JP3236175B2 - Flange for vacuum duct - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum duct flange provided at a connection portion of a vacuum duct, for example, in an accelerator for forming a collision type electron ring or a radiation light source ring.

[0002]

2. Description of the Prior Art As shown in FIG.
The knife edge 3 is formed facing the opposite surface of the flange main body 2 provided integrally with the
A stepped portion 4 is formed on the inner peripheral side of the blade, and a ring-shaped gasket 5 is inserted between the knife edges 3 to tighten the fastening bolts 7 attached to the bolt holes 6 on the outer periphery of the flange. And two vacuum ducts 1 were connected.

[0003]

However, the above-mentioned flange is tightened by tightening the fastening bolt 7 from the state before the tightening shown in FIG. 6 to reduce the gap α between the outer peripheral surface of the flange body 2 from 1 mm to 0.3 to 0.5 mm. By doing so, the knife edge 3 is cut into the gasket 5 and sealed. However, the gap β between the steps 4 is 2.7 to 2.9 mm from 3.4 mm before tightening.
However, the gap β is still large.

This vacuum duct is made of an aluminum alloy or stainless steel, and electrons or protons circulate in a lump (bunch) inside. When viewed from a fixed point of the vacuum duct, the vacuum duct receives a high-frequency electric field fluctuation. I have. If the inner wall of the vacuum duct is not smooth, a high-frequency electromagnetic field is generated when electrons or protons pass. This electromagnetic field causes the following problems. (1) The beam loses energy and the chamber and flange are heated. (2) An accelerating voltage is required to make up for energy loss. (3) causing beam instability.

Therefore, in order to fill the gap β, FIG.
As shown in FIG. 7, a spacer 8 may be attached to one of the steps 5 with screws 9. However, the spacer 8 cannot completely fill the gap β, leaving a gap β ′ of 0.7 to 0.9 mm, which has an adverse effect. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a flange for a vacuum duct in which an inner surface of a duct of a connecting portion is formed smoothly and an electromagnetic field is not generated.

[0006]

In order to solve the above-mentioned problems, a first means is that a flange body is integrally formed on an outer peripheral portion of a cylindrical portion continuous with a vacuum duct, and a flange body is formed on an opposing surface of the flange body. Annular edges that press against a ring-shaped gasket interposed between the main bodies are respectively protruded, and a gap step is formed on the inner peripheral side of the flange main body, a gap space is opened between the cylinders, and an outer peripheral part is formed. In the flange for a vacuum duct for fastening two flange bodies by a plurality of fasteners connected to the flange, an insertion tube whose inner surface is continuous with the inner surface of the vacuum duct is formed at the end of the cylindrical portion of one of the flanges by opening the gap space. are made to protrude part, the end portion of the cylindrical portion of the other flange, constituting then the bayonet forming said
In both cases, the inner surface of the cylinder of one flange and the inner surface of the other
By connecting the flange body to a thickness that can be bent by the fastener, the fastener is tightened, and the insertion tube is
The flange body is flexed while being in close contact with the receiving step.
The edge is configured to cut into the gasket
It was done .

[0007]

[0008]

According to the first means, the distal end of the insertion tube is fitted to the receiving step, and the flange body is tightened and bent by the fastener, so that the insertion tube and the receiving step are brought into close contact. At the same time, the edge is pressed into contact with the gasket and double-sealed to improve the sealing performance. Therefore, the inner surface of the duct of the connection portion can be formed smoothly, and the occurrence of an electromagnetic field can be prevented, so that the trouble caused by the electromagnetic field can be prevented.

[0009]

[0010]

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a vacuum duct flange according to the present invention will be described below with reference to FIGS. The ends of the vacuum ducts 11A and 11B are provided with flanges 13A and 13B integrally connected to each other via a joint portion 12, and the flanges 13A and 13B
A, 11B, and cylindrical portions 14A, 14B,
A, 14B and flange bodies 15A, 15B integrally formed on the outer periphery of the distal end portion.
5B, connecting holes 15a formed at regular intervals in the outer peripheral portion of
A fastening bolt (fastener) 16 is mounted on 15b.

