JP3130606B2 - Method of manufacturing support frame for shadow mask type color cathode ray tube - 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 of manufacturing a support frame for a shadow mask type color cathode ray tube , comprising a bottom having a substantially rectangular opening and side walls vertically erected from the periphery of the bottom. The present invention relates to a method for manufacturing a support frame for a shadow mask type color cathode ray tube , which minimizes scrap generated at the time and simplifies the manufacturing process.

[0002]

2. Description of the Related Art In a shadow mask type color cathode ray tube, a support frame is used to hold the shadow mask on a front panel portion in the cathode ray tube.

Conventionally, the support frame is, for example,
It was manufactured by a method as disclosed in JP-A-62-243223.

FIGS. 3A to 3E show a manufacturing method according to the above disclosure.

In FIG. 3, reference numeral 10 denotes an iron ribbon material,
1 is an iron plate material, 12 is a joint between the ribbon material 10 and the plate material 11, 13 is a provisional opening, 14 is a punched support frame member, 15 is a punched iron scrap, 16 is a bottom portion,
17 is a side wall, 18 is a drawn support frame member, 19 is an opening, 20 is a completed support frame,
Reference numeral 21 denotes an iron scrap after punching the opening 19.

[0006] The support frame according to the manufacturing method is manufactured by the following steps.

First, as shown in FIG. 3 (a), two strips of iron ribbon 10 and a strip of iron plate 11 are prepared, and a strip of iron is placed between the two strips of ribbon 10 arranged in parallel. Are sequentially welded at predetermined intervals, and as a result, a ladder-like material having temporary openings 13 provided at regular intervals is formed. Next, as shown in FIG. 3B, in the ladder-shaped material, the provisional opening 13 is located at the center, and the area indicated by the dotted line including the ribbon material 10 and the plate material 11 adjacent to the opening 13 is shown. Punching using a press die, Fig. 3
The support frame material 14 as shown in FIG. In this process, the support frame material 1
The punched iron scrap 15 obtained after punching 4 is
After going through the processing steps described below, it is processed as scrap. Next, as shown in FIG. 3D, the punched support frame material 14 is subjected to peripheral drawing using a press die, and rises vertically from the bottom 16 having the provisional opening 13 and the periphery of the bottom 13. Side wall 1
7 is formed. Finally, as shown in FIG. 3E, the bottom portion 16 of the support frame member 18 is punched into a frame shape using a press die, and a support frame 20 having an original substantially rectangular opening 19 is formed. Note that, in this step, the punched iron scrap 21 having the provisional opening 13 is treated as scrap.

Although the conventional manufacturing method has an advantage as a continuous production line, the iron ribbon material
A sheet and an iron plate 12 are required, and need to be processed and supplied. In addition, it has disadvantages such as a long welding distance.

Recently, in order to overcome such difficulties,
A method of manufacturing a support frame has been devised in which an L-shaped member is formed by punching from a belt-shaped iron material, and after welding the two L-shaped members, a support frame member is obtained by pressing. This is called an improved manufacturing method).

FIGS. 2A to 2D show this improved manufacturing method.

In FIG. 2, reference numeral 1 denotes a band-like material made of metal, for example, iron, 2 'denotes an L-shaped blank (L-shaped member) obtained by stamping out the material 1, 3 denotes a joint between two blanks 2', and 4 denotes Bottom portion, 5 is a side wall, 6 is an opening, 7 is a punched iron scrap, and 8 is a provisional opening.

According to the improved manufacturing method, the support frame is manufactured by the following steps.

First, as shown in FIG. 2 (a), L-shaped blanks 2 'are sequentially punched from a steel strip material 1 using a press die to form a large number of L-shaped blanks 2'.
Next, as shown in FIG. 2B, the two L-shaped blanks 2 ′ are connected to each other in an abutting manner, and these connection portions 3 are joined by welding to form a frame-shaped member having a provisional opening 8. Next, as shown in FIG. 2C, the periphery of the frame member is drawn using a press die, and a bottom portion 4 having a provisional opening 8 and a side wall 5 rising vertically from the periphery of the bottom portion 4 are formed. To form a support frame member having: Finally, as shown in FIG. 2D, the bottom portion 4 of the support frame member is punched into a frame shape using a press die to form a support frame having an original substantially rectangular opening 6.

