JP3090702B2 - Method of manufacturing electrode structure for electron gun - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electrode assembly for an electron gun for a cathode ray tube, for example, from a thin plate material by pressing.

[0002]

2. Description of the Related Art An electron gun for a cathode ray tube comprises a large number of electrode assemblies, and these electrode assemblies are produced by pressing a thin plate material. As an example of this electrode structure, No. 1 for an in-line color CRT is used. 6 shows a grid cup in FIG. The electrode assembly 11 has a depth stop as shown quite deep, and apertures 12, 13 and 14 of the electron beam formed in the top surface portion 11a is considerably larger than the hole pitch in a non-circular. It is important that the dimensional accuracy of each part and the flatness of the top surface part are high.

[0003] A conventional method of manufacturing such an electrode assembly is described below.
Figure5Will be described. First, a predetermined coil material (not shown)
Et al.5A blank is obtained as shown in FIG. next,
Figure5(B) Figure5Squeeze in order as shown in (c) and cap
And protrude. Cap-shaped molding formed in this way
On the top of the product5As shown in FIG.
Drill the sub-beam passage hole. After this, for drawing
Edge trimming is performed to remove the resulting edge, and5
An electrode having the shape shown in (e) is completed.

In the above-described manufacturing method, in the drilling and edge cutting process, the strain generated during the former drawing process is released at a stroke. Therefore, even if the dimensions at the time of drilling are high precision, the dimensions may change during edge cutting. As a result, there is a problem that the dimensional accuracy is deteriorated. That is, in the actual punching process, when the punch is pulled out of the workpiece, the hole is smaller than the punch size. For this reason, when a hole guide is used as a guide for a trimmed product in the subsequent trimming step, the trim guide pin is difficult to enter the hole of the processed product, and the hole may be deformed because it is forcibly inserted.

[0005] Further, when a large hole is formed at the same time when the hole is punched, the force of the punched waste to bite into the hole die becomes large, so that the hole die is easily damaged.

Furthermore, if the outer shape is trimmed at the time of trimming, the bottom flange portion of the product spreads out, and the dimensional accuracy of the trimming deteriorates.

[0007]

As described above, in the conventional manufacturing method, the processing strain generated at the time of drawing is released at a stroke at the time of the subsequent drilling and edge cutting, so that the dimensions of the hole and the like change. There is a problem that comes off from.

[0008] An object of the present invention is to release most of the processing distortion, and then perform drilling and edging into the original shape to prevent the occurrence of defective products, and to provide a high-quality electrode assembly for an electron gun. It is an object of the present invention to provide a method for manufacturing an electrode structure for an electron gun, which can obtain the following.

[0009]

According to the present invention , a thin sheet material is formed into a cup shape by drawing, and a through hole having a predetermined shape is formed by punching the top surface thereof, and an edge generated by the drawing is removed. In performing the edging, before forming the passage hole of the predetermined shape, at the formation location of this passage hole,
Drill a pilot hole having an area smaller than this passage hole, and then perform main hole drilling to drill the passage hole of the predetermined shape ,
Before edging, make the shape larger than this original edging shape.
Perform lower edge trimming, and then trim to the original shape.
This is to perform the main cutting .

[0010]

According to this structure, after the thin plate is drawn into a cup shape, by cutting the lower edge, a considerable unnecessary portion of the processed product having the processing distortion is cut off.
Most of the distortion generated during drawing can be removed. Therefore, if the main trimming is performed afterwards to perform the trimming to the original trimming shape, the deviation of the dimensions of each part is minimized, and a high-quality product can be obtained.

[0011]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a process for manufacturing the completed electrode assembly 11 shown in FIG. 4 by a single press or a transfer press.

In FIG. 1, (a) to (c) are diagrams
5 Same as the conventional method described in (a) to (c). That is, a rectangular blank shown in the figure is obtained from a predetermined coil material, and the blank is sequentially drawn and formed into a cap. The blank is rectangular in the figure, but may be circular or elliptical.

Next, as shown in FIG. 1 (d), a pilot hole is made in the top surface of the cap-shaped molded product molded as described above. That is, passage hole 1 of the original electron beam shown in FIG. 4
Prepared holes 12a, 13a, 14a having a smaller hole area than the through holes 12, 13, 14 are formed at locations where the holes 2, 13, 14 are formed, and the distortion of the top surface 11a is removed. The pilot holes 12a, 13a, 14a and the original passage holes
When a transfer press is used, the dimensional difference from 12, 13, and 14 is set to about 1.5 times the plate thickness on one side.

