JPH037088Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a plasma arc torch that directs a plasma arc obliquely and is used for welding, cutting, thermal spraying, etc. in narrow spaces.

[Conventional technology]

Conventional plasma torches used for plasma welding, plasma cutting, etc. have an electrode installed in the axial direction of the main body, and a plasma nozzle installed in the axial direction, and are used in wide areas such as flat plates. is normal.

Recently, the development of a flat torch that can be used for narrow gap welding has been considered, but since the electrode and plasma nozzle are installed on the same axis, the initial layer in the U groove may be affected due to arc spread, etc. Currently, it is only used for welding.

In addition, as a method of tilting the plasma direction with respect to the torch body, Japanese Patent Application Laid-Open No. 58-81563 discloses that an electrode is held in an inclined state on the torch body, and a plasma nozzle is installed on the axis of this electrode to direct the plasma. An example of use in gouging is disclosed, but in this example the torch is large and the plasma arc is unstable, making it impossible to use for welding in narrow spaces.

[Problem that the invention attempts to solve]

The present invention takes these drawbacks into consideration and aims at a plasma arc torch that can be used for welding, cutting, thermal spraying, etc. in confined spaces.

[Means for solving problems]

The present invention provides an electrode provided in the axial direction of the plasma arc torch main body, and a straight plasma nozzle hole centered in a direction inclined at an angle θ from the axis, and the inner diameter of the nozzle hole on the electrode side and the electrode surface are The present invention provides a plasma arc torch that uses spherical electrodes spaced at regular intervals and directs plasma obliquely to the axis of the torch body to perform fillet welding or distributed welding in narrow areas.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings. Figure 1 is a front view (a) and a side view (b) (both sectional views) of the plasma arc torch (tip part) of the present invention, in which 1 is an electrode provided in the axial direction of the torch body, and is made of heat-resistant insulating material. A pilot gas passage 3 is provided and a nozzle tip base electrode 4 is provided. This nozzle tip stand 4 has a straight nozzle hole 1 whose center line is inclined at an angle θ45° with respect to the axis of the electrode 1 in this embodiment.
The tip of the electrode 1 is ground into a hemispherical shape so that the inner diameter of the nozzle hole 10 of the nozzle tip 9 on the electrode 1 side and the surface of the electrode 1 are at a constant interval. The body is configured such that the center of the body is located on the center line of the nozzle hole. A distance of 0.5 to 1.5 mm is optimal for achieving stability of the plasma arc. The nozzle tip base 4 is provided with water channels 5 and 6 for cooling water, which rotate in order at the tip.

Further, a shield cap 8 made of a ceramic material, which is a heat-resistant insulating member, is provided on the outer periphery of the nozzle tip holder 4, and a shield cap 8 is provided with a shield gas passage 7, and a shield hole 11 is provided in the direction of the inclination of the nozzle 9. FIG. 2 is a sectional view taken along the line A-A' in FIG. 1 of the torch of the present invention. FIG. 3 shows an example of the shape of the shield hole 11 according to the view taken along arrows B-B' in FIG. However, if this is done as in this example, and this will be explained based on FIG. 3, shielding gas is more likely to come out in the left and right directions in the drawing, so the left and right directions of the plasma arc are more easily cooled than the up and down directions. As a result, the plasma arc becomes an arc with an oval cross section that extends vertically in a direction perpendicular to the welding line. This effect is such that when this torch is used for welding, the plasma arc spreads in the left and right directions in the welding direction, resulting in a good bead shape welding result. The tip of the electrode 1 is made into a spherical body so that the inner diameter of the nozzle hole 10 on the electrode 1 side and the surface of the electrode 1 are at a constant interval.
At the center of 0, the electrode 1 protrudes, so a stable plasma arc can be obtained.

Further, in this example, the nozzle 9 is tilted at an angle of θ45°, but good results can be obtained with the above structure at any angle. Note that the type and material of the gas and electrodes used are subject to change depending on the applicable member to which this torch is used, and are not regulated.

[Effect of idea]

As described above, the plasma arc torch of the present invention is designed to be inserted into a narrow part and to direct the plasma arc particularly toward the corner. Alternatively, by using a filler metal, distributed layer welding with a narrow gap can be performed. It also has the great effect of expanding the use of plasma arc as a construction method for narrow spaces using thermal spraying or plasma hot wire.

[Brief explanation of drawings]

Fig. 1 is a front and side sectional view showing an embodiment of the plasma arc torch of the present invention, Fig. 2 is a sectional view taken along line A-A' in Fig. 1, and Fig. 3 is a plan view of the shield hole. . In the drawing, 1 is an electrode, and 10 is a plasma nozzle hole.

Claims (1)

[Scope of utility model registration request] A spherical electrode having an electrode provided in the axial direction of the main body and a straight plasma nozzle hole centered in a direction inclined by an angle θ from the axis, and the inner diameter of the nozzle hole on the electrode side and the electrode surface are at a constant interval. A plasma arc torch characterized by: