JP5226041B2 - Spot welding gun - Google Patents

Description

  The present invention relates to a spot welding gun in which an arm provided with an electrode at an end is attached to a gun body, and more particularly to a spot welding gun provided with a rotating arm.

2. Description of the Related Art Conventionally, portable spot welding guns that weld an object to be welded by manual operation have been widely used in welding work on automobile assembly lines, sheet metal repair of accident vehicles, and the like.
For example, the arm can be easily exchanged, and the electrode tips can be accurately arranged at positions facing each other. The first electrode chip and the second electrode chip facing each other, and the first electrode chip are replaced by the second A resistance welding gun comprising a gun body having a driving means for holding the electrode tip so as to be able to come into contact with and separating from the electrode tip, and an arm that is rotatably and detachably fixed to an arm holder provided in the gun body. The arm holder has a shaft hole that pivotally supports the end of the arm and a direction that is spaced apart from the opening surface on the arm side by a predetermined distance on the inner peripheral surface of the shaft hole and that is orthogonal to the rotation axis direction. And a first groove having a start end and a terminal end formed on the inner peripheral surface of the shaft hole, and a second groove communicating the arm-side opening surface and the first groove. The arm portion holds the second electrode tip on one end side. A rotation shaft provided on the other end of the arm, and an outer peripheral surface of the rotation shaft, and the first and second when the first and second ends of the first groove are brought into contact with each other. A spot welding gun is known which is composed of protrusions that position the arm so that the electrode tips face each other (for example, Patent Document 1).

JP 2004-314131 A

  However, in the structure according to Patent Document 1, the arm that holds the electrode tip can be rotated only 90 degrees on one side. Therefore, depending on the work to be welded, inconvenience occurs in operation, and the work efficiency is affected. There was a fear. Also, positioning is facilitated by bringing the projection of the shaft portion inserted through the arm holder into contact with the groove. However, if a tightening step with a tightening lever is not performed in this state, each other Since it is a structure that cannot be fixed with the electrode tip positions facing each other accurately, the operator must confirm whether or not the tightening has been performed securely with the protrusions in contact with the grooves. The tightening process becomes complicated and the burden on the operator may increase.

  Therefore, the present invention solves such problems, and it is easy to replace the arm, and adopts a simple structure to accurately arrange and fix the electrode tips at positions facing each other. It is an object to provide a spot welding gun that can be used.

  In order to solve the above problem, the spot welding gun according to the first aspect of the present invention includes a first electrode tip and a second electrode tip facing each other, and the first electrode tip and the second electrode tip. In a spot welding gun comprising a gun main body provided with a driving means for holding and separating so as to be able to abut against the arm, and an arm rotatably and detachably fixed to an arm holder provided in the gun main body, A through hole that pivotally supports one end of the arm; and a second electrode chip that is installed at the other end, the position regulating mechanism includes a base portion having the through hole, and a switch that is slidably installed in the through hole. A pin that is installed inside the arm and has a head protruding from the arm end face against the elastic force of the elastic member, and a base portion for holding the arm inserted into the shaft portion of the arm holder. Fastened, The chromatography arm and rotatable in a state in which the pin head is fitted with the through hole of the base portion, and is characterized in that said first and second electrode tips facing each other.

  In addition, a spot welding gun according to a second aspect of the present invention is the spot welding gun according to the first aspect, wherein the spot welding gun includes a tapered portion corresponding to a through hole in the base portion and a head portion in the pin. .

  The spot welding gun according to claim 3 of the present invention is the spot welding gun according to claim 1 or 2, wherein the base of the pin that abuts against the head of the pin in the arm turning state. A guide guide groove is provided so as to secure the through hole from the side surface to the bottom surface.

  Moreover, the spot welding gun of the invention according to claim 4 of the present invention is the spot welding gun according to any one of claims 1 to 3, wherein one end from the end surface is provided along the longitudinal direction of the arm. A slit is provided over the through hole that is pivotally supported, and a tightening lever is provided in a screw hole that is orthogonal to the slit.

  The spot welding gun according to claim 5 of the present invention is the spot welding gun according to any one of claims 1 to 4, wherein the spot welding gun is installed in parallel with the advancing / retreating direction of the first electrode tip. And a rotation restricting member that couples the rod portion to the driving means and fixes the driving means in a state of being rotated with respect to the gun body.

