JPH07164041A - Method for drawing duct and device therefor - Google Patents

Abstract

PURPOSE:To provide a drawing method for a duct by which the inside surface with reduced gas release and light stimulating release by radiated light irradiation under high vacuum can be formed, a drawing device for executing the method and a vacuum duct which is produced by the device. CONSTITUTION:A material to be drawn 4 is drawn and simultaneously the inside surface of the drawn duct is ground using a die 3 and a plug 1. The drawing device consists of the die 3 which is a taper holed tool and the plug 1 which is inserted in the taper hole of the die 3 and provided with a grinding surface 2 on its outer circumference. A beam duct is produced by drawing the duct using the drawing device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drawing method and apparatus for drawing a duct, and more particularly to a drawing method and apparatus for a duct used as a vacuum container.

[0002]

2. Description of the Related Art As an example of a duct manufactured by a drawing method, a conventional beam duct of an electron or positron storage ring which is a kind of charged particle accelerator will be described as a conventional technique. Conventional beam ducts are reported in Institute of High Energy Physics, No. 81-2 (1981), pp. 72-7.
As discussed on page 3, it consists of a very elongated, annular container with an ultrahigh vacuum inside. The beam duct is installed inside a dipole, quadrupole, and hexapole magnet for controlling electrons or positrons. Electrons or positrons are accelerated or accumulated inside the beam duct, but in these magnets, the electrons or positrons receive bremsstrahlung and generate radiated light. Light other than the emitted light that is extracted from the storage ring for use illuminates the inner wall of the beam duct, causing outgassing from the beam duct surface, called photostimulated desorption. Regarding photostimulation desorption, for example, literature vacuum,
Volume 33, number 7 (1983), pages 397 to 406 (Vacuum, volume33, number7 (1983) p
age 397 to 406). Outgassing caused by photostimulated desorption increases the pressure inside the beam duct. As a result, the gas and electrons or positrons collide with each other to reduce the number of accumulated electrons, which causes a problem that the collision frequency is reduced in the collider and the radiance is reduced in the case of utilizing synchrotron radiation. In order to solve this problem, conventionally, the inner surface of the beam duct has been chemically treated. For example, as an example of chemical treatment, reference is made to: Vacuum, Volume 3
8, number 8-10 (1988), pages 933 to 936 (Vacuum, volume38, number8-10 (1988) pag
e 933 to 936). Attempts have been made to clean the duct surface with these treatments to reduce photostimulated desorption.

[0003]

In the vacuum container such as the beam duct of the charged particle accelerator of the above-mentioned prior art, friction between the material and a tool such as a plug is reduced at the time of extrusion processing for forming a duct from a material such as a billet. Since a lubricant may be used for the purpose, this lubricant may form a contaminated layer on the inner surface of the duct, in which molecules causing gas release or photostimulation desorption are retained. Further, when a duct is formed by hot extrusion or the like, the surface formed at a high temperature may react with air or impurities to form a contaminated layer serving as a gas emission source. Chemical treatment of the surface for the purpose of reducing gas emission and photostimulated desorption from these contaminated layers requires that the surface chemical treatment method be changed depending on the material, or that the chemical agent is used. ,
Problems such as roughening the surface at the same time as removing the gas release layer.Furthermore, since chemicals are used, facilities such as post-treatment cleaning equipment and environmental pollution prevention equipment are required. There was a problem that the scale became large. In addition, there is also a problem that the surface chemical treatment causes a compound layer which becomes a gas emission source to be generated on the surface of the beam duct.

An object of the present invention is to perform a duct drawing method capable of forming an inner surface for reducing gas emission and photostimulated desorption due to irradiation of radiant light under a high vacuum, and a drawing apparatus for performing the method. It is to provide a vacuum duct made by a drawing machine.

