  Further, the X-type gun of Patent Document 2 has a configuration in which a pair of gun arms are both attached to a rotating shaft, and a transformer is fixed to one side of the gun bracket with a screw. In the X-type gun of Patent Document 2 in which both of the pair of gun arms rotate, both of the gun arms rotate around the rotation axis as compared to the X-type gun in which one of the gun arms is fixed and the other rotates. Therefore, there is a problem that the operation becomes unstable.

  In addition, since the X-type gun of Patent Document 2 rotates both of the pair of gun arms, two ounce copper plates having flexibility are necessarily required to connect the transformer and the pair of gun arms. In addition, in the X-type gun of Patent Document 2, a pair of gun arms rotate clockwise and counterclockwise. Since the two ounce copper plates of the X-type gun of Patent Document 2 having such a configuration are both bent following the clockwise rotation and counterclockwise rotation of the pair of gun arms, There is a problem that the load due to the bending operation is large and hinders the smooth movement of the gun.

  The present invention has been made to solve the above-described problems, and a main object of the present invention is to provide a resistance welding gun in which a plurality of resistance welding guns can be disposed close to each other.

  Further, the present invention has been made to solve the above-described problems, and the next object of the present invention is to easily control the spot position where the material to be welded is sandwiched and welded by the electrode attached to the tip of the gun arm. And to provide a resistance welding gun with few failures.

  In order to solve the above-described problems and achieve the object, according to the resistance welding gun according to the present invention, a gun bracket having a rotating shaft and a fixed electrode at one end are attached, A fixed arm fixed to the gun bracket; a movable arm having a movable electrode attached to one end thereof; and pivotally attached to the rotating shaft; the other end of the fixed arm and the other end of the movable arm 2 for a fixed arm that supplies a welding current between the fixed side electrode and the movable side electrode, and a drive unit that drives the fixed side electrode and the movable side electrode in a detachable manner. A power supply unit including a secondary terminal and a movable arm secondary terminal, a stationary arm secondary conductor connecting the stationary arm and the stationary arm secondary terminal, the movable arm and the movable arm secondary terminal 2 for movable arm to connect Comprising a conductor, wherein the secondary conductor movable arm, characterized in that it comprises a flexible conductive section in a space provided inside of the gun bracket.

  Further, in order to solve the above-mentioned problems and achieve the object, the resistance welding gun according to the present invention is characterized in that the drive unit and the power supply unit are connected to the rotating shaft of the gun bracket. It is arrange | positioned at the one side of this gun bracket used as a perpendicular | vertical direction, and it can change arrangement | positioning at the other side of this gun bracket.

  In order to solve the above-described problems and achieve the object, the resistance welding gun according to the present invention is characterized in that the flexible conductive portion is concentrically centered on the rotation axis. It is characterized by being arranged in an arc shape.

  Further, in order to solve the above-described problems and achieve the object, according to the resistance welding gun according to the present invention, the first resistance welding gun includes the drive unit and the power source unit. It was arranged on one side of the gun bracket, and the second resistance welding gun was placed on the other side of the gun bracket so that the two resistance welding guns could be placed close together. It is characterized by.

  According to the present invention, a resistance welding gun capable of simultaneously welding a plurality of adjacent locations is provided.

  In addition, according to the present invention, a resistance welding gun is provided which can easily control a spot position where a material to be welded is sandwiched by an electrode attached to the tip of a gun arm and is welded and has high maintainability.

  Hereinafter, an embodiment (one example) of a resistance welding gun according to the present invention will be described in detail with reference to FIGS. 1 to 5 of the accompanying drawings.

  FIG. 1 is a partial cross-sectional side view of a resistance welding gun 10 of the present invention. FIG. 2 is an external plan view of the resistance welding gun 10. FIG. 3 is a front view of the resistance welding gun 10 taken along the line XX. FIG. 4 is a partial sectional side view showing a state in which the movable arm of the resistance welding gun 10 is opened. FIG. 5 is a diagram showing a proximity state of two resistance welding guns.