  In the spot welding gun according to claim 1 of the present invention, by pressing the switch and moving it downward, the pin is moved downward against the elastic force of the elastic member, and the fitting with the through hole is released. be able to. As a result, since one end portion of the arm is pivotally supported by the shaft portion, the arm can be rotated in both the clockwise and counterclockwise directions. The work efficiency can be improved without requiring a replacement process. In the rotating state, the first and second electrode chips can be accurately arranged and fixed at positions facing each other by fitting the head of the pin into the through hole of the base portion. The conventional tightening process can be eliminated.

  In the spot welding gun according to claim 2 of the present invention, since the taper portion corresponding to the through hole in the base portion and the head portion of the pin is provided, rattling in fitting can be eliminated. The opposing positions of the first and second electrode chips can be made more reliable.

  In the spot welding gun according to claim 3 of the present invention, the guide guide groove is provided so as to secure the through hole from the side surface to the bottom surface of the base portion in contact with the head portion of the pin in the arm rotating state. Therefore, by rotating the arm, the pin slides along the guide guide groove and moves downward against the elastic force of the elastic member, so that the pin is semi-automatically fitted into the through hole. Since the first and second electrode chips can be accurately arranged and fixed at positions facing each other, the burden on the operator can be eliminated.

  In the spot welding gun according to claim 4 of the present invention, a slit is provided along the longitudinal direction of the arm from the end surface to a through hole that pivotally supports one end, and a tightening lever is provided in a screw hole orthogonal to the slit. By narrowing the width of the slit with the tightening lever, the first and second electrode chips are accurately arranged and fixed at positions facing each other by fitting the pin head and the through hole of the base part. In addition, the arm can be securely fixed to the shaft portion.

  In the spot welding gun according to claim 5 of the present invention, the rod portion installed in parallel with the advancing / retreating direction of the first electrode tip and the driving means are connected, and the driving means is rotated with respect to the gun body. Since the rotation restricting member to be fixed at is provided, the piston rod can be reliably advanced and retracted with the electrode tips facing each other. Thereby, the bent electrode tip can be used depending on the welding location. That is, an electrode tip suitable for the shape of the workpiece can be selected.

It is a front view of the spot welding gun concerning the present invention. It is a partially omitted plan view of a spot welding gun according to the present invention. (A) The perspective view which decomposed | disassembled the position control mechanism of the spot welding gun which concerns on this invention, (b) It is the said PP sectional drawing. (A) A partially omitted enlarged plan view of a spot welding gun according to the present invention, and (b) a QQ sectional view thereof. It is a front view of the spot welding gun of another embodiment concerning the present invention. It is a front view of the spot welding gun concerning the present invention which installed a rotation control member. It is a front view of a rotation control member.

  Hereinafter, a spot welding gun according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the spot welding gun 1 according to the present invention mainly includes a gun body 2 including an air cylinder 2 a and a first electrode tip 3, and a bracket 4 for fixing the arm holder 5 to the gun body 2. The arm 7 includes the second electrode tip 10 that is pivotally supported by the arm holder 5.

  As shown in FIG. 1, the gun body 2 has an air cylinder 2a and a piston rod 2b serving as driving means for moving the first electrode tip 3 to pressurize the work piece, and an arm 7 that can be rotated to the gun body 2. It comprises an arm holder 5 that is detachably fixed, a bracket 4 that connects the arm holder 5 to the gun body 2, and a hanging metal fitting 18 for attaching the spot welding gun 1 to a spot welding apparatus.

  The air cylinder 2a is provided with a piston rod 2b inside, and the piston rod 2b can be moved forward and backward by air pressure. An air hose (not shown) is connected to the air cylinder 2a via an air valve (not shown).

  The piston rod 2b is provided with a first electrode tip 3 at the tip, and when the piston rod 2b is moved by the air pressure by the air cylinder 2a, the first electrode tip 3 presses the workpiece. A first power cable E1 is connected to the piston rod 2b via a first cable joint (not shown), and supplies electricity to the first electrode chip 3.

  The bracket 4 is mainly installed above the gun body 2, holds a second cable joint (not shown) coupled to the arm holder 5, and connects the arm holder 5 to the air cylinder 2a. The second cable joint is connected to a separate second power cable (not shown).

  The arm holder 5 is formed from a column bent in a substantially L shape. As shown in FIGS. 1 and 3, the end portion bent in the vertical direction has a shaft portion 6 having a smaller diameter than the outer shape via a stepped portion. An attachment hole 6b for attaching the base portion 12 is provided on the end surface 6a of the shaft portion 6 so as to be orthogonal to the end surface 6a. By pivotally supporting the arm 7 on the shaft portion 6, as shown in FIG.

