JP6033203B2 - Thermal processing torch using electrode rod - Google Patents

Description

  The present invention relates to a thermal processing torch that generates an electric arc using an electrode rod, such as a plasma torch or a TIG torch, and performs welding, cutting, heating, etc. In particular, an electrode rod automatic attachment / detachment mechanism for automatically replacing an electrode rod The present invention relates to a thermal processing torch comprising:

  For example, in a plasma torch in which a rod-shaped tungsten electrode is passed through a cylindrical nozzle base and a nozzle tip is attached to the lower end of the nozzle base, plasma gas supplied to the space of the nozzle base through which the tungsten electrode passes is applied to the tip of the tungsten electrode. The plasma ionized by the generated arc is ejected from the nozzle (air nozzle) of the nozzle tip, and the shield gas supplied to the space between the outer peripheral surface of the nozzle base and the shield cap is moved forward along the outer surface of the nozzle tip. Inject to (material to be processed).

  Although the rod-like tungsten electrode is expressed as a non-consumable electrode rod or simply a non-consumable electrode, the tip gradually wears out (wears or deforms) as the working time of the work such as welding is increased. The non-consumable electrode rod is replaced with an unused product (new article) before it is consumed to the extent that the welding quality is impaired. Various automatic attachment / detachment mechanisms have been proposed to automate replacement work.

    The welding torch described in Patent Document 1 is a collet chuck in which a collet chuck is clamped with an electrode rod guide (hollow rod) connected to a protruding rod of an air cylinder to hold the electrode rod, and the rod is pulled into the air cylinder. Is released, the electrode holding is released, and the electrode rod is discharged by its own weight.

  The TIG welding torch described in Patent Document 2 holds / releases an electrode rod by a chuck (collet) by pushing down / pulling up a hollow rod by a protruding rod of an air cylinder. Also, a new electrode is inserted into the chuck (collet) from the electrode holder at the top of the torch, and the used electrode is ejected from the tip of the torch.

  In the welding torch described in Patent Document 3, an electrode is held by pressing a collet connected to a rod of an air cylinder against the collet body, and when the air cylinder is opened, the collet has a slit provided at a lower portion. It moves to the upper part of the collet body by the elastic force to return to the interval, the slit is opened, the electrode holding is released, and the electrode is discharged by its own weight.

  The automatic electrode changing apparatus described in the cited document 4 takes out an electrode from the torch with an electrode discharge chuck, and sets a new electrode at another location.

Japanese Patent Laid-Open No. 05-285654 JP-A-10-006014 JP 2001-078661 A JP 2008-018443 A

In either torch, when the chuck or hollow rod is pushed down, the outer tapered surface of the tip with the split grooves distributed in the cross of the chuck is driven downward along the inner tapered surface of the chuck stop, and the center The tip part is squeezed in the direction toward the axis to hold the electrode rod, and by pulling up the chuck or the hollow rod, the outer taper surface is driven upward, the squeezing of the tip part is released and the electrode rod is released. Structure.
However, in this structure, the opening of the electrode rod relies only on the elastic force that the chuck tip with the split groove tries to return to its original state, but the elastic force weakens with repeated use and the chuck tip spreads out sufficiently. The electrode cannot be discharged.
Further, Patent Document 2 describes a method of discharging a used electrode by providing an electrode holder on the top of the torch and inserting a new electrode. However, this complicates the structure of the torch. Patent Document 4 describes an automatic electrode exchange device provided with a separate electrode discharge chuck. However, the plasma welding torch in which the electrode is installed in the back of the nozzle cannot grip the electrode. was there.

  An object of the present invention is to stabilize electrode rod gripping and discharging by an electrode rod automatic attaching / detaching mechanism and to improve reliability.