Edges 17A and 17B are provided on the inner peripheral portions of the connection holes 15a and 15b in the flange main bodies 15A and 15B so as to protrude along the circumferential direction.
The gasket 18 is pressed against the side surface of the ring-shaped gasket 18 and bites into the ring-shaped gasket 18 to secure the sealing property. In addition, the cylindrical portions 14A and 14B and the flange body 15
A gap steps 19A, 19B facing each other are formed on the inner peripheral sides of the flanges 13A, 13B.
A gap space 20 is formed between the inner peripheral portions of the gap.

The cylindrical portion 14 of the one flange 13A
A thin-walled insertion tube 21 whose inner surface is continuous with the inner surface of the vacuum duct 11A protrudes from the opening surface of the gap space 20 at the end of A, and an inner surface is formed at the end of the cylindrical portion 14B of the other flange 13B. A thick receiving cylinder 22 continuous with the inner surface of the vacuum duct 11B is projected from the opening surface of the gap space 20,
A receiving step portion 22 a into which the distal end of the insertion tube 21 is inserted is formed on the inner surface of the distal end portion of the receiving tube 22. Further, the thickness T of the flange main bodies 15A and 15B is set to a thickness that can be bent to the side approaching each other by the fastening bolt 16, whereby the fastening bolt 16 is tightened to bend the flange main bodies 15A and 15B. The edges 17A and 17B can be cut into the gasket 18 and sealed. At the base end of the receiving cylinder 22 of the flange main body 15B, air vent holes 23 communicating the gap space 20 and the cylindrical part 14B are formed at a plurality of locations.

The flanges 13A and 13B and the vacuum ducts 11A and 11B are formed as separate members. That is, annular insertion portions 24 are respectively provided at the ends of the vacuum duct 11A and the cylindrical portion 14B so as to protrude along the inner peripheral surface, and the annular receiving portions 24 are respectively fitted to the vacuum duct 11B and the cylindrical portion 14A. It is of a plug-in type with a step 25 formed. A welding groove 26 having a predetermined groove angle γ is formed on the outer periphery thereof, and is joined by welding 27. The ratio between the thickness and the depth of each of the annular insertion portion 24 and the annular receiving portion 25 is set to, for example, the same t. As a result, compared to the integral type of duct and flange,
The flange can be independently machined with high accuracy, and the contact area can be increased by the plug-in type to improve the sealing performance.

FIG. 3 shows the results of a helium leak test after the short pipe having the flanges 13A and 13B having the above-described structure was evacuated by a vacuum pump. According to the above test, no leakage of helium was confirmed, and 1 × 10 ⁻¹⁰ torr · l
A leak rate of / sec or less was confirmed. According to the first embodiment, the distal end of the insertion tube 21 is connected to the receiving step 22a of the receiving tube 22.
And the flange bodies 15A, 15B are tightened by the fastening bolts 16 so that the flanges 13A, 13B are pressed against the opening surface of the gap space 20 between the flanges 13A, 13B without forming a gap. Is formed, and the edge edges 17A, 17B are formed by the gasket 18 by bending of the flange bodies 15A, 15B.
And the sealing property can be secured. Therefore, the inner surfaces of the vacuum ducts 11A and 11B of the connection portion can be formed smoothly, and the generation of an electromagnetic field can be prevented, thereby preventing the trouble caused by the electromagnetic field .

Next, a second embodiment of the flange for a vacuum duct will be described with reference to FIGS. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 5, the gap step 1 of one flange 13A is provided.
9A, a contact member 42 whose outer peripheral portion is fixed to the flange body 15A by a plurality of fixing screws (fixing tools) 41 is provided. This contact member 42 is provided as shown in FIG.
As shown in (a) , a plate material having conductivity and elasticity (springiness) is formed into a ring shape, and a plurality of screw holes 42 are formed in the outer peripheral portion.
a is formed, and strip-shaped cuts 42b are formed at predetermined angles in the radial direction from the inner peripheral edge, and as shown in FIG. 5 (b) , each strip 42c is bent circularly from the inside to the outside . As shown in FIG. 5 (b) , it is formed in a circular cross section larger than the opening of the gap space 20,
The inner peripheral portion is bent along the inner peripheral surface of the cylindrical portion 14A, and the bent strip 42c is brought into contact with the end surface of the cylindrical portion 14B of the other flange 13B to close the opening of the gap space 20. It is composed of