  The resistance welding gun 10 according to the present invention includes a gun bracket 12 having a rotating shaft 14, a fixed side electrode 26 attached to one end, a fixed arm 22 fixed to the gun bracket 12, and a movable side electrode 36 at one end. The movable arm 32 attached and pivotally attached to the pivot shaft 14 is installed between the other end of the fixed arm 22 and the other end of the movable arm 32, and the fixed side electrode 26 and the movable side electrode 36. A power source provided with a drive unit 40 that can be detachably connected, a fixed arm secondary terminal 54 that supplies a welding current between the fixed side electrode 26 and the movable side electrode 36, and a movable arm secondary terminal 56 A fixed arm secondary conductor 55 for connecting the portion 52, the fixed arm 22 and the fixed arm secondary terminal 54, and a movable arm secondary conductor 57 for connecting the movable arm 32 and the movable arm secondary terminal 56. And the outline It is Bei.

  The gun bracket 12 is composed of two symmetrical plates 12a and 12b, and these two plates 12a and 12b are arranged so that the side surfaces of the plates are parallel to each other at a predetermined interval. A fixed arm 22 is fixed to one end of the gun bracket 12 with bolts 13a, 13b, and 13c, and a robot arm mounting portion 15 to which the robot arm is mounted is provided on the other end.

  A fixed side electrode 26 is detachably attached to one end of the fixed arm 22 via a fixed arm electrode holder 24, and a fixed arm pin hole 27 to which the driving unit 40 is attached is provided on the other end. . Further, the fixed arm 22 is fixed to one end of the gun bracket 12 by bolts 13a, 13b, 13c between one end and the other end.

  Similarly, a movable side electrode 36 is detachably attached to one end of the movable arm 32 via a movable arm electrode holder 34, and a movable arm pin hole 37 to which the drive unit 40 is attached is provided on the other end. Yes. Further, the movable arm 32 is pivotally attached to the pivot shaft 14 between one end and the other end.

  The drive unit 40 is connected to an electric motor 42 having an electric motor side pulley on the output shaft and a drive unit main body 44 having a ball screw and a ball screw nut inside via a drive transmission unit. It has been configured. The ball screw inside the drive unit main body 44 is provided with a movable arm link 45 for connection to the movable arm pin hole 37 at one end and a ball screw side pulley at the other end. The movable arm link 45 is connected to a ball screw nut that is screwed so as to be movable along the axial direction of the ball screw via a drive sliding portion 46. The drive transmission unit includes a drive transmission box 47, an electric motor side pulley and a ball screw side pulley housed in the drive transmission box 47, and a belt spanned between them. Further, on the extension line of the ball screw shaft, an external position of the drive transmission box 47 paired with one end of the ball screw provided with the movable arm link 45 is connected to the fixed arm pin hole 27. A fixed arm link 49 is provided.

  Moreover, the drive part main body 44 is arrange | positioned between the two plates 12a and 12b arrange | positioned so that a mutual plate side surface may become parallel with a predetermined space | interval. The drive unit main body 44 is constructed between the movable arm pin hole 37 and the fixed arm pin hole 27 by a movable arm link 45 and a fixed arm link 49.

  Further, the electric motor 42 is an outer side of one of the two plates 12a and 12b, which is one side surface of the gun bracket 12 which is in a direction perpendicular to the rotating shaft 14 provided on the gun bracket 12 ( For example, in FIG. 1, it is arrange | positioned on the paper surface back side which becomes the outer side of 12b.

  The electric motor 42 removes the movable arm link 45 and the fixed arm link 49 from the movable arm pin hole 37 and the fixed arm pin hole 27 and attaches the gun bracket 12 from one side to the other side ( For example, in FIG. 1, the electric motor 42 is moved from the back side of the paper surface, which is the outer side of 12 b, to the front side of the paper surface, which is the outer side of 12 a). The arrangement can be changed from one side surface of the gun bracket 12 to the other side surface by a method of re-attachment or the like.