(1) There is a small-diameter hole at the tip, the inner tapered surface (10t) continues to the small-diameter hole, and a large-diameter hole continues to the inner tapered surface, which can be enlarged / reduced in the radial direction at the tip. When the electrode rod (11) does not pass, the small-diameter hole has a diameter smaller than the diameter of the electrode rod, and when the electrode rod passes, the enlarged electrode rod is inserted through the tip. Cylindrical chuck (10) gripped by the part;
A torch that is inserted into the large-diameter hole of the chuck (10) and whose tip is opposed to the inner taper surface (10t), and the tip of the chuck is enlarged / reduced by the axial movement of the chuck (10). A chuck stopper (21) secured to the substrate; and
The chuck (10), the inner taper surface (10t) is separated from the tip of the chuck stopper (21) and the tip of the chuck grips the electrode rod (11); Chuck driving means (22-30) for driving to an electrode bar release position in which the tapered surface (10t) abuts on the tip of the chuck stopper (21) and the tip of the chuck releases the electrode bar (11);
A thermal processing torch (Tch) using an electrode rod, characterized by comprising:

  In addition, in order to make an understanding easy, the code | symbol of the corresponding element or the equivalent element of the Example which is shown in drawing and mentions later in parentheses is attached for reference by reference. The same applies to the following.

  The small hole at the tip of the chuck (10) has a diameter smaller than the diameter of the electrode rod when the electrode rod (11) does not pass, and expands when the electrode rod passes. The tip end grips the electrode rod which is in contact with the tapered surface inside the tip of the holder (9) and the tip of the chuck (10) is pressed and inserted.

  Even when an air cylinder is used as the chuck drive means (22-30) and the power to the welding equipment is turned off when the torch is not used, according to the thermal processing torch (Tch) of the present invention, the inner taper of the chuck is maintained at the electrode rod holding position. Since the surface (10t) is separated from the tip of the chuck stopper (21) and the tip of the chuck grips the electrode rod (11) by elasticity, the clamping force with which the chuck (10) grips the electrode rod (11) varies. The stability and reliability of holding the electrode rod is high.

  Also, when the chuck (10) is driven in the rear end direction, the split piece of the split groove at the tip is surely spread out by the tip taper (21p) of the chuck stopper (21). It can be removed reliably.

It is a block diagram showing the outline of one form of automatic welding equipment using plasma torch Tch which is the heat processing torch of one example of the present invention. FIG. 2 is an enlarged view of the plasma torch Tch shown in FIG. 1, and a part thereof shows a longitudinal section in an electrode bar chuck state. FIG. 2 is an enlarged vertical sectional view of a part of the plasma torch Tch shown in FIG. 1 and shows an electrode bar released state. It is a longitudinal cross-sectional view which shows the electrode rod automatic attachment / detachment mechanism of plasma torch Tch shown in FIG. 1, (a) shows the electrode rod chuck | zipper state which put the chuck | zipper 10 in the electrode rod holding position, (b) is an electrode rod release position. The electrode bar released state is shown. In any state, the chuck stopper 21 is fixed and the position does not change. 2 shows a part of the parts of the plasma torch Tch shown in FIG. 2, (a1) is an enlarged longitudinal sectional view of the chuck 10, (a2) is an enlarged plan view of the chuck 10, and (a3) is a left side surface of the tip portion of the chuck 10. FIG. (B1) is an enlarged vertical sectional view of the chuck stopper 21, and (b2) is an enlarged plan view of the chuck stopper 21. (C1) is an enlarged vertical sectional view of the heat insulation collar 16, and (b2) is a right side view of the heat insulation collar 16. 2 shows a part of other parts of the plasma torch Tch shown in FIG. 2, (a1) is an enlarged vertical sectional view of the connecting rod 23, (a2) is an enlarged plan view of the connecting rod 23, and (a3) is an illustration of the connecting rod 23. It is a right view. (B1) is an enlarged vertical sectional view of the hook half body 26a, (b2) is an enlarged plan view of the hook half body 26a, and (b3) is a right side view of the hook half body 26a. (C1) is an enlarged longitudinal sectional view of the hook half body 26b, (c2) is an enlarged plan view of the hook half body 26b, and (c3) is a right side view of the hook half body 26b. (A1) is an enlarged vertical sectional view of the connecting frame 27, (a2) is an enlarged plan view of the connecting frame 27, and (a3) is a right side view of the connecting frame 27.

  (2) There is a guide groove (10g) extending in the axial direction on the peripheral wall of the large-diameter hole of the chuck (10), and the chuck stopper (21) projects the guide groove (10g) from the inside to the outside. The thermal processing torch using an electrode rod according to (1) above, wherein there is a chuck guide (21 g) fixed to the torch base (1).

