JPS5825548B2 - Electric power supply - Google Patents

Description

Detailed Description of the Invention The present invention is an electric welding method called resistance welding or spot welding, in which the objects to be welded are welded together by bringing a welding electrode and a receiving electrode into contact with the objects. Regarding.

In order to support the aperture grill of a color television receiver on the cathode ray tube inside the cathode ray tube, a leaf spring mounting plate is attached to the frame of the aperture grill by electric welding.

Spot welding is used to attach the leaf spring mounting plate, and the welding electrode is brought into contact with the mounting plate placed in contact with the frame of the aperture grille, and the receiving electrode is brought into contact with the frame. I have to.

The contact surface of this receiving electrode that comes into contact with the frame is configured in a spherical shape, thereby preventing the corner portions of the receiving electrode from coming into contact with the frame.

However, since the contact between the frame and the receiving electrode is almost point contact and the contact area is very small, the temperature during welding becomes high, and the part of the frame that comes into contact with the receiving electrode softens, melts, or thermally deforms, causing the frame to fall into place after welding. A so-called splash remains.

If this splash was left, there was a problem in that the electron beam would hit this splash, creating a shadow on a portion of the image being played back on the cathode ray tube.

Conventionally, this splash was removed after welding, but this required a lot of man-hours and was a troublesome process.

The present invention has been made in order to correct such problems, and includes providing an auxiliary electrode support part for supporting an auxiliary electrode on the receiving electrode, and a workpiece to be welded that is disposed opposite to the receiving electrode. An auxiliary electrode having a power receiving surface having substantially the same shape as the surface facing the receiving electrode is supported by the auxiliary electrode supporting portion, and at this time, play is provided between the receiving electrode and the auxiliary electrode, and the receiving electrode and the workpiece are welded. The auxiliary electrode is interposed between the auxiliary electrode and the auxiliary electrode so that the power receiving surface of the auxiliary electrode is a surface facing the receiving electrode of the object to be welded so as to come into contact with the object to be welded.

Therefore, according to the present invention, since the auxiliary electrode provided on the receiving electrode side makes surface contact with the object to be welded over a relatively wide area, the temperature during welding in this part is relatively low, and there is no splash or heat. Deformation can be effectively prevented and a preferred electric welding method can be provided.

An embodiment in which the present invention is applied to a method of attaching a leaf spring mounting plate to an aperture grill of a cathode ray tube of a color television receiver by electric welding will be described below with reference to the drawings.

As shown in FIG. 1, the aperture grill 1 of this cathode ray tube is formed by forming a large number of slits 2 in a steel plate, and is fixed to upper and lower parts 4 and 5 of a frame 3 while maintaining tension.

The upper and lower parts 4 and 5 of the frame 3 are formed into a thick L-shape in cross section.

Further, the left and right parts 6 and 7 of the frame that connect the upper and lower parts 4 and 5 of these frames 3 on both sides have a rectangular cross section, and the upper and lower parts 4 and 5 of the frame 3 have a rectangular cross section.
It is continuous with these parts 4, 5 on the lower side.

That is, these upper and lower parts 4, 5 and left and right parts 6,
7 is integrally formed by being joined by welding.

The aperture grill 1 attached to the frame 3 as described above is arranged inside a color cathode ray tube (not shown) so that the aperture grill 1 faces a fluorescent surface.

For this purpose, the frame 3 has three leaf spring mounting plates 8, 9 and 10 on its outer periphery and these mounting plates 8゜9.
．． Leaf springs 11 and 12゜13 paired with 10
are installed respectively.

That is, mounting plates 8 and 9 and leaf springs 11 and 12 are attached to the left and right portions 6 and 7 of the frame 3, respectively.

Further, a mounting plate 10 and a leaf spring 13 are attached to the lower portion 5 of the frame 3.

Approximately triangular holes 14, 15, 16 are formed at the tips of the three leaf springs 11, 12, 13, respectively, and three studs fixed inside the cathode ray tube are inserted into these holes 14, 1516. By receiving and engaging pins (not shown), the aperture grille 1 is elastically held within the cathode ray tube and properly positioned.

The three leaf spring mounting plates 8, 9, and 10 are fixedly attached to the frame 3 by electric welding.

