JPH05220576A - Nozzle angle variable type welding torch - Google Patents

Abstract

PURPOSE:To carry out angle displacement of a shielding gas nozzle with respect to the axial center when it comes into contact with fixed material to carry out relief and to prevent breakdown and malfunction of equipment material by arranging a spherical joint and an elastic member on a joining part between a torch main body and the nozzle. CONSTITUTION:A fixed side member 3a of the spherical joint 3 is fitted and fixed on the tip 1a of the torch main body 1 and in the same way, a movable side member 3b is screwed and fixed into the base end part inside of the nozzle 2. In addition, the elastic member 4 (waveform ring made of spring material, for instance) is fitted idly on the tip 1a of the torch main body 1 and the elastic pressure is worked between the stepped shoulder surface 1b of the torch main body and the base end part end face 2a of the nozzle 2. Consequently, the nozzle 2 is tiltable and besides, returned and energized for the axial center of the torch main body 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable nozzle angle welding torch in which the nozzle angle with respect to the axis of the torch body can be freely changed.

[0002]

2. Description of the Related Art The MIG welding method feeds a consumable electrode wire from a wire passage of a torch body, feeds it with an electrode tip at the tip of the torch body, and uses an arc generated between the wire and the base material to melt a molten pool. In order to obtain good quality weld metal, the tip of the torch body is surrounded by a cylindrical nozzle, and a shield gas such as argon is supplied from the gas passage of the torch body to the inside of the nozzle. To protect the weld from the surrounding atmosphere. In order to evenly distribute the shielding gas with a required and sufficient density in a space area of a certain size centered on the electrode wire, the nozzle has a tip diameter set to a certain value or more, and the shaft core is aligned with the shaft core of the torch body. Are arranged.

In this way, the nozzle, which is concentrically arranged so as to project to the outside of the electrode wire with a large diameter, has a margin space left around the welding torch in a narrow groove such as a column-beam joint of a building. Since the nozzle is narrowed, the nozzle easily comes into contact with a fixed object such as a pillar or a wall during the weaving operation.

When a nozzle made of a hard material such as metal or ceramics and integrally fixed to the torch body hits a fixed object, a pressure signal for activating an emergency stop circuit for ensuring safety is detected and automatic welding is performed. Operation of the machine may be stopped unintentionally, causing malfunction. Also, the impact force due to the contact between the nozzle and the fixed object acts on the welding torch or the welding machine body as a destructive force, and the welding work is interrupted each time for repairing or replacing the damaged welding torch. Became.

In order to prevent breakage, malfunction and welding interruption, it has been proposed to use a flexible cloth nozzle.
This nozzle starts to deform when pressed against a fixed object, and increases the amount of deformation as it approaches the fixed object to absorb the impact force due to the contact between the nozzle and the fixed object. In reality, when overheated or spatter adheres, the recoverability is greatly reduced or lost, the original cylindrical shape is restored and the axis does not return to the normal position that matches the axis of the torch body. There was a flaw.

Further, in order to increase the freedom of movement of the welding torch in a narrow space, it has been proposed to make the tip of the nozzle extremely thin. However, with a small diameter nozzle, the area that can be shielded by the shielding gas is narrow, and there is a risk of shield failure, and it may not be possible to sufficiently cover the molten pool depending on the welding speed. There is a problem in doing it.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to accurately absorb the impact force caused by the contact between a nozzle and a fixed object, which causes damage or malfunction of the welding torch or welding machine, or interruption of welding. Nozzle angle variable welding torch that can efficiently perform high quality welding.

[0008]

In the welding torch of the present invention, the nozzle 2 is rotatably connected to the torch body 1 by means of a spherical joint 3, and the nozzle 2 is described below. From the escape position where the axis of the nozzle is angularly displaced with respect to the axis of the torch body 1, the axis of the nozzle 2 becomes the torch body 1.
An elastic member 4 is provided between the nozzle 2 and the torch body 1 for urging the nozzle 2 to return toward a normal position that coincides with the axis of the.

[0009]

When this welding torch is mounted on an automatic welding machine and is applied to the groove 5 having a narrow column-beam joint as shown in FIG. 2, the nozzle is moved by an error in the movement control of the welding torch during the weaving operation. When the tip end of 2 contacts the fixed object, that is, the side wall surface 6a of the column 6 or the end wall surface 7a of the beam 7, the nozzle 2 smoothly rotates about the spherical joint 3, and as shown in FIG. The shaft center of 2 comes to the escape position where the shaft center of the torch body 1 is angularly displaced.

In the process of this escape rotation, the impact force due to the contact between the nozzle 2 and the fixed object is the nozzle 2 and the torch body 1.
Since the elastic member 4 is elastically deformed between them and is accurately absorbed, it does not act as a destructive force on the welding torch or the welding machine body. Further, since the pressure signal for activating the emergency stop circuit of the automatic welding machine is not detected, there is no malfunction of the automatic welding machine or interruption of operation.

When the nozzle 2 moves away from the fixed object by moving the welding torch to a predetermined target position in accordance with the operation program of the automatic welding machine, the pressing force from the fixed object acting through the nozzle 2 disappears. The elastic member 4 recovers its original shape by its inherent elasticity. Therefore, the nozzle 2 urged by the elastic member 4 is returned and rotated about the spherical joint 3, and as shown in FIG. 2, the nozzle 2 is at the normal position where the axis of the nozzle 2 coincides with the axis of the torch body 1. Return immediately.