  (3) The chuck driving means (22-30) includes an air cylinder (30) for driving the chuck (10) from the electrode rod holding position to the electrode rod releasing position and vice versa. Or the heat processing torch using an electrode bar as described in (2).

  (4) The chuck driving means (22-30) further includes a coil spring (24) interposed between the chuck (10) and a protruding rod (29) of the air cylinder (30). (1) The thermal processing torch using an electrode rod according to any one of (3).

  Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

  The automatic welding equipment shown in FIG. 1 is a plasma torch Tch which is an embodiment of the thermal processing torch of the present invention mounted on an automatic welding robot Wro, and automatically welds a welding target location (not shown). When the predetermined electrode rod replacement timing is reached, the automatic welding robot Wro positions the torch Tch immediately above the electrode rod collection box Ruc, and the torch Tch chuck 10 (FIG. 4) is in the electrode release position (FIGS. 3 and 4). (B)), the tungsten electrode 11 serving as an electrode rod is detached from the torch Tch and falls into the electrode rod collection box Ruc. Next, the torch Tch is lowered from right above one tungsten electrode in the tungsten electrode group prepared on the electrode rod table Ros so as to receive the tungsten electrode into the torch nozzle 15 (FIG. 2). The drive to lower the torch is stopped at the timing when the electrode enters the predetermined position deep inside the torch. An air cylinder on the electrode rod table Ros that supports the tungsten electrode drives the tungsten electrode upward and stops at a predetermined position when the torch is used, where the chuck 10 of the torch Tch is positioned at the electrode chuck position (see FIGS. 2 and 4). The tungsten electrode is held by being driven by (a)). The welding robot Tch resumes the welding operation.

  FIG. 2 is an enlarged view of the plasma torch Tch shown in FIG. A cathode base 2, an insulating bush 3 and an anode base 4 are inserted into the cylindrical inner space of the plasma torch base 1, and these are integrally fixed to the base 1. A nozzle table inner cylinder 5 and a nozzle table 6 are inserted into the anode table 4. A nozzle tip 14 is attached to the lower end (tip) of the nozzle base 6. A connecting cylinder 7 is fixed to the nozzle base 6, and a shield cap 8 with a female thread that accepts the male thread is screwed into the connecting cylinder 7, and the shield cap 8 is rotated in the screwing direction, thereby shielding the shield cap. The end face 8 is fastened to the end face of the base 1.

  There is an electrode holder 9 inside the nozzle base inner cylinder 5 and a conductive chuck 10 inside. A tungsten electrode 11 which is an electrode rod passes through the chuck 10. The tip of the chuck 10 where the split groove 10t is cut is squeezed in a direction toward the center of the tungsten electrode 11 to grip (hold) the tungsten electrode 11. The tungsten electrode 11 passes through the centering stone 13 and is positioned at the center of the nozzle 15 of the nozzle tip 14.

  An electrode holder 9 and a chuck 10 are inserted in the cathode base 2, and the tungsten electrode 11 is electrically connected to a pilot power source and a main power source via the chuck 10, the electrode holder 9 and the cathode base 2.

  Plasma gas is supplied from the plasma gas tube 17 on the arm of the substrate 1 to the inner space of the electrode holder 9, reaches the center hole space of the centering stone 13, and is ionized by an arc at the tip of the tungsten electrode 11 to become plasma. , And ejected from the nozzle 15. The shield gas fed between the nozzle base 6 and the substrate 1 from the shield gas pipe 18 on the arm of the substrate 1 passes through the vent hole of the connecting cylinder 7 and reaches the inner space of the shield cap 8. Erupts forward from the torch.

  The anode pipe 19, which is a conductive water supply pipe, is connected to the anode base 4 through the arm of the base 1, that is, is electrically connected, and the cooling water (solid arrow) supplied to the anode pipe 19 is the anode base. 4 and through the water supply path w1 between the nozzle base 6 and the nozzle base inner cylinder 5, through the ring-shaped space w2 that goes around the nozzle tip mounting portion, and further through the drainage path w3, the insulating bush 3 It passes through the ring-shaped space w4 that is the inner space and exits to the cathode pipe 20 that is a conductive drainage pipe. The cathode pipe 20 is connected to the cathode table 2 through the arm of the base 1. That is, they are electrically connected.