  The arm 7 includes a rotating arm 8 and a holding arm 9 and is connected in a substantially L shape. As shown in FIGS. 1 and 3, the rotating arm 8 is formed with a through hole 8 a for inserting the shaft portion 6 at one end. An attachment hole 8b for inserting the pin 14 is formed on the other end side having a predetermined interval from the through hole 8a. In addition, a slit 8c is formed at one end on the side having the through hole 8a from the end surface to the through hole 8a along the longitudinal direction of the rotating arm 8, and in the width direction of the rotating arm, A screw hole 8d for attaching the tightening lever 11 is formed so as to be orthogonal to each other.

  One end of the holding arm 9 is connected to a separate third power cable E2, and the second electrode chip 10 is provided at the other end. As shown in FIG. 2, the tightening lever 11 is provided in the screw hole 8d orthogonal to the slit 8c, and thereby the width of the slit 8c is narrowed, so that the rotating arm in the arm 7 pivotally supported by the shaft portion 6 is provided. 8 can be fixed to the shaft portion 6. Further, since the arm 7 is securely fixed to the shaft portion 6 by a position restricting mechanism 17 which will be described later, the tightening lever 11 is used as an auxiliary, and any end face in the width direction of the rotating arm 8 is used. Can also be installed.

  As shown in FIGS. 1, 3 and 4, the position regulating mechanism 17 that holds the second electrode 10 chip at a position facing the first electrode chip 3 includes a base portion 12, a switch 13, a pin 14, and an elastic member 15. And the locking pin 16.

  The pin 14 has a substantially cylindrical shape, and has a tapered head portion 14a having a smaller diameter than the outer shape at the tip portion and a through long hole 14b on the side surface. The pin 14 is provided with an elastic member 15 such as a spring below, is inserted into the mounting hole 8b of the rotating arm 8, and is inserted into a through hole (not shown) and a through long hole 14b formed on the side surface of the rotating arm 8. It is installed by inserting the locking pin 16. In this state, the taper head portion 14a protrudes from the arm end surface against the elastic force of the elastic member 15, and is movable within the range of the through long hole 14b. The through-hole 14b is formed in a range in which the tapered head portion 14a can move downward from the arm end surface.

  The base part 12 is formed from a substantially rectangular steel sheet. A plurality of through holes 12d corresponding to the attachment holes 6b formed in the end surface 6a of the shaft portion 6 of the arm holder 5 are formed at one end, and a through hole for attaching the switch 13 is formed at the other end. Yes. The through-hole is formed of an insertion portion 12b for inserting the switch 13 and a tapered portion 12c for fitting the pin 14, and the tapered portion 12c has a shape whose diameter is larger than the insertion portion 12b downward. Is done. A flat portion having a larger diameter than the insertion hole 12b is formed at the boundary between the insertion portion 12b and the tapered portion 12c. A guide guide groove 12 a is formed from the side surface to the bottom surface of the base portion 12. The guide guide groove 12a is desirably formed so as to secure the through-hole, but it is only necessary that at least a part of the tapered portion 12c for fitting the pin 14 can be secured. The formation position of the guide guide groove 12a will be described later.

  The switch 13 is formed of, for example, a substantially columnar head portion 13a, a base portion 13b extending downward, and a leg portion 13c. The base portion 13b is inserted into the insertion portion 12b of the base portion 12, the head portion 13a protrudes from the upper surface of the base portion 12, and the leg portion 13c contacts the flat portion at the boundary between the insertion portion 12b and the tapered portion 12c. This prevents it from coming off and is slidably attached to the base portion 12.

  As shown in FIGS. 1 and 4, the base portion 12 having the switch 13 is arranged so that the pivot arm 8 pivotally supported by the shaft portion 6 is held between the lower arm holder 5 and the upper portion. It is attached to the shaft part 6. Since it is fixed only by the shaft 6, the arm 7 can be rotated. When the pin 14 in the rotating arm 8 is fitted into the through hole in the base portion 12, the second electrode chip 10 installed at the tip of the holding arm 9 is held at a position facing the first electrode chip 3. .

  The spot welding gun 1 configured as described above is spot-welded by sandwiching an object to be welded in the gap between the first electrode tip 3 and the second electrode tip 10. More specifically, when the spot welding gun 1 is operated with the arm 7 positioned, compressed air flows into the air cylinder 2 a in the gun body 2. With this compressed air, the piston rod 2b is pushed out of the air cylinder 2a. As the piston rod 2b is pushed out, the first electrode tip 3 held at the tip is brought into contact with the workpiece. The object to be welded is pressed against the second electrode tip 10 on the opposite side, and is sandwiched and pressed between the first electrode tip 3 and the second electrode tip 10. Thereafter, when the applied pressure reaches a predetermined value, spot welding is performed by energizing the first electrode tip 3 and the second electrode tip 10.