[0012]

In the illustrated embodiment, a cylindrical gas discharge tip 8 is fitted and fixed to the outer surface of the round bar-shaped tip portion 1a of the torch body 1, and the gas discharge tip 8 has a gas passage 9 formed therein. The outlet end of is open. A round rod-shaped feed tip 10 is screwed and fixed to the end surface of the tip portion 1a of the torch body 1, and an electrode wire 13 fed from a wire passage 12 is inserted into a central hole 11 of the feed tip 10. ing. The fixed side member 3a of the spherical joint 3 is located at a position closer to the base end than the gas discharge tip 8 and is at the tip 1 of the torch body 1.
The movable side member 3a of the spherical joint 3 is screwed and fixed to the base end portion of the right cylindrical nozzle 2.

At the base of the tip 1a of the torch body 1,
Step shoulder surface 1b enlarged to match the outer diameter of the nozzle 2
Has been formed. The elastic member 4 is composed of a corrugated ring plate made of a spring material, and a plurality of corrugations are continuously formed in the circumferential direction. The elastic member 4, which is loosely fitted to the tip portion 1a of the torch body 1, has a wave-shaped corrugated portion 4 on the end surface 2a of the base end portion of the nozzle 2 and the step shoulder surface 1a of the torch body 1.
a and the wave bottom portion 4b are in pressure contact with each other. When the nozzle 2 comes into contact with a fixed object and rotates to an escape position where it is angularly displaced with respect to the axis of the torch body 1, the elastic member 4 is pushed by the end surface 2a of the nozzle 2 and elastically deforms in the direction in which the waveform is crushed. To do.

The elastic member 4 is not limited to the one shown in the figure, and various forms can be adopted. For example, the elastic member is composed of a tubular mesh knitted with a spring material, and one end of the tubular mesh is fitted and fixed to the base end portion of the nozzle with the axial center aligned with the axial center of the nozzle. The other end of the mesh may be fitted and fixed to the receiving portion of the torch body with the axis aligned with the axis of the torch body.

Further, the elastic member is constituted by a coil spring having a large diameter, and one end of the coil spring is fitted and fixed to the base end of the nozzle with its axis aligned with the axis of the nozzle, and the other end of the coil spring. The part may be fitted and fixed to the receiving part of the torch body with the axis of the part aligned with the axis of the torch body.

The elastic member is composed of a plurality of linear spring wires, and a plurality of vertical grooves are provided at equal intervals corresponding to the outer surface of the base end portion of the nozzle and the outer surface of the receiving portion of the torch body. It is also possible to fix each end of the spring wire inserted in the groove to the base end of the nozzle and the receiving part of the torch body with a tightening band or the like.

[0017]

As described above, in the welding torch of the present invention, the nozzle 2 is rotatably connected to the torch body 1 by the spherical joint 3, and the nozzle 2 is biased to return between the nozzle 2 and the torch body 1. The elastic member 4 is provided, and when the nozzle 2 comes into contact with a fixed object, the nozzle 2 smoothly rotates to an escape position in which the axis of the nozzle 2 is angularly displaced with respect to the axis of the torch body 1, and the nozzle 2 and the fixed object are rotated. Since the impact force due to the contact is accurately absorbed by the elastic deformation of the elastic member 4, the welding torch or the welding machine main body is not damaged or malfunctions, or the welding is not interrupted.

In the welding torch of the present invention, it is not necessary to make the tip diameter of the nozzle excessively small in order to increase the degree of freedom of movement in the narrow space, and the tip diameter of the nozzle 2 is set to a necessary and sufficient size. In addition, since the nozzle 2 is always guided and held at the regular position where the axis of the nozzle 2 coincides with the axis of the torch body by the urging of the elastic member 4, the nozzle 2 has a required area around the electrode wire 13. Since the shield space is appropriately formed and maintained, and the entire molten pool can be effectively shielded from the atmosphere, high-quality welding can be efficiently performed.

[Brief description of drawings]

FIG. 1 is a front view showing a longitudinal section of a main part of a variable nozzle angle welding torch according to an embodiment of the present invention.

FIG. 2 is a front view of the welding torch showing a state in which a nozzle is held at a regular position that coincides with an axis of a torch body.

FIG. 3 is a front view of the welding torch showing a state in which the nozzle is rotated to an escape position due to contact with a fixed object.

[Explanation of symbols]

 1 Torch main body 1a Tip part of the torch main body 1b Stepped shoulder surface of the torch main body 2 Nozzle 2a Nozzle end surface 3 Weld joint 3a Fixed side member 3b Movable side member 4 Elastic member 4a Wave head 4b Wave bottom 5 Column 6 Column 6a Column Side wall surface 7 Beam 7a Beam end wall surface 8 Gas discharge tip 9 Gas passage 10 Power supply tip 11 Central hole 12 Wire passage 13 Electrode wire

Claims (1)

[Claims] 1. A nozzle is rotatably connected to a torch body by a spherical joint, and the axis of the nozzle is located at an escape position where the axis of the nozzle is angularly displaced with respect to the axis of the torch body. A variable nozzle angle welding torch in which an elastic member for urging the nozzle to return toward a regular position corresponding to is provided between the nozzle and the torch body.