[0014]

According to the improved manufacturing method, since the L-shaped blank 2 'is punched sequentially from the strip material 1, most of the strip material 1 is effectively used, and Although the utilization rate can be improved, the final step still requires a step of punching the bottom portion 4 of the support frame member in a frame shape, so that the number of steps in manufacturing the support frame cannot be significantly reduced, Moreover, iron scrap 7 is generated during the process,
Since the scrap 7 must be scrapped,
There is a problem that cost reduction cannot be expected sufficiently.

The present invention has been made to eliminate such a problem, and has as its object to omit the final step and
An object of the present invention is to provide a manufacturing method capable of forming a support frame at low cost by realizing scrapless.

[0016]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a shadow mask type color cathode ray tube comprising a bottom having a substantially rectangular opening, and a side wall standing upright from the periphery of the bottom. In the method of manufacturing the support frame, first, L-shaped members whose inner portions correspond to the substantially rectangular shape of the opening are punched out sequentially from the strip-shaped material at a predetermined pitch. A frame-shaped member is formed by joining together, and subsequently, when the peripheral portion of the frame-shaped member is formed by drawing , the dimensional change of the opening is reduced.
A state in which the bottom is strongly held so as to be extremely small
Means for obtaining a support frame for a shadow mask type color cathode ray tube having the bottom portion and the side wall by performing the drawing forming .

[0017]

According to the above-mentioned means, the present invention provides a method for producing L
When the shaped member (L-shaped blank) is punched, the shape of the inner part is made to match the shape of the final substantially rectangular opening, so that two L-shaped members (L-shaped blank) are connected to each other. The size of the opening obtained when forming a frame-shaped member by joining to the same becomes the same as the opening size of the completed support frame, and it is not necessary to perform the punching of the opening again in the final process. The accompanying generation of iron scum is eliminated.

As a result, the number of manufacturing steps can be reduced, and a more scrapless system can be realized.
The manufacturing cost can be reduced accordingly.

[0019]

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

FIGS. 1A to 1C relate to the present invention.
FIG. 2 is a system diagram showing one embodiment of a method of manufacturing a support frame for a shadow mask type color cathode ray tube .

In FIG. 1, reference numeral 2 denotes an L-shaped blank (L-shaped member) obtained by punching the band-shaped material 1, and other components that are the same as those shown in FIG.

Then, regarding the L-shaped blank 2,
Outer 2 ₁ portions of the L-shaped conventional shown in FIG. 2 (used in the improved process for the preparation) L-shaped blank 2 '
Has the same shape as that of
_{The two} portions have a shape corresponding to the opening 6 of the actual support frame, different from the shape of the portion of the L-shaped blank 2 '. That is, the shape of the inner part of the conventional L-shaped blank 2 ′ is such that it extends linearly from the end as shown by the dotted line in FIG. In contrast to the configuration in FIG.
Shape of the inner 2 ₂ parts of the form blank 2, as shown by the solid line in FIG. 1 (a), from said end is configured in a shape that cut in inside the dotted line, as a result, inner 2 ₂ parts , So as to conform to the shape of the opening 6 of the actual support frame.

According to the manufacturing method of this embodiment, the support frame is manufactured by the following steps.

First, as shown in FIG.
For example, an iron strip material 1 is prepared, and an L-shaped blank 2 is continuously punched from the strip material 1 using a mold to form a large number of L-shaped blanks 2. In this case, in the strip material 1, one punched L-shaped blank 2
The punching position of each L-shaped blank 2 is selected so that the distance between one adjacent L-shaped blank 2 punched next is as small as possible. Next, as shown in FIG. 1 (b), the two L-shaped blank 2 in Haraawase, i.e., inner 2 ₂ parts of the L-shaped blank 2 is bonded together so as to become the inside, these L-shaped blanks The two joining portions 3 are joined by welding to form a frame-shaped member having an opening 6 inside. At this time, the opening 6 formed in the center of the frame member has the same dimensional shape as the original substantially rectangular opening 6 in the support frame. Subsequently, as shown in FIG. 1 (c), the periphery of the frame member is drawn using a press die to form a bottom 4 having an opening 6 and a side wall 5 rising from the periphery of the bottom 4. The support frame provided is formed.