  Further, when the workpiece cannot be sandwiched with the second electrode tip 10 held at a position facing the first electrode tip 3 due to the shape of the workpiece, as shown in FIG. Then, the arm 7 is rotated. Specifically, as shown in FIG. 4B, the taper head portion 14a protrudes from the arm end surface by the elastic force of the elastic member 15, and is fitted to the through hole in the base portion 12, that is, the corresponding taper portion 12c. In a state where the electrode tip 3 and the second electrode tip 10 face each other, the switch 13 is pressed from above. Thereby, the pin 14 is pushed down against the elastic force of the elastic member 15 via the leg part 13c contact | abutted with the taper part 14a. Then, the taper head portion 14a is moved downward and the fitting is released, whereby the arm 7 can be rotated around the shaft portion 6. As a result, the gap between the second electrode tip 10 and the gun body 2 is wider than the gap when the first electrode tip 3 and the second electrode tip 10 face each other. Even in the case of having a size, the gap between the second electrode tip 10 and the gun body 2 can be passed.

  After placing the work piece, the arm 7 is rotated to hold the second electrode tip 10 at a position facing the first electrode tip 3. Specifically, the arm 7 is rotated in a direction in which the second electrode 10 faces the first electrode 3. As a result, the pin 14 abuts on the guide guide groove 12 a formed in the base portion 12 on the locus of the pin 14 with the shaft portion 6 as the rotation center. Then, the pin 14 slides along the guide guide groove 12a, the tapered head portion 14a is pressed and moved downward, and is fitted into a through hole in the base portion 12, that is, the corresponding tapered portion 12c. The second electrode chip 10 can be held at a position facing the first electrode chip 3 without rattling. The position regulating mechanism 17 can accurately arrange and fix the first electrode chip 3 and the second electrode chip 10 at positions facing each other. Later, the arm 7 is supplementarily fixed to the shaft portion 6 by the tightening lever 11. Thereby, it can adhere more reliably.

  As described above, according to the spot welding gun 1 according to the embodiment of the present invention described above, since one end portion of the arm 7 is pivotally supported by the shaft portion 6, the arm 7 is rotated clockwise and counterclockwise depending on the shape of the welded portion. Since it can be rotated in any clockwise direction, work efficiency can be improved. In the rotating state, the first electrode chip 3 and the second electrode chip 10 are accurately arranged and fixed at positions facing each other semi-automatically by the position restriction mechanism 17 simply by rotating the arm 7. Therefore, the burden on the operator can be eliminated.

  In this embodiment, the arm 7 is composed of the rotating arm 8 and the holding arm 9, but it may be formed of one arm, and the second electrode chip 10 faces the first electrode chip 3. Any other shape such as a substantially U shape may be used as long as it can be held in position. These can be detached by removing the base portion 12.

  Moreover, although the through-hole in the base part 12 was formed from the insertion part 12b and the taper part 12c, it may be formed only by either one of the insertion hole 12b or the taper part 12c. . In this case, the heads of the pins 14 need only have shapes corresponding to the respective heads. Furthermore, in the guide guide groove 12a, the part which can be fitted with the head part of the pin 14 should just be ensured.

  Furthermore, in the present embodiment, it relates to the so-called C-type spot welding gun 1, but as shown in FIG. 5, a position regulating mechanism 17 can also be adopted for the so-called X-type spot welding gun 1a.

  On the other hand, depending on the installation position of the electrode rod (not shown) attached to the gun body 2, the piston rod 2b may be rotated. The rotation is performed with the advancing / retreating direction of the piston rod 2b as a rotation axis. Further, depending on the shape of the workpiece, an electrode tip having a bent tip may be used.

  When the bent electrode tip is used by rotating the piston rod 2b as described above, the bent electrode tip may not be accurately arranged with respect to the opposing electrode tip.

  Therefore, as shown in FIG. 6, a spot welding gun 1b in which the rotated piston rod 2b is fixed may be used. The spot welding gun 1b is fixed by the rotation restricting member 19 in a state where the piston rod 2b is rotated. Of course, the spot welding gun 1b includes the position regulating mechanism 17.

  The rotation restricting member 19 is preferably formed of an insulating member, and is formed of, for example, duracon. As shown in FIG. 7, the rotation restricting member 19 is formed with an insertion portion 19 a through which the guide portion 20 is inserted at one end portion. The insertion part 19a should just be a shape which can be slid with respect to the rod part 20a of a through-hole, a notch, and the other guide part 20. FIG.