  In addition, the power supply unit 52 is located on the side of the gun bracket 12 that is perpendicular to the rotation shaft 14 of the gun bracket 12 so that the power source 52 is positioned next to the motor 42. It is arranged at a position closer to the rotating shaft 14. In addition, the attachment part which attaches the power supply part 52 to the gun bracket 12 is provided in both the one side and the other side of the gun bracket 12, and the power supply part 52 is arranged from one side of the gun bracket 12 to the other side. Changes are possible.

  Further, a fixed arm secondary terminal 54 and a movable arm secondary terminal 56 are provided at one end of the power supply unit 52 (the front side in FIG. 2). The fixed arm secondary terminal 54 is connected to the fixed arm 22 via the fixed arm secondary conductor 55. As a result, the fixed arm secondary terminal 54 and the fixed side electrode 26 are electrically connected. It will be. The movable arm secondary terminal 56 is connected to the movable arm 32 via the movable arm secondary conductor 57. As a result, the movable arm secondary terminal 56 and the movable side electrode 36 are electrically connected. Will be.

  The movable arm secondary conductor 57 extends from one end of the power supply unit 52 in a direction parallel to the rotary shaft 14, and the other end is formed by two plates 12 a and 12 b constituting the gun bracket 12. The movable arm secondary conductor connecting portion 57a reaching the space, the so-called ounce copper plate 57b as a flexible conductive portion connecting the movable arm secondary conductor connecting portion 57a and the movable arm 32, and the ounce copper plate 57b An ounce copper plate fixing portion 57c fixed to the movable arm 32 is formed. The ounce copper plate 57b is a conductor that can be bent by stacking a plurality of copper plates having a thickness of several millimeters, which is also called a corpel, a shunt, a laminated copper foil, or the like.

  The ounce copper plate 57b is arranged in an arc on a concentric circle centered on the rotation shaft 14 in a space formed by the two plates 12a and 12b constituting the gun bracket 12.

  Further, the space formed by the two plates 12a and 12b constituting the gun bracket 12 is the direction of the fixed side electrode 26 and the movable side electrode 36 to which the material to be welded is resistance-welded (the gun bracket 12 in FIG. 1). It opens in the direction of the left side of the page. Therefore, a spatter cover 16 is provided to protect the ounce copper plate 57b disposed in the space formed by the two plates 12a and 12b from spatter during welding and other foreign matters such as oil and fine dust. It has been.

  In the resistance welding gun 10 of the present invention configured as described above, when the electric motor 42 is rotated from the state shown in FIG. 1, the rotational force of the electric motor 42 is changed from the output shaft to the electric motor side pulley, belt, It is transmitted to the ball screw of the drive unit main body 44 via the ball screw side pulley. The ball screw is rotated by the transmitted rotational force, and the ball screw nut screwed is linearly driven on the ball screw. By this linear drive, the movable arm 32 rotates about the rotation shaft 14 through the drive sliding portion 46 connected to the ball screw nut, the movable arm link 45, and the movable arm pin hole 37. By the rotation of the movable arm 32, the movable electrode 36 is separated from the fixed electrode 26 and is in an open state as shown in FIG.

  In this state, when the resistance welding gun 10 is moved to the workpiece position and the electric motor 42 is rotated in the reverse direction, the movable side electrode 36 approaches the fixed side electrode 26 to be in a pressure operation state in which the workpiece is sandwiched. When the power supply unit 52 is operated in this state, a welding current is supplied between the fixed side electrode 36 and the movable side electrode 26, and the material to be welded is resistance welded.