[0005]

SUMMARY OF THE INVENTION In the duct drawing method for manufacturing a duct by drawing a drawn material using a die and a plug, the above-mentioned object is to grind the inner surface of the duct simultaneously with the drawing of the drawn material. It is achieved by

It is desirable to supply gas during the drawing of the drawn material and the grinding of the inner surface of the duct.

The gas is preferably an inert gas.

The above-mentioned object is to provide a duct drawing apparatus provided with a die having a tapered hole in a tool and a plug inserted into the tapered hole of the die, wherein grinding means is provided on the outer peripheral surface of the plug. Achieved by

It is desirable that the vacuum duct has a structure in which flanges are provided at both ends of the duct manufactured by the duct drawing apparatus.

It is desirable to use the vacuum duct as the beam duct of the charged particle accelerator.

[0011]

[Function] By grinding the inner surface of the duct at the same time as the drawing of the drawn material, the surface contamination layer which is formed during the drawing and serves as a gas discharge source such as gas discharge from the vacuum container and photostimulated desorption due to irradiation of radiant light is removed. Can be removed.

Further, the surface chemical treatment becomes unnecessary and the equipment required therefor becomes unnecessary.

Further, there is no fear that the surface will be roughened by the chemical treatment and a compound layer which will be a gas emission source will be formed.

Further, by providing flanges at both ends of the duct to form a vacuum container, a beam duct of a charged particle accelerator can be obtained which can reduce photostimulation and desorption due to gas emission and irradiation of radiant light.

[0015]

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

First, the apparatus according to this embodiment will be described.

FIG. 1 is an explanatory view for explaining a drawing apparatus according to an embodiment of the present invention.

As shown in the figure, it comprises a die 3, a plug 1, a plug supporting device 5 for fixing the plug, and a pulling device 6 for pulling the pulling member 4 forward by a pulling force. A duct used as a vacuum container and a beam duct for accelerating and accumulating electrons and positrons are usually formed into a desired cross-sectional shape by drawing after extrusion. Duct material is usually stainless steel,
Aluminum alloy, copper, etc.

First, a general drawing method will be described.

FIG. 2 is a partial sectional view for explaining a general drawing method.

As shown in the figure, the drawn material 4-1 (material before drawing) manufactured by extrusion processing is the die 3
And the plug 1 is inserted inside the drawing material. The plug 1 is fixed by a plug support device 5. The drawing material inserted into the die 3 is drawn rightward in the drawing by the pulling device 6 shown in FIG. 1, and undergoes plastic deformation when passing through a space determined by the relative positional relationship between the die 3 and the plug 1. Molded and drawn material 4-2
(Material after drawing).

Next, the drawing method according to this embodiment will be described.

One of the features of the present invention is that the inner surface of the drawn material is ground at the same time as the drawing, and the plug used for the grinding will be described.

FIG. 3 is a sectional view of a plug according to an embodiment of the present invention.

As shown in the figure, a part of the outer peripheral surface of the plug 1 is in contact with the inner surface of the duct (not shown) and serves to adjust the inner surface shape of the drawn material. The outer peripheral surface of the plug 1 is a ground surface 2 that is in contact with the drawn material and has projections and irregularities on the surface for grinding the inner surface of the drawn material.

FIG. 4 is a partially enlarged sectional view of the ground surface of the plug shown in FIG.

A grinding layer 7 containing diamond particles 8 is formed on the surface of the plug 1. This grinding layer 7 is
Diamond particles are fixed on the nickel film by electrodeposition or the like. When the duct that serves as a vacuum container is drawn by using such a plug 1, the contaminated layer formed on the inner surface of the duct by the plug at the time of the extruding process can be removed by grinding at the same time when the cross-sectional shape is formed. It will be possible. As a result, it is possible to reduce the gas emission from the duct and the photostimulation detachment due to the irradiation of radiant light. The thickness of such a contaminated layer is several hundred μm.
Since it is considered as follows, it can be sufficiently removed by diamond particles.

