JPS60124421A - Hole working method of plate material - Google Patents

Abstract

PURPOSE:To taper with high accuracy plural adjacent hole edges to a chamfered shape by piercing a prepared hole on a base material, performing taper coining so as to escape an excess thickness in the prepared hole or the prepared hole direction and the plate thickness direction, and thereafter, punching holes to desired diameters. CONSTITUTION:When forming a tapered part of a chamfered shape in a hole edge of an adjacent hole, prepared holes 31-33 are pierced on a material 30, and subsequently, taper coinings 34-36 are executed. In this case, an excess thickness generated by the coining is escaped not only in the direction of the prepared holes 31-33 but also in the plate thickness direction in a cylindrical diameter which is a little smaller than the outside diameter of the tip of the coinings 34-36 and also roughly equal to a finished hole, by which lowering in flatness of the circumference of the hole edge is prevented. As a result, the excess thickness in the plate thickness direction becomes cylindrical parts 34a- 36a, and in the end, finished holes 37-39 are pierced and the cylindrical parts 34a-36a are removed, and tapered hole deges 34a-36b are left in the holes 37- 39. In this way, plural adjacent hole edges can be tapered to the chamfered shape with high accuracy.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method for drilling holes in plate materials. This invention relates to a method for drilling holes in a plate material, in which the edges of nine or more holes in close proximity to each other are finished smoothly.

[Background of the invention]

As a part having a plurality of adjacent holes, for example, an in-line color picture tube electron gun II as shown in FIG.
He is known for his love structure. The electrode structure 1 has a plurality of electron beam passing holes with extremely small proximity widths -1 to 4 in-line portions.The beam passing holes 2 to 4 are formed by press punching. However, if the hole edges 2a to 4a are relatively sharp if the hole edges 2a to 4a are left as they are press punched, the electric field is likely to be concentrated on the hole edges 2a to 4a, resulting in a decrease in withstand voltage characteristics.

Normally, when used as a press-punched electrode structure, processing steps such as barrel polishing and chemical polishing are performed to remove sharp parts and improve voltage resistance characteristics. However, such a method has the disadvantage that the amount of polishing and hydrogen is limited and that it requires a large amount of time.

Therefore, the inventor of the present invention removed the sharp hole m2M-48 by press working, and created a hole edge with a te and < shape as shown in Fig. 2.
I thought about changing it to b-4b. As a method for large-scale machining by pressing the electrode structure l as shown in FIG. 2, a method as shown in FIG. 3 is generally considered. As shown in the figure (a), a prepared hole 1 of a predetermined shape is formed in the material plate IO! -I3, then finish holes 14 to I6 are drilled as shown in the same figure (b), and finally, taper coining is performed on the hole edges 14a-168 as shown in the same figure (C) to form a tapered hole edge. 14
b -16b.

However, with this method, there is no point where excess thickness is absorbed during taper coining, so the roundness of the finished holes 14 to 6 and the hole edge t
There is a drawback that the degree flatness around ub~16b decreases.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for machining holes in a plate material by which a plurality of adjacent hole edges can be chamfered and tapered with high precision.

[Required 1R of the Invention] The present invention provides a hole processing method for a plate material in which a chamfered tapered portion is formed on the hole edge of a plurality of adjacent holes, in which a bottom hole is drilled in the material, and then a bottom hole is drilled in the material, and then a bottom hole is drilled in the bottom hole or in the direction of the bottom hole. Taper coining is performed to release excess thickness in the board thickness direction, and then a hole is punched to the desired diameter.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIG. First, as shown in FIG.
1 to 23, then perform large taper coining 24 to 26 on the finishing holes as shown in the figure (b) K.
Let it be absorbed by 3. Then, when finishing holes 27 to 29 are finally drilled, the hole edges of these finishing holes 27 to 29 have tapered hole edges 2a to 26 formed by the taper coinings 24 to 26.
a remains.

In this way, after taper coining 24-26, finish hole 2
7 to 29, so taper coining 24 to 26
The extra thickness to the prepared holes 2I to 23 at the time is the finished holes 27 to 29.
The roundness of the hole is not compromised. However, in this method, it is often difficult to absorb the excess meat from taper coining 24 to 26 only in the lower heating direction, and the flatness around the hole edges 24a to 26a tends to deteriorate.

FIG. 5 shows another embodiment of the present invention which further improves the method of the previous embodiment. First, as shown in FIG. 4(a), holes 31-33 are made in the material 30 in the same manner as in FIG. Taper coining 34 not only in the direction of lower heat, but also in the direction of lowering the
Excess thickness is released in the plate thickness direction within a cylindrical diameter that is slightly smaller than the outer diameter of the tip of the innings 34 to 36 and approximately equal to the finished hole, thereby preventing a decrease in flatness around the hole edges of the taper innings 34 to 36.

Due to this, the extra thickness in the plate thickness direction is the cylindrical portions 348 to 36a.
becomes. Finally, when finishing holes 37 to 39- are bored as shown in FIG. Shape-shaped hole edges 34b to 36b remain.

In this way, the excess metal generated during taper coining 34 to 36 is absorbed in two directions, the lowering direction and the plate thickness direction, and then the excess metal is removed through the finishing holes 37 to 39.
The hole edges can be tapered into a chamfered shape without impairing the roundness of the holes 37 to 39 or the flatness around the hole edges 34b to 36b.

The above embodiments can be applied not only to circular holes but also to irregularly shaped holes such as square holes and elliptical holes. Moreover, it is applicable not only to electrode structures for electron guns but also to a wide range of general processing methods.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a plurality of adjacent hole edges can be chamfered and tapered with high precision. Therefore, when the method of the present invention is applied to a method for processing an electrode structure for an electron gun, the focus characteristic of the main lens with a large diameter can be improved without enlarging the pinch of the electron beam passage hole.
An electron gun for color picture tubes with excellent image quality and withstand voltage characteristics can be obtained.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the electrode structure where the hole edge is not chamfered.
Figure 2 is a cross-sectional view of an electrode structure in which the hole edges are rounded, Figures 3 (a) to (C) are process explanatory diagrams showing the conventional processing method, and Figures 4 (a) to (C ) is a process explanatory diagram showing one embodiment of the processing method of the present invention, and FIGS. 5(a) to (C) are process explanatory diagrams showing other embodiments of the processing method of the present invention. 20, 30...Material, 21-23.31-33...
... Lower fire, 24-26. 34-36... Taper coining, 24a-268, 34b-36b-,
, hole drilling, 27-29. 37-39... finishing hole.

Claims (1)

[Claims] In a method of drilling holes in plate materials that forms chamfered taper parts on the hole edges of multiple adjacent holes, a pilot hole is drilled in the material, and then a taper is formed in the pilot hole or in the direction of the pilot hole and in the direction of the plate thickness to release excess material. Perform coining and then punch a hole to the desired diameter! A method for large-scale machining of plate materials with gL.