JPH022556Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas-shielded arc welding torch, and particularly to a nozzle mounting structure suitable for applications such as welding robots that require automatic replacement of the gas nozzle.

Gas shielded arc welding torches require replacing the gas nozzle to remove spatter, etc.
Automatic welding machines such as welding robots, where it is difficult for people to get close to the torch, must be able to automatically replace the gas nozzle.

The nozzle mounting structure of a conventional arc welding torch is shown in FIGS. 1 and 2. In the figure, 1 is a gas nozzle, 2 is a torch body, 3 is a wire guide, 4 is an electrode tip, and 5 is a welding wire. Guided in the direction of A, code 7
Shield the area around the area where the arc occurs as shown in .

In FIG. 1, the gas nozzle 1 and the torch body 2 are connected by a threaded portion 8. As shown in FIG. This screw-in structure is the most common, but the screw portion 8 tends to loosen due to vibration during use, and the nozzle replacement operation is troublesome, so it is not suitable for automatic replacement.

In the example shown in FIG. 2, the gas nozzle 1 and the torch main body 2 are connected by insertion, and the gas nozzle 1 is installed from the direction of arrow B. A ring spring 9 is attached to the torch body 2, and when the gas nozzle 1 is attached, the ring spring 9 expands and engages with a groove 10 on the inner circumference of the gas nozzle 1 to prevent it from coming off. This structure makes the nozzle replacement operation easy and is suitable for automatic replacement, but due to thermal expansion and wear caused by the temperature rise of the gas nozzle 1, the gap between the joint between the gas nozzle 1 and the torch body 2 becomes large, and air enters the nozzle through this gap. It may be sucked in and cause weld defects.

An object of the present invention is to provide an arc welding torch that allows easy automatic replacement of the gas nozzle, prevents the nozzle from loosening, prevents air from being sucked into the nozzle, and is highly reliable.

In order to achieve the above object, the present invention attaches to the gas nozzle a cylindrical holder that movably holds the gas nozzle in the direction of the nozzle axis and a compression spring that pushes the gas nozzle toward the torch body. The gas nozzle is plugged into the torch main body by engagement with the groove, and when the gas nozzle is connected, one end surface of the gas nozzle is pressed against the end surface of the torch main body by a compression spring.

FIG. 3 shows an embodiment of the present invention, in which a shows the state before the nozzle is installed, and b shows the state after the nozzle is installed. In FIG. 3, parts corresponding to those in FIGS. 1 and 2 are given the same reference numerals, and explanations of common structures will be omitted.

The gas nozzle 1 is fitted inside a cylindrical holder 11 and is held movably in the nozzle axial direction, and is prevented from coming off by a retaining ring 13. compression spring 12
is interposed between the outer stepped portion 14 of the gas nozzle 1 and the inner stepped portion 15 of the cylindrical holder 11, and acts to push the gas nozzle 1 toward the torch body 2 side. This gas nozzle 1, cylindrical holder 11, and compression spring 1
2 is treated as a nozzle assembly. Reference numeral 16 denotes a groove for coupling with the torch body provided on the inner circumference of the cylindrical holder 11, and a ring spring 17 that engages with this groove 16 is mounted on the outer circumference of the torch body 2. A groove 18 provided on the outer circumference of the cylindrical holder 11 is used to set the nozzle assembly in a jig 20 shown in FIG. 4 during automatic gas nozzle replacement. 19,
Reference numeral 19 denotes a tapered surface formed at opposing ends of the gas nozzle 1 and the torch body 2.

We will explain how to replace the nozzle when it is used in a robot. When installing the nozzle, use the fourth
As shown in Figure 3a, the nozzle assembly is set on the claw 21 of the jig 20, and the torch body 2 fixed to the arm (not shown) of the robot is moved to the previously taught position by arrow D in Figure 3a. lower it in the direction of When the torch body 2 is inserted into the cylindrical holder 11, the gas nozzle 1 and the tapered surfaces 19, 19' of the torch body 2 first come into contact, then the compression spring 12 is deflected, and the gas nozzle 1 descends together with the torch body 2. Then, the ring spring 17 is attached to the cylindrical holder 11.
The torch body 2 stops descending at the position where it fits into the groove 16, and the installation of the nozzle assembly to the torch body is completed. In the installed state, the cylindrical holder 11 is coupled to the torch body 2 by the engagement of the ring spring 17 and the groove 16, and the compression spring 12
Gas nozzle 1 and torch body 2 are
The tapered surfaces 19, 19' of are compressed. The gas nozzle 1 and the torch body 2 may be in contact with each other on a flat surface, but in order to prevent air leakage, the tapered surfaces 19, 1
Better results can be obtained by contacting at 9'.

When removing the nozzle assembly from the torch body, it is sufficient to move the torch body 2, fit the groove 18 of the cylindrical holder 11 into the pawl 21 of the jig 20, and then pull up the torch body 2. This work can also be performed automatically by teaching the robot in advance.

As explained above, the arc welding torch according to the present invention allows the gas nozzle to be attached simply by inserting the torch body into the cylindrical holder that holds the gas nozzle. Easy to replace. Moreover, according to the present invention, when the gas nozzle is installed, one end face is always crimped to the end face of the torch body by a spring. Air is not mixed into the shielding gas through a gap between the gas nozzle and the torch body caused by thermal expansion or wear, and a healthy arc shield can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an example of a nozzle mounting structure in a conventional arc welding torch, and Fig. 2 is a diagram showing another example of a nozzle mounting structure in a conventional arc welding torch, where a is a longitudinal sectional view and b is a longitudinal sectional view. is that C-
C' sectional view, Figure 3 is an embodiment of the present invention, a is a longitudinal sectional view showing the state before the nozzle is attached, b is a longitudinal sectional view showing the state after the nozzle is attached, and Figure 4 is the nozzle attachment and detachment. 1 is a diagram showing an example of a jig, in which a is a side sectional view with a nozzle assembly set, and b is a perspective view of the jig. 1...Gas nozzle, 2...Torch body, 11...
...Cylindrical holder, 12...Compression spring, 13...Retaining ring, 16...Groove for coupling the cylindrical holder and torch body, 17...Ring spring, 19, 19'...
...The end surface (tapered surface) where the gas nozzle and the torch body are crimped.

Claims (1)

[Scope of utility model registration request] A cylindrical holder that movably holds the gas nozzle in the direction of the nozzle axis is attached to the gas nozzle that guides the shielding gas to the welding part, and a cylindrical holder that is interposed between the cylindrical holder and the gas nozzle and works to push the gas nozzle toward the torch body. A compression spring is attached, and the cylindrical holder is removably connected to the torch main body by engagement between the ring spring and the groove, and when the cylindrical holder is connected, one end surface of the gas nozzle is brought into contact with the end surface of the torch main body by the compression spring. Arc welding torch made to be compressed.