JPH0576733B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method of manufacturing a cylindrical part for an electron gun manufactured by ironing.

[Background of the Invention] An example of a cylindrical part for an electron gun manufactured by ironing is a cap body of an indirectly heated cathode structure.
In the indirectly heated cathode assembly, as shown in FIG. An electron emitting material 4 is adhered to the surface, and a heater 5 is housed inside the cylindrical body 2.

FIG. 2 shows the manufacturing process of a conventional cap body. First, a blank 6 of a predetermined size is punched out as shown in FIG. The cap body 3 is manufactured by applying ironing to the side wall portion of the product 7 multiple times. These series of steps are carried out in continuous production using a transfer press.

FIG. 3 shows one step of the ironing process described above.
Although the ironing process is performed in multiple steps, for convenience of explanation, the description will be made assuming that the cap body 3 is formed from the semi-finished product 7 in one step. A die 11 is fixed on the die holder 10, and a transfer slide 13 having fingers 12 is provided on the die 11 so as to be able to slide back and forth between two adjacent processes. There is a knockout 14 in the die 11.
is urged upwardly by a spring (not shown) and is fitted so as to be movable up and down, and a punch 15 is disposed above the knockout 14 so as to be movable up and down. Further, the gap between the die 11 and the punch 15 is set to be thinner than the wall thickness of the side wall of the semi-finished product 7.

Then, as shown in Figures a and b, the punch 15 descends and pushes down the knockout 14 together with the semi-finished product 7. As a result, the side wall of the semi-finished product 7 is formed by the die 11.
The cap body 3 is formed by ironing through the gap between the punch 15 and the punch 15 to reduce the thickness. Subsequently, as shown in c and d of the same figure, the punch 15 rises, and the cap body 3 is pushed up by the knockout 14 that rises due to the biasing force of the spring, and the finger 1
2 and it's gripped.

By the way, in this ironing process, since the wall is forcibly thinned as described above, the surface of the die 11 in particular generates high heat, causing a phenomenon in which the lubricating oil film runs out locally, resulting in seizures. The plastic fluidity decreases in the process, and slag is generated. Therefore, when the cap body 3 is pushed up as shown in FIG. This ironing residue is pressed onto the top surface of the semi-finished product 7 when ironing is applied to the next semi-finished product 7,
There was a drawback that indentation-like scratches were generated on the surface (top surface) of the cap body 3 to which the electron radiation was adhered.

[Purpose of the invention]

An object of the present invention is to provide a method for manufacturing a cylindrical part for an electron gun, which can prevent indentation-like scratches caused by the adhesion of ironing residue.

[Summary of the invention]

The present invention provides a guide portion that closely fits inside a large-diameter cylindrical portion of the container-shaped component after a blank punched to a predetermined size by punching is formed into a two-stage container-shaped component, and the container-shaped component A punch having an ironing part for ironing the small diameter cylindrical part of the container-shaped part and a die having a hollow ironing hole without a knockout part are used, and the small diameter cylindrical part of the container-shaped part is pressed with the punch by the ironing hole of the die. Then, due to the frictional force between the large-diameter cylindrical part of the container-shaped part and the guide part of the punch, the ironed container-shaped part rises together with the punch, thereby causing the ironing process to occur during the ironing process. Allowing the ironing waste to fall naturally into the ironing hole of the hollowed die, and then cutting off the large diameter cylindrical part from the container-shaped part,
The method is characterized in that a cylindrical part is obtained from a small-diameter cylindrical part that has been ironed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 4 and 5. This embodiment takes the form of continuous production using a transfer press. First, as shown in FIG. 4a, a blank 20 of a predetermined size is punched out by punching. Next, the blank 20 is subjected to drawing processing as shown in FIG.
Form into. Here, the small diameter cylindrical portion 21a is a portion that becomes the cap body 3 shown in FIG. Next, the small-diameter cylindrical portion 21a is ironed using the ironing press mold structure shown in FIG. 5, and the ironed container-shaped part 22 is formed as shown in FIG. 4c. Although this ironing process is performed in a plurality of steps, for convenience of explanation, the description will be made assuming that the container-shaped component 22 is obtained from the container-shaped component 21 in one step. Thereafter, as shown in FIG. 4D, the large diameter cylindrical part 21b is separated from the container-shaped part 22, and the ironed small diameter cylindrical part 22a is formed as the cap body 3.