FIG. 5 is a partially enlarged sectional view of another plug grinding surface of FIG.

FIG. 6 is a partial perspective view of FIG.

By making the surface of the plug 1 the uneven file surface 9, it is possible to remove the contamination layer by grinding the inner surface of the drawn material as in the above-mentioned embodiment.

In the above embodiment, the examples of the diamond particles and the rasp surface of the ground surface of the plug have been described, but the purpose is to grind the inner surface of the drawn material, and the plug surface roughness is more than the surface roughness of the drawn material. If it is also rough, it can be another grinding surface.

FIG. 7 is a table showing the experimental results of the surface grinding of the present invention and the conventional electrolytic polishing.

This figure shows the photostimulated desorption when oxygen-free copper subjected to two kinds of surface treatments was irradiated with radiant light. The horizontal axis is the integrated value of the radiant light irradiation amount, which is a value equivalent to the total irradiation photon number. The vertical axis is called the yield and represents the number of molecules desorbed by one photon, which is a value corresponding to the amount of gas released. The lower the yield value, the less the light stimulated desorption from the vacuum container, which means that it is a high performance vacuum duct or a high performance beam duct. When the surface grinding is performed rather than the electrolytic polishing treatment, the yield value is lower in the entire irradiation region from the start of irradiation of the radiant light. This indicates that the method of grinding the surface is more effective than the electrolytic polishing in removing the contaminated layer which is a gas emission source.

Next, a method of introducing gas into the duct during drawing will be described.

FIG. 8 is a sectional view for explaining a drawing method according to another embodiment of the present invention.

In the drawing method shown in this figure, the plug 1 is supported by the plug support device 5 is a ball-drawing type.
A gas introduction path 11 is provided inside the plug 1 and the plug support device 5.
To supply gas from the fixed side of the plug supporting device 5,
This is an example of discharging gas from the tip of the plug 1. The discharged gas fills the interior of the drawing material (not shown). By sealing the tip of the drawing material in the drawing direction, the filled gas passes through the gap between the grinding surface 2 and the inner surface of the drawing material and flows toward the plug support device 5. When the gas does not flow, the grinding surface 2 on the surface of the plug 1 grinds the inner surface of the drawn material, so that the inner surface temperature of the drawn material rises, and an oxide or the like which causes a thermal reaction with air or moisture inside the duct and becomes a gas release source. May generate. However, by flowing an inert gas such as, for example, argon, the gas can shield the ground clean surface, so that it does not form the oxides mentioned above. Further, by flowing the gas, the plug 1 and the drawn material are cooled, so that it is possible to prevent variations in the surface to be ground due to temperature changes.

FIG. 9 is a sectional view for explaining a drawing method according to another embodiment of the present invention.

The pulling method shown in this figure is a floating plug pulling type in which the plug 1 is not supported by the plug supporting device 5, and a pulling device (not shown) for pulling the pulling material 4-2 (after-drawing material) in the pulling direction. From this pulling device side, an inert gas such as argon is supplied to the inside of the drawing material 4-2 (material after drawing). The supplied inert gas flows to the left in the drawing through the gap between the plug 1 and the drawing material 4, as in the embodiment shown in FIG. By supplying the inert gas, it is possible to prevent the surface to be ground of the drawn material from being oxidized.

In each of the embodiments for supplying the above-mentioned gas, an inert gas was used as the gas, but it is of course possible to introduce any elemental gas in order to form a desired film on the surface to be ground. . For example, introduction of oxygen gas may be considered in order to intentionally form a stable oxide film on the surface to be ground.

FIG. 10 is a sectional view for explaining the drawing process of various ducts according to the embodiment of the present invention.

As shown in the figure, an elliptical duct or a rectangular duct is extruded from a circular duct by hot or cold extrusion, and then the duct inner surface and the duct inner surface are simultaneously ground.

FIG. 11 is a perspective view showing the structure of the vacuum duct according to the embodiment of the present invention.