In the following, the method for installing the lower part 5 of the frame 3 and the leaf spring mounting plate 10 by electric welding will be explained in the second section.
This will be explained with reference to FIGS.

First, the frame 3 of the aperture grill 1 is fixed by some method.

The mounting plate 10 is then held in contact with the outer surface 17 of the lower part 5 of this frame 3.

This holding method is carried out, for example, by using a jig to properly position and contact the outer surface 17 of the lower part 5 of the frame 3.

Next, the welding electrode 21 is brought into contact with this mounting plate 10.

The electrode 21 is made of copper, and its tip is made of Elcon (sintered metal of silver and tungsten).

This welding electrode 21 is attached to the tip of the piston rod 24 of the piston 23 of the air cylinder 22,
When air is fed into the cylinder 22, the piston 23 moves forward, thereby pressing the welding electrode 21 against the mounting plate 10. When the air supply is stopped, the restoring force of the spring 25 housed in the cylinder 22 causes the welding electrode to 21
is configured to be spaced apart from the mounting plate 10.

On the other hand, on the inner surface 18 of the frame 3, a receiving electrode 26 made of copper is arranged opposite to this surface.

This receiving electrode 26 is housed and held within a cylindrical holder 27.

The power receiving surface 29 of the receiving electrode 26 is formed of an ercon (sintered metal of silver and tungsten) and has a spherical shape.

The holder 27 is fixed to the tip of a U-shaped arm 30 fixed to the cylinder 22.

The power receiving surface 29 of this receiving electrode 26 and the inner surface 18 of the frame 3
An auxiliary electrode 31 made of, for example, a sintered metal of silver and tungsten (trade name: Elcon) is interposed between the two electrodes.

The reason for using Elcon is that copper ions are not generated when the aperture grill 1 is enclosed in a cathode ray tube.

The auxiliary electrode 31 is supported by an auxiliary electrode support 32 placed below it.

An arm 33 is connected to the support body 32 at the rear thereof.

A screw 35 is inserted into the elongated hole 34 formed in this arm 33.
The holder 32 is attached to the holder 27 by inserting the screw 35 into a screw hole formed in a cylindrical part 36 provided at the bottom of the holder 27 of the receiving electrode. .

The holding portion 38 of this holding body 32 is formed with a clearance in the width direction and thickness direction of the auxiliary electrode 31.

The inner surface 18 of the frame 3 that comes into contact with the auxiliary electrode 31 is substantially linear in its thickness direction (vertical direction in FIG. 2).

However, it has a circular arc shape in its length direction (vertical direction in FIG. 3).

That is, its radius of curvature is R1.

The value of this R1 is, for example, about 1,500 mm. Corresponding to the fact that the inner surface of the frame 3 is formed in a circular arc shape, the surface 37 of the auxiliary electrode 31 that contacts the inner surface 18 of the frame 3 is also formed in a cross-sectional shape in the width direction. ing.

That is, the radius of curvature is R2.

The radius of curvature R2 is approximately the same value as the above-mentioned R1, for example, approximately 1,500 degrees.

Therefore, when the auxiliary electrode 31 is pressed against the frame 3, the auxiliary electrode 31 easily follows the inner surface 18 of the frame 3 because it is supported by the support with a clearance in the width direction and thickness direction. Moreover, since the curvature R2 of this auxiliary electrode substantially matches the curvature R1 of the inner surface of the frame 3, the two come into contact over a relatively wide area.

Therefore, even if current flows, the contact resistance is small and the temperature of the contact area between the two does not rise, so there is no splash on the inner surface 18 of the frame 3 or thermal deformation of the frame 3. This is extremely desirable.

The auxiliary electrode 31 is elastically pressed against the inner surface 18 of the frame 3 by the air cylinder 22 via the arm 30 and the receiving electrode 26.

That is, if air is further supplied to the air cylinder 22 after the welding electrode 21 is pressed by the air cylinder 22 through the leaf spring mounting plate 10 and comes into contact with the fixed frame 3, the piston 23 will not move this time. So,
The cylinder casing 22 moves to the right in FIG. 2 along with the block 39 while being guided by the guide shaft 40, and the arm 30 fixed to the cylinder 22 also moves in the same direction.

