JPS58184078A - Laser welding of fitting part - Google Patents

Abstract

PURPOSE:To improve yield by providing notches and slits in one of this fitting parts, deforming the weld zone and performs laser welding, and thereby bringing the amount of the fitting gap to zero. CONSTITUTION:Notches and slits are provided at two places near the welding point 11 of a cap 10, a fitting part, to make the side wall 13 of the cap 10 easily plastic deformable from the direction of outer periphery. A sleeve 14 and the cap 10 positioned by an assembling mandrel 16 and a pressing mandrel 17 are moved from direction of the arrow by a pressing plate 15 to deform the side wall 13. After bringing the gap into close contact, the cap is welded by irradiating a laser beam 20 from a laser device 19 to the weld zone of the sleeve 14.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of laser welding thin-walled cylindrical parts such as cathode parts of electron tubes by fitting and assembling them together, and particularly relates to a laser welding method in which a large fitting gap stabilizes the formation of molten nuggets. .

As an example, the assembly of the cathode shown in FIG. 1 will be described below.

The conventional laser S* method is carried out as shown in FIG. The cap 2 is positioned and fitted to the sleeve 1 made of a metal cylindrical component with a wall thickness of 20 μm using the assembly core 3 and the presser core 4, and the welding point 5 on the outer periphery of the cap 2 (Fig. 1) is assembled. The laser beam 7 emitted from the laser device 6 is fixed in contact with the laser beam #I at multiple points.

Incidentally, the sleeve 1 and the cap 2, which are positioned by the assembly core bar 3 and the presser core bar 4, have gaps at the fitting portions 8 and 9. This gap amount cannot be completely eliminated due to the ease of assembling the sleeve 1 and cap 2 and the manufacturing tolerance of the fitting part, and is usually from 10 μm to several hundred μm.
μm, and in this state the V− emitted from the laser device 6
Welding is done using the Beam 7.

Generally, in the case of laser welding, it is known that welding is difficult if there is a gap, and if the gap amount becomes large or varies, welding tolerance problems will occur. As a countermeasure to this problem, production is managed by reducing the tolerance of the fitting part by negotiating limit values, and by maintaining and improving the accuracy of assembly machines and controlling the gap amount within 20 x m, but there are bottlenecks in terms of manufacturing costs and quality control. It becomes.

The object of the present invention is to make it possible to bring the amount of the fitting gap as close as possible to zero without increasing the precision due to the assemblability of the fitting parts and the manufacturing tolerance of the parts, and to achieve a stable fitting with a wide hemorrhoidal tolerance. An object of the present invention is to provide a method for laser welding parts.

Hereinafter, one embodiment of the present invention will be explained with reference to FIG. 3. The shape of the cap 10 of the mating part is as shown in Fig. 4, with two notches and slits 12 provided near the welding point 11 (see Fig. 116), so that the side wall 13 of the cap 1° can be easily plastically deformed from the outer circumferential direction. Shape the cap so that In order to bring the side wall portion 13 into close contact with the sleeve 14,
A bifurcated holding plate 15 shown in FIG. 5 φ is used.

Next, the 1+11!1 method will be explained. After moving the sleeve 14 and cap 10, which have been positioned by the assembly core bar 16 and the presser core bar 17, in the direction of the arrow 18 using the presser plate 15 to deform the side wall portion 13 and bring the gap portion into close contact, the laser of the laser device 19 is moved. The beam 2° is irradiated onto the welded portion of the sleeve 14. As a result, the cathode shown in FIG. 6 is obtained.

In this way, since laser welding is performed with the fitting gap amount close to zero, stable welding can be performed.

Although the present embodiment has been described with reference to the fitting of cylindrical parts, the cross section of the fitting part can also be square or irregularly shaped, and the product shape is not limited.

The feature of laser welding of the present invention is that the base material to be welded is as thin as micrometers, and the flow phenomenon of molten metal is small, making it ideal for laser welding of close-fit parts such as high melting point alloys such as tungsten and molybdenum, chromium, and titanium alloys. However, by applying it to parts that fit relatively thick plates in the millimeter scale, which have conventional welding margins and are considered to have no problems, it is possible to reduce welding spatter and lower the energy density of the fused part, making it possible to It is possible to downsize and reduce power consumption, and it also has great effects such as improving yield due to quality improvement and eliminating inspection man-hours.

[Brief explanation of the drawing]

3111 is a partially cutaway perspective view of a conventional cathode, FIG. 2 is a partially sectional front view of a conventional laser welding method, and FIG. 3 is a partially sectional front view showing an embodiment of the present invention. , FIG. 4 is a perspective view of the cap shown in FIG. 3, FIG. 5 is a perspective view of the holding plate shown in FIG. 3, and FIG. 116 is a perspective view of the cathode obtained by the method shown in FIG. 3. lO... Cap, ' 11... #l contact, 12... Slit, 13... Side wall portion, 14... Sleeve, 15... Holding plate, 19... Laser device, 20. ...Laser beam.

Claims (1)

[Claims] In a method of laser welding the fitting part of thin-walled fitting parts,
A method for laser welding fitting parts, characterized in that one fitting part is provided with a slit, and the welding part is deformed in a direction to reduce the fitting gap of the l# joint part, and laser welding is performed.