After the duct manufacturing process as described above, necessary branch pipes and flanges are attached by welding or the like to complete a beam duct used as a vacuum container. The inner surface of the beam duct manufactured in this way is subjected to grinding processing, and it is possible to reduce gas emission such as photostimulation desorption,
It is possible to obtain a high-performance charged particle accelerator that suppresses the reduction of charged particles in an accelerator such as a storage ring. Further, the surface chemical treatment becomes unnecessary, and the equipment required for it becomes unnecessary. Furthermore, there is no risk of roughening the surface or forming a compound layer which becomes a gas emission source by the chemical treatment.

In the above embodiments, the duct inner surface grinding method at the time of drawing is described. Of course, even in the case of extrusion, the grinding surface is provided on the outer peripheral surface of the plug as in the present embodiment, and the duct at the time of extrusion is formed. It is possible to perform internal grinding.

[0045]

According to the present invention, the inner surface of the duct is ground at the same time as the drawing of the drawn material, so that the gas formed during the drawing is released under high vacuum, and the gas such as the photostimulated desorption due to the irradiation of radiant light is emitted. It is possible to remove the surface contamination layer which is the emission source.

By providing flanges at both ends of the above duct to form a vacuum container, a beam duct of a charged particle accelerator can be obtained which can reduce photostimulation desorption due to gas emission and irradiation of radiant light.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating a drawing processing apparatus according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view illustrating a general drawing method.

FIG. 3 is a sectional view of a plug according to an embodiment of the present invention.

FIG. 4 is a partially enlarged cross-sectional view of the plug grinding surface of FIG.

5 is a partially enlarged sectional view of another plug grinding surface of FIG.

FIG. 6 is a partial perspective view of FIG.

FIG. 7 is a chart showing experimental results of surface grinding of the present invention and conventional electrolytic polishing.

FIG. 8 is a cross-sectional view illustrating a drawing method according to another embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating a drawing method according to another embodiment of the present invention.

FIG. 10 is a cross-sectional view illustrating a drawing process of various ducts according to the embodiment of this invention.

FIG. 11 is a perspective view showing a configuration of a vacuum duct according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plug 2 Grinding surface 3 Die 4 Drawing material 4-1 Drawing material before drawing 4-2 Drawing material after drawing 5 Plug support device 6 Pulling device 7 Grinding layer 8 Diamond particle 9 Rasp surface 10 Flange 11 Gas introduction path

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mamoru Katane 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Hiroaki Sakuraba, 3-chome, Saiwaicho, Hitachi-shi, Ibaraki 1st-1 Hitachi Ltd. Hitachi factory (72) Inventor Shiro Matsuzaki 3-1-1 1-1 Saiwaicho, Hitachi City, Ibaraki Hitachi Ltd. Hitachi factory

Claims (8)

[Claims] 1. A duct drawing method for manufacturing a duct by drawing a drawn material using a die and a plug, wherein the inner surface of the duct is ground simultaneously with the drawing of the drawn material. Processing method. 2. The duct drawing method according to claim 1, wherein a gas is supplied when the drawing material is drawn and the inner surface of the duct is ground. 3. The duct drawing method according to claim 2, wherein the gas is an inert gas. 4. A duct drawing apparatus provided with a die having a tapered hole in a tool and a plug inserted into the tapered hole of the die, wherein grinding means is provided on an outer peripheral surface of the plug. Equipment for drawing ducts. 5. The duct drawing apparatus according to claim 4, further comprising means for supplying gas to the plug. 6. The duct drawing apparatus according to claim 4, further comprising means for supplying an inert gas to the plug. 7. A vacuum duct, characterized in that flanges are provided at both ends of the duct manufactured by the duct drawing apparatus according to any one of claims 4 to 6. 8. A beam duct for a charged particle accelerator, wherein the vacuum duct according to claim 7 is used.