  The resistance welding gun according to the present invention does not have a transformer, a motor, or the like arranged as protrusions on both sides of the gun bracket as in the gun of Patent Document 1, and as described above, the transformer and the motor on either side. Is arranged. Therefore, as shown in FIG. 5, the first resistance welding gun 10 has an electric motor 42 and a power source 52 arranged on one side of the gun bracket 12, and the second resistance welding gun is placed on the other side of the gun bracket 12. By arranging the electric motor 42 and the power supply unit 52, two resistance welding guns can be arranged close to each other.

  In addition, the two resistance welding guns 10 and 100, the gun bracket 12, the electric motor 42, and the power supply unit 52 that can be arranged close to each other are common parts that do not require the preparation of symmetrical parts. Therefore, a resistance welding gun that can be arranged close to each other at low cost is provided.

  Also, the resistance welding gun of the present invention differs from the gun disclosed in Patent Document 2 and the gun disclosed in Japanese Patent Application Laid-Open No. 2007-268567 in that one of a pair of gun arms is used as a fixed arm. Can be individual. Furthermore, by using one of the gun arms as a fixed arm, the entire pair of gun arms will not rotate clockwise and counterclockwise, causing an unnecessary load on the ounce copper plate. It became possible to prevent.

  Since the movable arm secondary conductor 57 including the ounce copper plate 57b is a connection path of the welding current to the movable arm that rotates, it is likely to be a protrusion on the side surface of the gun bracket 12, and a plurality of resistance welding guns are used. It was easy to become an obstacle for the close placement. In addition, the movable arm secondary conductor 57 including the ounce copper plate 57b has a large number of parts, and the movable arm secondary conductor 57 is changed every time the power supply unit 52 is rearranged between one side surface and the other side surface of the gun bracket 12. The whole thing had to be relocated.

  For this reason, in the resistance welding gun of the present invention, the ounce copper plate 57b is attached to the gun bracket 12 in order to reduce the protrusions on the side surface of the gun bracket 12 and to eliminate the need to relocate the entire movable arm secondary conductor 57. It arrange | positions in the space comprised by the plate 12a and the plate 12b used as an inside. As a result, the resistance welding gun is a compact resistance welding gun that makes it easier to place a plurality of resistance welding guns in close proximity, and the power source 52 can be easily repositioned between one side surface and the other side surface of the gun bracket 12. It became a welding gun.

  In addition, the structure which arrange | positions the ounce copper plate 57b in the space provided in this gun bracket 12 is also disclosed by Unexamined-Japanese-Patent No. 2007-268567 and Unexamined-Japanese-Patent No. 2008-183625, for example. However, these guns are guns for achieving an object different from the object of providing a resistance welding gun in which a plurality of resistance welding guns of the present invention can be arranged close to each other. It is arranged inside the bracket. For this reason, these guns have a gap between the two plates constituting the gun bracket that is wider than the gap between the two plates 12a and 12b of the resistance welding gun 10 of the present invention, and therefore it is difficult to place them close to each other. is there.

  Further, in the resistance welding gun of the present invention, the ounce copper plate 57b is arranged in an arc shape on a concentric circle with the rotation shaft 14 as the center, and the length of the arc is approximately 1/4 to 1/3 of the circumference. Therefore, compared with the ounce copper plate disclosed in Patent Document 2, Japanese Patent Application Laid-Open No. 2007-268567, or Japanese Patent Application Laid-Open No. 2008-183625, the ounce copper plate is more efficient in the gun (the space in which the ounce copper plate is disposed is in the gun bracket). Is arranged without waste). This has the effect of making the entire gun compact in order to provide a resistance welding gun in which a plurality of resistance welding guns, which is the object of the present invention, can be arranged close to each other, and from the shape of the ounce copper plate 57b in FIG. As the shape of the ounce copper plate 57b changes, the entire ounce copper plate bends with respect to the movement of the movable arm 32. Therefore, the ounce copper plate has a smaller amount of deflection and is smoother than the ounce copper plate of Patent Document 2 and the like. There is an effect of extending the life.