  On the other hand, a through hole 19b through which the piston rod 2b is inserted is formed at the other end. A slit 19c is formed at one end on the side having the through hole 19b from the end portion to the through hole 19b. A screw hole 19d for attaching the tightening lever 11a is formed so as to be orthogonal to the slit 19c.

  The guide part 20 is a member connected to the rotation restricting member 19. The guide part 20 has a rod part 20a formed in a rod shape, for example. The guide part 20 is installed in the arm holder 5 in a state where the rod part 20a is arranged in parallel with the advance / retreat direction of the piston rod 2b.

  The rotation restricting member 19 is installed in a state where the piston rod 2b is rotated with respect to the air cylinder 2a. Specifically, the rod portion 20a of the guide 20 is inserted through the insertion portion 19a, the piston rod 2b is inserted through the through hole 19b, and is fixed to the piston rod 2b by the tightening lever 11a. Thereby, in the state which the piston rod 2b rotated with respect to the air cylinder 2a, the said rotation is controlled and fixed.

  Since the rotation restricting member 19 moves together with the piston rod 2b, it is desirable that the shape of the insertion portion 19a is substantially the same as the outer diameter of the rod portion 20a. The guide portion 20 of the spot welding gun 1b can be connected to the rotation arm 8 or the like as long as the rod portion 20a of at least the portion where the rotation restriction member 19 is installed is disposed in parallel with the advancing / retreating direction of the piston rod 2b. It can also be installed.

  In the spot welding gun 1b configured as described above, the rotation of the piston rod 2b with respect to the air cylinder 2a is fixed. Therefore, the piston rod 2b can be reliably advanced and retracted with the electrode tips facing each other. it can. Thereby, the bent 1st electrode tip 3a can be used depending on a welding location. Also, the corresponding electrode tip can be a bent second electrode tip. As a result, an electrode tip suitable for the shape of the workpiece can be selected.

1, 1a, 1b Spot welding gun 2 Gun body 2a Air cylinder 2b Piston rod 3, 3a First electrode tip 4 Bracket 5 Arm holder 6 Shaft 6a End face 6b Mounting hole 7 Arm 8 Rotating arm 8a Through hole 8b Mounting hole 8c Slit 8d Screw hole 9 Holding arm 10 Second electrode tip 11, 11a Tightening lever 12 Base portion 12a Guide guide groove 12b Insertion portion 12c Taper portion 12d Through hole 13 Switch 13a Head portion 13b Base portion 13c Leg portion 14 Pin 14a Taper head Part 14b Through long hole 15 Elastic member 16 Locking pin 17 Position restricting mechanism 18 Hanging bracket 19 Rotation restricting member 19a Insertion part 19b Through hole 19c Slit 19d Screw hole 20 Guide part 20a Rod part

Claims (5)

A first electrode chip and a second electrode chip facing each other;
A gun body comprising driving means for holding the first electrode tip so as to contact and separate from the second electrode tip;
In a spot welding gun comprising an arm that is pivotably and detachably fixed to an arm holder provided in a gun body,
The arm has a through hole that pivotally supports one end of the arm;
A second electrode tip installed at the other end,
The position restricting mechanism includes a base portion having a through hole, a switch that is slidably installed in the through hole, a pin that is installed inside the arm and has a head protruding from the arm end surface against the elastic force of the elastic member, With
The base portion is fixed to the shaft portion so as to sandwich the arm inserted into the shaft portion of the arm holder, and the arm can be rotated.
A spot welding gun, wherein the first and second electrode tips face each other in a state in which a head portion of a pin is fitted in the through hole of the base portion.   The spot welding gun according to claim 1, further comprising a tapered portion corresponding to each of the through hole in the base portion and the head portion of the pin.   3. The spot welding gun according to claim 1, wherein a guide guide groove is provided so as to secure the through hole from a side surface to a bottom surface of the base portion in contact with the head portion of the pin in the arm rotation state.   The slit according to any one of claims 1 to 3, wherein a slit is provided along the longitudinal direction of the arm from the end surface to a through hole that pivotally supports one end, and a screw lever that is orthogonal to the slit is provided with a tightening lever. Spot welding gun.   A rod restricting member that connects a rod portion installed in parallel with the advancing / retreating direction of the first electrode tip and a driving unit and fixes the driving unit in a state of rotating with respect to the gun body is provided. Item 5. The spot welding gun according to any one of items 4 to 4.

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