Therefore, the receiving electrode 26 held by the holder 27 fixed to this arm 30 comes into contact with the auxiliary electrode 31, and the auxiliary electrode 31 is thereby pressed by the air cylinder 22, so that the auxiliary electrode 31 is pressed inside the frame 3, which has the same curvature. It comes into close contact with the side surface 18.

In this state, a current of a predetermined voltage is applied to the welding electrode 21 and the receiving electrode 2.
The leaf spring mounting plate 10 is fixed to the outer surface 17 of the frame 3 by the desired electric welding.

Next, the air cylinder 22 is switched and the piston 23 is moved back by the spring 25, and then the entire welding apparatus shown in FIG. 2 is moved horizontally (downward in FIG. ) move the third
The frame 3 and the mounting plate 10 are connected to each other at the positions indicated by imaginary lines in the figure.
spot weld.

By sequentially repeating the same steps as described above for the left and right parts 6, 7 of the frame 3, the leaf spring mounting plates 8.9 are similarly fixed to the frame 3.

The present invention has been described above with reference to Examples, but the present invention was explained in Example 3.
The present invention is not limited to 8, but covers a range based on the technical idea of the present invention.

For example, in the above embodiment, the present invention is applied to a method for attaching a leaf spring mounting plate to the aperture grill of a cathode ray tube of a color television receiver, but the present invention is not limited to this and can be applied to a wide range of spot welding methods. Applicable to electric welding by

Furthermore, the shape of the part to be welded in the above embodiment has a circular arc shape in the length direction and a straight line in the direction perpendicular to this shape, but it is not limited to this shape and can be applied to various shapes. It is.

Further, in the above embodiment, the auxiliary electrode support body is made to have some play with respect to the auxiliary electrode, but the auxiliary electrode support body may have play with respect to the auxiliary electrode, but the auxiliary electrode may be made to have a swinging motion, or the auxiliary electrode may be made to swing. The electrode support may be supported with some play relative to the holder of the receiving electrode.

As explained above, the present invention provides a receiving electrode with a supporting part for supporting an auxiliary electrode, and supports an auxiliary electrode having almost the same shape as the workpiece to be welded, which is arranged opposite to the receiving electrode, on the supporting part. The receiving electrode and the auxiliary electrode are made to have a play between them, so that the auxiliary electrode is brought into contact with the workpiece by being brought into contact with the workpiece.

Therefore, according to the present invention, the object to be welded and the auxiliary electrode come into contact over a relatively wide area, and the contact resistance at this contact portion becomes small.

Therefore, the temperature at the contact portion between the auxiliary electrode and the workpiece is kept low, so that the workpiece is prevented from melting or softening during welding, and splash is prevented from occurring.

Furthermore, since the temperature of the contact portion is low, the workpiece to be welded will not be thermally deformed.

[Brief explanation of drawings]

The drawings show an embodiment in which the present invention is applied to a method of attaching a leaf spring mounting plate to the aperture grill of a cathode ray tube of a color television receiver by electric welding. FIG. 2 is a longitudinal sectional view showing a state in which a mounting plate is attached to the frame of an aperture grill by electric welding, FIG. 3 is a plan view thereof, and FIG. 4 is an exploded perspective view showing a state in which an auxiliary electrode is attached. In addition, in the symbols used in the drawings, 3 is a frame;
10 is a leaf spring mounting plate, 21 is a welding electrode, 26
27 is a receiving electrode, 27 is a holder, and 31 is an auxiliary electrode.

Claims (1)

[Claims] 1. In an electric welding method in which the objects to be welded are welded together by bringing a welding electrode and a receiving electrode into contact with the objects to be welded,
The receiving electrode is provided with an auxiliary electrode support part for supporting the auxiliary electrode, and the auxiliary electrode has a power receiving surface that is approximately the same shape as a surface facing the receiving electrode of the workpiece disposed opposite to the receiving electrode. The auxiliary electrode is supported by the auxiliary electrode support part, and at this time, a play is provided between the receiving electrode and the auxiliary electrode, and the auxiliary electrode is interposed between the receiving electrode and the workpiece to cover the power receiving surface of the auxiliary electrode. An electric welding method characterized in that the surface of the workpiece facing the receiving electrode is brought into contact with the workpiece.