Next, the structure of the press mold for ironing shown in FIG. 5 will be explained. On the die holder 30 there is a hole 3 for squeezing the small diameter cylindrical part 21a of the container-shaped part 21.
A die 31 on which 1a is formed is fixed.
A knockout is not provided in the straining hole 31a, and the straining hole 31a is hollow. A transfer slide 33 having fingers 32 is provided on the die 31 in a manner similar to the prior art so as to be able to slide back and forth between adjacent processes. Also, the above-mentioned training hole 31
Punch 35 arranged vertically movably above a
has a squeezing part 35a that applies squeezing to the small diameter cylindrical part 21a of the container-shaped part 21, and a guide part 35b that comes into close contact with the inside of the large-diameter cylindrical part 21b of the container-shaped part 21. The outer diameter of this guide portion 35b, that is, the inner diameter of the large diameter cylindrical portion 21b is the same as that of the die 3.
The inner diameter of the first straining hole 31a is larger than that of the first straining hole 31a.

Therefore, as shown in Fig. 5 a and b, the punch 35
descends and pushes down the container-shaped part 21. As a result, the side wall portion of the small diameter cylindrical portion 21a of the container-shaped part 21 is connected to the ironing hole 31a of the die 31 and the punch 35.
An ironing process is applied to the gaps between the ironing parts 35a to reduce the thickness, and a container-shaped part 22 having a small diameter cylindrical part 22a is formed. Note that this container-shaped part 22 is received on the die 31 by a stepped portion between the large diameter cylindrical portion 21b and the small diameter cylindrical portion 22a. Subsequently, the punch 35 is raised as shown in c and d of the figure. At this time, the container-shaped part 22
Since the guide portion 35b of the punch 35 is in close contact with the inside of the large diameter cylindrical portion 21b, the large diameter cylindrical portion 2
Due to the frictional force between 1b and the guide portion 35b, the container-shaped part 22 rises from inside the die 31 together with the punch 35, and is gripped by the fingers 32.

In this way, since the ironing hole 31a of the die 31 is hollowed out, the ironing waste can be inserted into the ironing hole 31.
It falls naturally from point a, and there is no contact with the surface of the cap body 3 to which the electron emitting material is adhered, and the occurrence of indentation-like scratches is completely prevented.

Next, although not directly related to the gist of the present invention, a transfer press for manufacturing drawn parts by continuously and automatically performing drawing press processing will be described.

Conventional transfer presses punch out a single blank at a blanking station, grip it with a pair of fingers, transfer it, and process it continuously. Regardless of the size of the product, it can be processed with one stroke of the press ram. The drawback was that only one product could be processed.

Therefore, a transfer press that can simultaneously process a plurality of the same product or different types of products with one rotation of the press machine will be described below.

FIG. 6 is a front view showing the mechanism of the blanking station of the transfer press. A plunger cam 41 is fixed to a vertical shaft 40 that rotates in synchronization with a gate cam (not shown) that stops the ram for a certain period of time at each of the vertical dead centers. Therefore, as the vertical shaft 40 rotates, the plunger cam 41 also rotates, and the rotation of the plunger cam 41 causes the plunger 42 to move up and down via the lever 43. Then, a plurality of blanks are punched out from the coil material 47 using a plurality of blanking punches 45 fixed to a blanking holder 44 connected to the plunger 42 and a blanking die 46. The punched blanks are raised from within the blanking die 46 at a knockout 48, and are simultaneously gripped and transported by fingers (not shown), and a plurality of blanks are processed simultaneously and continuously in the next step.

In this way, two identical parts can be produced with one stroke of the press machine, that is, a production capacity at least twice that of the conventional machine can be obtained, and press processing costs can be reduced.
In addition, since it is possible to simultaneously process different types of parts, mold manufacturing costs can be reduced, and mold switching work can also be omitted, increasing the operating rate.

Further, although not directly related to the gist of the present invention, a method for forming the roundness of a cylindrical part for an electron gun will be described.

The conventional roundness forming method for cylindrical parts for electron guns is
Generally, ironing is performed using a cylindrical punch. However, in deep-drawn cylindrical parts, non-uniformity of wall thickness occurs on the circumference, making it difficult to achieve uniform ironing, which has the disadvantage of causing a decrease in roundness accuracy.

Therefore, a method for forming the roundness of a cylindrical part for an electron gun that can improve the roundness and reduce processing force will be described below.