  Spattering during welding is also protected by the spatter cover 16, but the resistance welding gun 10 according to the present invention has an interval between the two plates 12a and 12b inside the gun bracket 12 as disclosed in JP-A-2007-268567. Since only the width of the ounce copper plate 57b is compared with the open 2008-183625, there is an effect that it is difficult to be exposed to spatter during welding. In particular, in the resistance welding gun 10 of the present invention, the purpose is to arrange the guns close to each other. Therefore, it is very important not to be sputtered by the adjacent resistance welding gun, and the life of the ounce copper plate 57b Extension is possible.

  Needless to say, the present invention is not limited to the above-described embodiments and can be variously modified without departing from the gist of the present invention. For example, in the resistance welding gun 10 of the present invention, it has been described that the ounce copper plate is disposed at one place inside the gun bracket 12, but it is also possible to use the ounce copper plate for the secondary conductor 55 for the fixed arm. Nor.

The partial cross section side view of the resistance welding gun 10 of this invention. FIG. 3 is an external plan view of the resistance welding gun 10. The XX cross section front view of the resistance welding gun 10. FIG. FIG. 2 is a partial cross-sectional external view showing a state where a movable arm of the resistance welding gun 10 is opened. The figure which shows the proximity | contact state of two resistance welding guns.

Explanation of symbols

10 .. Resistance welding gun, 12 .... Gun bracket, 12a, 12b ... Plate, 13a, 13b, 13c ... Bolt, 14 .... Rotating shaft, 15 .... Robot arm mounting part, 16 .... Spatter cover, 22 .. Fixed arm, 24 .. Electrode holder for fixed arm, 26 .. Fixed side electrode, 27 .. Pin hole for fixed arm, 32 .. Movable arm, 34 .. Electrode holder for movable arm, 36. Side electrode, 37 ..Moveable arm pin hole, 40 ..Drive section, 42 ..Electric motor, 44 ..Drive body, 45 ..Link for movable arm, 46 ..Drive slide section, 47 · · Drive transmission box, 49 · · Link for fixed arm, 52 · · Power supply unit, · · · Secondary terminal for fixed arm, 55 · · Secondary conductor for fixed arm, 56 · · Secondary terminal for movable arm, 57..Secondary for movable arm Body, secondary conductor connection portion 57a · · movable arm, 57 b · · oz copper, 57c · · oz copper plate fixing portion 57c

Claims (4)

A gun bracket with a pivot axis;
A fixed arm attached to one end and fixed to the gun bracket;
A movable arm having a movable electrode attached to one end and pivotally attached to the pivot shaft;
A drive unit that is installed between the other end of the fixed arm and the other end of the movable arm, and that drives the fixed side electrode and the movable side electrode to be detachable;
A power supply unit comprising a fixed arm secondary terminal and a movable arm secondary terminal for supplying a welding current between the fixed side electrode and the movable side electrode;
A fixed arm secondary conductor connecting the fixed arm and the fixed arm secondary terminal;
A movable arm secondary conductor connecting the movable arm and the movable arm secondary terminal;
The movable arm secondary conductor includes a flexible conductive portion in a space provided inside the gun bracket.
The drive unit and the power supply unit are disposed on one side surface of the gun bracket that is perpendicular to the rotation axis of the gun bracket, and can be rearranged on the other side surface of the gun bracket. Resistance welding gun. 2. The resistance welding gun according to claim 1 , wherein the flexible conductive portions are arranged in an arc on a concentric circle with the rotation axis as a center . The first resistance welding gun has the drive unit and the power supply unit arranged on one side of the gun bracket, and the second resistance welding gun has the drive unit and the power supply unit arranged on the other side of the gun bracket. The resistance welding gun according to claim 1, wherein two resistance welding guns can be arranged close to each other . The first resistance welding gun has the drive unit and the power supply unit arranged on one side of the gun bracket, and the second resistance welding gun has the drive unit and the power supply unit arranged on the other side of the gun bracket. The resistance welding gun according to claim 2, wherein two resistance welding guns can be arranged close to each other .

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