  A cylindrical space is vertically divided into two semi-cylindrical spaces w1 and w3 by a protrusion (not shown) of the nozzle base inner cylinder 5 protruding in the radial direction x and extending in the axial direction z. The space is the water supply channel w1, and the other semi-cylindrical space is the drainage channel w3. The nozzle base 6 has a double-cylindrical shape composed of an outer cylinder (6) having a truncated conical shape and a cylindrical inner cylinder 5. A nozzle tip 14 is inserted into the tip of the inner cylinder 5 of the nozzle base 6. Inside the nozzle base inner cylinder 5 is a centering stone 13 for positioning the tungsten electrode 11 on the axis of the torch base 1.

  The chuck 10 is inside the electrode table 9 and is movable in the axial direction (direction in which the tungsten electrode 11 extends). As shown in (a1) and (a2) of FIG. 5, the tip of the chuck 10 has split grooves 10h distributed in a cross shape, and the diameter of the small-diameter hole through which the tungsten rod 11 passes is smaller than the diameter of the tungsten rod 11. small. However, when the split groove 10h is widened, the diameter of the small-diameter hole is widened, and a tungsten rod can be passed therethrough. The inner tapered surface 10t is continuous with the small diameter hole through which the tungsten rod 11 passes, and the large diameter hole is continuous with the inner tapered surface 10t.

  As shown in FIG. 2, a chuck stopper 21 is inserted into the large-diameter hole of the chuck 10 from its rear end, and a chuck guide 21 g (FIG. 5) of the chuck stopper 21 is attached to the cathode base 2 integrated with the torch base 1. The chuck stopper 21 is fixed to the cathode base 2 (torch base 1) by tightening the electrode holder 9 with the heat-insulating collar 16 that is screwed (fixed). That is, the chuck stopper 21 is fixed to the torch base 1 and does not move. The front end surface of the chuck stopper 21 is a front end taper 21p that faces the inner tapered surface 10t of the chuck 10 and abuts on it. When the chuck 10 moves in the rear end direction and the inner tapered surface 10t comes into contact with the tip taper 21p (FIG. 3), the divided pieces between the dividing grooves 10h are spread outward, that is, a small-diameter hole through which the tungsten rod 11 passes. Since it spreads, the tungsten rod 11 is not gripped. That is, the chuck is released, and the tungsten rod 11 is detached from the chuck 10 and slides down. As shown in FIGS. 5 (a1) and 5 (a2), the chuck 10 has a guide groove 10g at the rear end portion, and a chuck guide 21g at the rear end portion of the chuck stopper 21 is fitted therein (see FIG. 5). 2) Even if the chuck stopper 21 is fixed to the torch base 1 (cathode base 2), the chuck 10 can move in the axial direction.

  A heat insulating collar 16 is fixed to the cathode base 2 by screwing. The rear end of the chuck 10 is inside the heat insulating collar 16 (FIG. 4A) and is inserted into the front end of the shield collar 22. Further, the tip of the connecting rod 23 ((a1)-(a3) in FIG. 6) is connected to the rear end of the chuck 10 by screwing into the female screw hole 10f ((a1) in FIG. 5) ( Figure 2). The connecting rod 23 passes through the coil spring 24 and the engagement ring 25. The front end of the coil spring 24 abuts on the rear end surface of the shield collar 22, and the rear end faces the engagement ring 25.

  The tip of the connection frame 27 (FIG. 7) is fixed to the heat insulating collar 16 (FIG. 5 (c1), (c2)) fixed to the cathode base 2 integral with the torch base 1 with four screws. Has been. An air cylinder 30 is attached to the rear end of the connecting frame 27 (FIG. 2). The engagement ring 25 is gripped by the tip end portions of the two split hook halves 26a and 26b ((b1)-(b3), (c1)-(c3) in FIG. 6), and from the air cylinder 30 at the rear end portion. By grasping the connecting collar 28 fixed to the protruding protruding rod 29 and connecting the halves 26a and 26b together with screws, the protruding rod 29 is connected to the engagement ring 25 (FIG. 2).