Therefore, the gap space 20 is formed in the vacuum duct 11 through the notch 42b of the contact member 42.
Since the communication with the insides of the contact members A and 11B eliminates the need for an air vent hole, the contact member 42 has resilience against collapse in the flange axial direction, and the edges 17A and 17B.
The opening of the gap space 20 is reliably closed by following the opening of the gap space 20 that fluctuates due to the pressure contact of the gasket 18 with the gasket 18, and the inner surface shape of the connection portion of the flanges 13A and 13B has geometric continuity. Thus, it is possible to prevent the generation of the electromagnetic field and prevent the trouble caused by the electromagnetic field.

[0018]

As described above, according to the first aspect of the present invention, the distal end portion of the insertion tube is fitted into the receiving step portion, and the flange body is tightened and bent by the fastener,
The insertion tube and the receiving step are brought into close contact with each other, and the edge is pressed against the gasket, so that the sealing is double-sealed and the sealing performance is improved. Therefore, the inner surface of the duct of the connection portion can be formed smoothly, and the occurrence of an electromagnetic field can be prevented, so that the trouble caused by the electromagnetic field can be prevented.

[0019]

[0020]

[Brief description of the drawings]

FIG. 1 is an enlarged partial sectional view showing a first embodiment of a flange for a vacuum duct according to the present invention.

FIG. 2 is an enlarged view of a portion A shown in FIG.

FIG. 3 is a graph showing a result of a leak test of the vacuum duct flange.

FIG. 4 is an enlarged partial sectional view showing a third embodiment of a flange for a vacuum duct according to the present invention.

5 (a) and 5 (b) are semi-front views showing a procedure for manufacturing a contact member of the vacuum duct flange, and FIG. 5 (c) is a partially enlarged sectional view of the contact member.

FIG. 6 is an enlarged partial sectional view showing a conventional vacuum duct flange.

FIG. 7 is an enlarged partial sectional view showing another conventional vacuum duct flange.

[Explanation of symbols]

11A, 11B Vacuum duct 12 Joint 13A, 13B Flange 14A, 14B Tube 15A, 15B Flange body 15a, 15b Connection hole 16 Fastening bolt (fastener) 17A, 17B Edge 18 Gasket 19A, 19B Gap step 20 Gap space DESCRIPTION OF SYMBOLS 21 Inserting cylinder 22 Receiving cylinder 22a Receiving step part 23 Air vent hole 24 Annular inserting part 25 Annular receiving step part 26 Groove part 41 Fixing screw 42 Contact member

Continuation of the front page (56) References JP-A-2-210800 (JP, A) JP-A-5-283197 (JP, A) JP-A-7-111197 (JP, A) JP-A-5-66899 (JP) U.S. Pat. No. 6,28,476 (JP, U) U.S. Pat. No. 6,656,598 (JP, U) U.S. Pat. No. 5,66,900 (JP, U) U.S. Pat. (US, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H05H 7/14 H05H 13/04

Claims (1)

(57) [Claims] 1. A flange body is integrally formed on an outer peripheral portion of a cylindrical portion connected to a vacuum duct, and annular edges which are in pressure contact with a ring-shaped gasket interposed between the flange bodies are formed on opposite surfaces of the flange body. While being protruded,
A step for a gap is formed on the inner peripheral side of the flange body, a gap space is opened between the cylindrical parts, and a flange for a vacuum duct for fastening two flange bodies by a plurality of fasteners connected to the outer peripheral part. At the end of the cylindrical portion of the flange, an insertion tube whose inner surface is continuous with the inner surface of the vacuum duct projects into the opening of the gap space, and at the end of the cylindrical portion of the other flange, the tip of the insertion tube has Forming a receiving step portion that is closely fitted inside so as to form a plug-in type, and connecting the inner surface of the cylindrical portion of one flange and the inner surface of the other cylindrical portion, and forming the flange main body to a thickness that can be bent by a fastener. A flange for a vacuum duct, wherein a fastener is tightened to bend the flange main body so that an edge bites into the gasket.