By the way, in the improved manufacturing method, the provisional opening 8 having a size smaller than the original substantially rectangular opening 6 is formed in the support frame member as shown in FIG. In the draw forming step of forming the support frame member from the frame member, the bottom portion 4 is pulled outward, and the opening size of the frame member and the opening size of the support frame member often change. The opening dimension of the frame mold member is given a margin for the dimensional change at the time of the draw forming, and the original substantially rectangular opening 6 is punched again from the provisional opening 8 of the support frame member after the completion of the draw forming. I was

Here, the present inventors used a press die having a strong holding pressure, for example, a nitrogen gas-filled cylinder (Super Nitrodyne) in the drawing process to form the bottom 4 (frame) of the support frame member. When the bottom portion 4 of the mold member is strongly restrained, the dimensional change of the opening (temporary opening) 8 becomes extremely small in the drawing forming step of forming the support frame member from the frame mold member. I found that.

Therefore, in the manufacturing method of this embodiment,
First, as shown in FIG.
The shape as described above, i.e., the inner 2 is punched so as to have a shape that matches the opening 6 of the original generally rectangular from the start of _two parts, then, as that shown in FIG. 1 (b)
After the two L-shaped blanks 2 are joined together
The joining portion 3 of these L-shaped blanks 2 is welded and joined to the inside.
A frame-shaped member having an opening 6 is formed, and thereafter, FIG.
As shown in the figure, the frame-shaped member is squeezed using a press die.
When forming, the dimensional change of the opening 6 becomes extremely small.
And hold the part corresponding to the bottom part 4 firmly
The drawing process is performed, and the drawing process is finished to complete the support frame, so that the step of punching the opening 6 is unnecessary as shown in FIG.

As described above, according to the manufacturing method of this embodiment, since the support frame is manufactured directly from the frame member, the step of punching the opening 6 can be omitted, and the conventional improved manufacturing method can be used. In comparison, the number of support frame manufacturing steps can be reduced.

According to the manufacturing method of this embodiment,
Since the blank 2 is thinner than the blank 2 ′ obtained by the conventional improved manufacturing method, the strip-shaped material 1 is formed.
The blanks 2 can be punched out of the hole 6 more, and the step of punching the openings 6 can be omitted, so that the rate of occurrence of scrap can be extremely reduced.

Further, according to the manufacturing method of this embodiment,
For example, since the step of punching the opening 6 is not required,
It is necessary to weld the joint 3 corresponding to the punched part of
And the welding distance is reduced by that much, and
While those which can be shortened, effect that can reduce the manufacturing cost of the overall support frame
There is fruit .

[0031]

As described above, the shadow of the present invention is used.
According to the method for manufacturing a support frame for a mask type color cathode ray tube, the support frame is manufactured directly from the frame-shaped member, and after forming the support frame member as in the conventional improved manufacturing method, Since the step of punching the opening 6 again to obtain the support frame is omitted, the number of steps for manufacturing the support frame can be reduced.

The shadow mask type color shade of the present invention is also provided.
According to the method for manufacturing the support frame for the arc tube, since the blank 2 which is thinner than the blank 2 ′ obtained by the conventional improved manufacturing method is formed, the blank 2 is cut out from the band-shaped material 1. More blanks 2 can be punched than the conventional improved manufacturing method, and
By omitting the step of punching the opening 6, there is an effect that the rate of occurrence of scrap is extremely reduced and the material utilization rate can be significantly improved.

Furthermore, based on the two effects, there is also a secondary effect that it is Rukoto reduce the manufacturing cost of the support frame.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of a support frame manufacturing method according to the present invention.

FIG. 2 is a system diagram showing an example of a conventional improved support frame manufacturing method.

FIG. 3 is a system diagram showing an example of a conventional basic support frame manufacturing method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 strip-shaped material 2, 2 ′ blank 3 joint 4 bottom 5 side wall 6 opening 7 scrap 8 temporary opening

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 9/14

Claims (1)

(57) [Claims] 1. A method of manufacturing a shadow mask type color cathode ray tube support frame comprising a bottom having an opening having a substantially rectangular shape and a side wall vertically erected from the periphery of the bottom. An L-shaped member whose shape corresponds to the substantially rectangular opening is punched out sequentially at a predetermined pitch, and then the punched-out L-shaped members are joined together to form a frame-shaped member. When the peripheral portion of the frame member is drawn , the dimensional change of the opening is
A state in which the bottom is strongly held so as to be extremely small
A support frame having said bottom portion and said side wall by carrying out drawing in step (a) to form a support frame for a shadow mask type color cathode ray tube.