After drilling the pilot hole, a lower edge is cut as shown in FIG. That is, the lower edge is cut into a shape larger than the original edge shape with respect to the edge generated by the drawing process in the preceding stage. When a transfer press is used, the dimensional difference between the lower edge shape and the original edge shape is set to about 1.5 times the plate thickness on one side. Since the transfer press is used, the shape after the lower edge cutting is not similar to the original edge cutting shape, but a shape having a product holding portion 11b as shown in the figure. This product holding portion 11b is not necessary for processing by a single press, but is used in subsequent steps when a transfer press is used.

In the lower edge cutting step, the scrap 11c indicated by oblique lines in FIG. 1 (e) has a shape connected to one, so that it is effective against floating of debris and the scrap 11c is placed in the mold. Processing is easy.

Next, as shown in FIG. 1F, main holes for forming the original electron beam passage holes 12, 13, 14 are formed. At the time of the main drilling, as shown in FIG. 2, the processed product is carried to the processing position by the finger 16 and positioned, and then the product pressing portion 11 is moved by the upper product pressing pin 17 (not shown).
Hold down c. Therefore, the processed product can be held and fixed at a predetermined processing position even after the finger 16 is opened. The product holding pin 17 holds and fixes the finger 16
Works similarly when the product is closed and grabbed.

The original electron beam passage holes 12, 13, and 14 formed by the main hole hardly change in shape, and maintain high dimensional accuracy. In other words, since most of the accumulated processing distortion during drawing was cut off by the lower hole drilling and lower edge cutting in the former stage, the shape of the through holes 12, 13, 14 hardly changed after the main hole was drilled .

FIG. 3 shows the state of the above-mentioned perforation. The main perforation die 18 and the punch 19 are used for the top surface 11a of the workpiece after the perforation. Dawn processing is performed. In the case of this main hole, the ratio of the hole diameter to the hole pitch of the passage holes 12, 13, and 14 becomes large, so that the die 18 becomes thin, and in general, the die 18 is easily damaged by punched scum. However, according to the present invention, since the pilot hole is formed in the preceding stage, as shown in FIG. 3, the pilot hole 12a (13a, 14a) is formed in the punched ditch 11d.
a (13a, 14a) is deformed inward.
The biting force on the die 18 is reduced, and the breakage of the die 18 is prevented. At this time, if the dregs 11d are pulled by vacuum, air enters through the prepared holes 12a (13a, 14a), which is also effective in preventing the dregs 11d from floating.

Finally, as shown in FIG. 1 (g), the main trimming is performed, and the hatched portions shown as scraps 11e are removed to trim the original shape. Since the lower edge is cut off as described above and most of the processing distortion is cut off, the product shape after the main edge hardly deforms, and a high-quality product is obtained. Can be Further, since the scrap 11e has a single shape, the scrap 11e is effective against floating of scraps, and the scrap 11e can be easily processed in a mold (not shown).

Here, the dimensional difference between the lower hole and the main hole and the dimensional difference between the lower edge and the main edge are set to about 1.5 times the plate thickness on one side, respectively, for the following reason. .
Generally, the forward feed is set to about 1 to 2 times the sheet thickness. In the case of the present invention, it is desirable to set the lower edge cutting as small as possible with respect to the main edge cutting, and it is preferable to set the lower hole opening as large as possible with respect to the main hole opening. However, when processing by a transfer press, the feeding accuracy to the next process is not very good, and there is also a problem of rotation of the processed product at the time of feeding, and as described above, a dimensional difference of about 1.5 times the plate thickness is caused. Set .

[0022]

As described above, according to the present invention, the dimensional accuracy of the electron beam passage hole and the like can be maintained higher than before, and a high-quality product can be obtained .

[Brief description of the drawings]

FIG. 1 is a process diagram showing one embodiment of a method for manufacturing an electrode structure for an electron gun according to the present invention.

FIG. 2 is a perspective view showing a state of holding a processed product in the present invention.

FIG. 3 is a cross-sectional view showing a main boring state in the present invention.

FIG. 4 is an electrode structure for an electron gun made by the method of the present invention .
It is a perspective view which shows one Example.

FIG. 5 is a process chart showing a conventional method.

[Explanation of symbols]

11 Electrode assembly 11a Top surface 12,13,14 Through hole 12a, 13a, 14a Prepared hole

Claims (1)

(57) [Claims] An electrode structure for an electron gun which forms a thin plate material into a cup shape by drawing, forms a through hole of a predetermined shape by punching the top surface thereof, and performs trimming for removing an edge generated by the drawing process. In the manufacturing method of (1), before forming the through hole having the predetermined shape, a lower hole having an area smaller than that of the through hole is formed in a place where the through hole is formed, and thereafter, a main hole that forms the through hole having the predetermined shape is formed. An electrode assembly for an electron gun, comprising: performing opening and performing a lower edge trimming to a shape larger than the original edge shape before the edge trimming, and then performing a main edge trimming to an original shape. Manufacturing method.