  FIG. 2 shows an electrode bar chuck state in which the protrusion rod 29 of the air cylinder 30 is protruded and the chuck 10 is driven to the electrode bar chuck position via the coil spring 24 and the shield collar 22. FIG. 3 shows the electrode rod released state in which the protruding rod 29 of the air cylinder 30 is pulled in to release the holding of the tungsten rod 11 by the chuck 10.

  4A and 4B, only the automatic attachment / detachment mechanism in the electrode bar chuck state and the electrode bar released state is extracted and shown for easy understanding. In the electrode chuck state shown in FIG. 4A, the tip outer taper of the chuck 10 abuts the inner taper of the electrode holder 9, the split groove portion of the tip is squeezed, and the tungsten rod 11 is gripped. However, as shown in FIG. 4B, when the chuck 10 is driven in the rear end direction and the inner tapered surface 10t abuts on the front end taper 21p of the chuck stopper 21, and further driven in the rear end direction, the chuck 10 Since the split piece between the split grooves at the tip portion of 10 is expanded by the tip taper 21p, the tungsten rod 11 is released and falls downward.

  By pushing out the protruding rod 29 by the distance De by the air cylinder 30, the plasma torch Tch is brought into the electrode bar chuck state shown in FIG. 2 and FIG. Even if the driving pressure of the air cylinder 30 is released in this state for a long time, the chuck 10 does not move so as to hit the tip taper 21p and the tip portion is pushed and the holding of the tungsten rod 11 by the chuck 10 continues. To do.

Tch: Plasma torch Wro: Welding robot Wpw: Welding power source, etc. Ruc: Used electrode bar collection box Ros: Electrode bar table 1: Base body 2: Cathode base 3: Insulating bush 4: Anode base 5: Nozzle base inner cylinder 6: Nozzle Table 7: Connecting cylinder 8: Shield cap 9: Electrode holder 10: Chuck 10h: Split groove 10t: Inner taper 10g: Guide groove 10f: Female screw hole 11: Tungsten electrode 13: Centering stone 14: Nozzle tip 15: Nozzle 16: Thermal insulation Collar 16c: Ring groove 17: Plasma gas pipe 18: Shield gas pipe 19: Anode pipe (water supply pipe)
20: Cathode pipe (drain pipe)
21: chuck stopper 21p: tip taper 21g: slider 22: shield collar 23: connecting rod 23m: male screw 23g: electrode rod receiving hole 24: coil spring 25: engagement ring 26a: hook half body 26ab: connecting groove 26af: threading Hole 26b: Hook half body 26bb: Connection groove 26bf: Female screw hole 27: Connection frame 28: Connection collar 29: Extrusion rod 30: Air cylinder w1: Water supply path w2: Ring-shaped space w3: Drainage path w4: Ring-shaped space

Claims (4)

There is a small-diameter hole at the tip, the inner tapered surface is continuous with the small-diameter hole, and the large-diameter hole is continuous with the inner tapered surface, and there is a split groove at the tip that can be expanded / reduced in the radial direction. The small-diameter hole has a diameter smaller than the diameter of the electrode rod when the electrode rod does not pass, and expands when the electrode rod passes, and a cylindrical chuck in which the tip end grips the inserted electrode rod;
A chuck stopper fixed to a torch base, which is inserted into the large-diameter hole of the chuck and whose tip is opposed to the inner tapered surface and enlarges / reduces the tip of the chuck by the axial movement of the chuck; ,
The chuck is configured such that the inner taper surface is separated from the tip of the chuck stopper and the tip of the chuck grips the electrode rod, and the inner taper surface abuts the tip of the chuck stopper. Chuck driving means for driving the tip portion to an electrode rod release position for releasing the electrode rod;
A heat processing torch characterized by comprising:   2. A guide groove extending in an axial direction is provided on a peripheral wall of the large-diameter hole of the chuck, and the chuck stopper has a chuck guide that protrudes from the inner side to the outer side and is fixed to a torch base. The heat-processing torch described in 1.   The thermal processing torch according to claim 1 or 2, wherein the chuck driving means includes an air cylinder that drives the chuck from the electrode rod holding position to the electrode rod release position and vice versa.   The thermal processing torch according to any one of claims 1 to 3, wherein the chuck driving means further includes a coil spring interposed between the chuck and a protruding rod of the air cylinder.

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