As shown in FIG. 7, the punch 50 has a polygonal shape. In this example, it is formed into a 36-sided shape. FIG. 8 shows a state in which ironing is performed using the punch 50. The cylindrical part 51 is ironed at each apex corner of the punch 50, and deformed regions 52 are generated at each position on the circumference, and the roundness shape after processing becomes a wavy shape as shown in FIG. In addition, in FIG. 8, 53 indicates a die.

In this way, the cylindrical part 51 before ironing is partially ironed by the polygonal punch 50.
The roundness can be improved because fluctuations in the amount of ironing due to non-uniform circumferential thickness of the polygonal punch 50 are reduced and a wedge effect is produced by receiving compressive force at the apex portion of the polygonal punch 50. Furthermore, since the ironing process is performed partially in the circumferential direction, the ironing load can be reduced.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, after a blank punched to a predetermined size by punching is formed into a two-stage container-shaped part, Using a punch that has a guide part that comes into close contact with the container-shaped part and an ironing part that irons the small-diameter cylindrical part of the container-shaped part, and a die that does not have a knock-out part and has a hollow ironing hole, the punch can remove the container-shaped part. The small-diameter cylindrical part of is pressed into the ironing hole of the die, and then the ironed container-shaped part rises together with the punch, thereby removing the ironing residue generated during the ironing process into the hollowed ironing hole of the die. Since the cylindrical parts are allowed to fall naturally, there is no chance of the top surface of the cylindrical parts coming into contact with the scrubbing residue, and continuous production can be carried out using a transfer press type without creating indentation-like scratches on the top surfaces of the cylindrical parts. Therefore, the time required to inspect whether or not an indentation-like flaw has occurred can be omitted. In particular, when the cylindrical part is a cathode cap, the cathode cap is a minute part with an inner diameter of 1.6 mm and a height of about 0.65 mm, so a large amount of inspection is required to check for the occurrence of indentations. Inspection time can be omitted, and the effect is significant.

In addition, the blanks are punched to a predetermined size by punching and formed into two-stage container-shaped parts, and the large-diameter cylindrical part is finally separated and used as scrap. Capable of gripping large-diameter cylindrical parts, improving reliability of conveyance and reducing the rotation speed of conventional presses to 60 SPM.
It is possible to achieve approximately twice the speed of 110SPM.

Furthermore, since there is no need for a knock-out, there is no need to attach or remove the knock-out when changing molds, and the time for changing molds can be significantly shortened.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the indirectly heated cathode structure, Figure 2a,
b, c are process diagrams showing the conventional cap body manufacturing process; Fig. 3 a, b, c, d are cross-sectional views showing the operating state of ironing using the conventional mold structure; Fig. 4 a, b,
c, d are process diagrams showing an example of the manufacturing process of a cylindrical part according to the present invention; FIGS. Figure 6 is a front view showing the mechanism of the blanking station of the Transfer Press, Figure 7 is a sectional view of the punch, Figure 8 is an enlarged view of the main part showing the forming state, and Figure 9 is the punch of Figure 7. It is a hole shape diagram of the obtained product. 3... Cap body, 21... Container-shaped part, 21a...
Small diameter cylindrical part, 21b... Large diameter cylindrical part, 22... Container-shaped part, 31... Dice, 31a... Ironing hole, 35... Punch, 35a... Ironing part, 35
b...Guide section.

Claims (1)

[Claims] 1. After forming a blank of a predetermined size into a two-stage container-shaped part, an ironing part is formed to apply ironing to the guide part that tightly contacts the inside of the large-diameter cylindrical part of this container-shaped part and the small-diameter cylindrical part of the container-shaped part. Using a punch having a punch and a die having a hollow ironing hole without a knockout part, press the small diameter cylindrical part of the container-shaped part into the ironing hole of the die with the punch, and then press the small diameter cylindrical part of the container-shaped part into the ironing hole of the die. Due to the frictional force between the diameter cylindrical part and the guide part of the punch, the ironed container-shaped part rises together with the punch, and thereby the ironing residue generated during the ironing process is removed from the hollowed die. A method for manufacturing a cylindrical part for an electron gun, comprising allowing the part to naturally fall into a straining hole, and then separating a large-diameter cylindrical part from the container-shaped part to form a cylindrical part from the small-diameter cylindrical part.