JPH045807Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a vacuum flange tightening clamp.

(Prior Art) In the future, the focus of vacuum particle accelerators will be to increase the intensity and energy of accelerated beams, and at the same time, residual radioactivity will accumulate throughout the device and the air dose will also increase. Under such conditions, there are limits to what humans can do to perform maintenance, improvement, and other work, and remote control or automation is required.

What would be a simple task if done by a human becomes a considerably complex mechanism if done by remote control or automated equipment.

There are two types of vacuum flange tightening clamps currently available on the market: band type and chain type. These clamps are tightened with one or two bolts.

The band type uses an elastomer gasket to seal the flange, and the chain type uses specially shaped Al,
A soft metal gasket such as Cu is used.

Here, the structures of NW flanges and clamp chains as typical vacuum flanges and tightening clamps are shown in Figures 1 and 2. FIG. 1 is a diagrammatic plan view showing a part of an example of use, and FIG. 2 is a diagrammatic cross-sectional view thereof. As shown in FIG. 1, a clamp chain surrounds the outer diameter side of the flange 1.
The clamp chain connects a clamp 2 to another clamp 2 via a stainless steel chain 3 and a shaft 4, forming a chain shape. Two tightening bolts 5 are provided at symmetrical positions on the clamp chain. As shown in Fig. 2, the tapers of the clamp 3 and the flange 1 are at the same angle (20°), and by turning the tightening bolt 5, the clamp 2
The flange 1 enters into the flange 1 and presses against the gasket 6 to form a seal.

(Problem to be solved by the invention) If the angle of the flange matches the angle of the clamp chain, a sufficient seal can be obtained with less tightening bolt torque, but there may be a slight error in the angle of the clamp chain. If there is, only the tip of the clamp 2 contacts, or the tip of the flange 1 hits the back of the tapered part of the clamp 2, so the tightening torque tends to increase, which has the disadvantage of damaging the contact area. .

In addition, when automating the attachment and detachment of flanges, a chain system causes large deformation, and a mechanism for supporting the clamp of the tightening bolt part and the intermediate part is also added, making the structure of the automatic equipment complicated. In addition, since the clamp chain connects the clamps with individual connecting chains, it deforms like a bicycle chain. Therefore, when automating the clamp chain, it is necessary to have a mechanism that not only supports both ends of the clamp halves, but also supports it in the middle. Ta. Furthermore, this type of clamp has a rough pitch, and heating degassing, which requires an ultra-high vacuum, is impossible because the flange is distorted by heating.

Furthermore, in the field of ultra-high vacuum particle accelerators, hadrons or heavy ions are accelerated, and the trend is towards higher beam intensity and enhancement of acceleration energy. These accelerated beams cause losses in some way, activating the accelerator main body, its surroundings, and the laboratory, and the radiation dose increases as the operating time increases. There are limits to what humans can do under these circumstances, and there is a demand for remote control or automated equipment to do the work, and one of these is the ability to easily attach and detach flanges.

(Means for solving the problem) The present invention is a vacuum flange tightening clamp in which a large number of clamps are fixed to a metal strip, and a flange is attached to the side opposite to the side fixed to the metal strip of the clamp. A tapered part that engages with the outer peripheral edge is provided, and a number of clamps fixed to the metal strip are attached by engaging the tapered part with the outer peripheral edge of the flange.
The tapered portion of the clamp is provided with a curvature so that the tapered portion of the clamp makes surface contact with the tapered portion of the flange.

As the metal band plate, a stainless steel band plate is particularly suitable.

If heating and degassing are required to achieve an ultra-high vacuum, such as in an ultra-high vacuum device, distortion of the flange can be eliminated by making the clamps stainless steel and reducing the pitch of the clamps.

The tightening clamp of this invention is a NW with a relatively large outer diameter of 100 mmφ or more that is generally available on the market.
Particularly useful for flanges.

(Function) Since the device of the present invention fixes the clamp to a stainless steel strip, large deformation unlike the clamp chain method is prevented, and automatic operation devices can be easily used.

In addition, due to the error in the taper angle that occurs during flange processing, we provide a curvature in the tapered part of the clamp so that only the tip of the clamp or the tip of the flange does not hit, and so that the middle of the clamp contacts the taper of the flange. As a result, a tight seal is achieved.

Furthermore, if heated degassing is required, strain on the flange can be eliminated by making the clamps stainless steel and reducing the pitch of the clamps.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 Figures 3 and 4 show a clamp for tightening a flange according to the present invention. FIG. 3 shows a plan view when the clamp of the present invention is attached to a flange, and FIG. 4 shows a sectional view thereof. As shown in FIG. 3, the clamp 2 and the tightening clamp 8 are attached to a belt-shaped stainless steel plate 9 having a thickness of 1 to 1.5 mm. The length of the strip plate 9 can be adjusted according to the outer diameter of the flange 1 to increase or decrease the number of clamps 2. The clamp 2 is fixed to the strip plate 9 with a screw 10, and in order to prevent the screw 10 from loosening and the clamp 2 being displaced and not entering the tapered part of the flange 1, a pin 11 is provided on the clamp 2 as a guide, and the strip plate 9 is fixed with a pin 11 as a guide. A guide hole (not shown) is provided in the guide hole, and the pin 11 is fitted into the guide hole. By tightening the tightening clamps 8, 8 with the tightening bolts 5, the clamp 2 tightens the tapered portion of the flange 1.

As shown in Figure 4, the flange 1 has the same 20° angle as the NW type. However, during processing,
Among the many flanges, there will always be some with an error of 20°±α. Due to this slight error, the tapered surface of the flange will not be hit uniformly, so the tightening force will be increased slightly. In addition, in order to prevent the contact part of the stainless steel flange from biting slightly in the case of the aluminum alloy clamp 2, a curvature is provided in the tapered part 13 of the clamp 2, which corresponds to the tapered part 12 of the flange 1, so that the flange 1 and the clamp 2 so that it does not touch only at one point of contact, that is, it makes surface contact. By making the clamp 2 stainless steel and making the installation pitch small as shown in FIG. 3, it is possible to repeatedly heat and degas the device to a temperature of about 300° C. or higher.

Embodiment 2 An example of automation of the tightening clamp of the present invention is shown in FIG. 5. In this case, threaded rods 14 are passed through both the upper and lower sides of the tightening clamp 8, and the upper part from the center of the flange has a right-hand thread, and the lower part has a left-hand thread. The length of the threaded rod 14 is set to be a sufficient distance from the flange 1. When the gear 16 is screwed onto the threaded rod 14 and the left and right threaded rods 14, 14 are simultaneously rotated by the drive mechanism 15, the tightening clamps 8 move up and down, respectively, to tighten the flange 1. When removing the clamp 2, the motor of the drive mechanism 15 is rotated in reverse to loosen the tightening clamp 8, and the clamp 2 is removed from the flange 1. In this way, the flange can be automatically tightened with a simple mechanism. If the device does not need to be heated and degassed, the clamps may be made of aluminum alloy and the number of clamps may be reduced.

(Effects of the invention) Manufacturing costs are low because the tolerance for clamp dimensions is increased and almost any clamp can be used.

Can be reliably sealed with a small tightening torque. Damage to the clamp is almost eliminated and the clamp can be used repeatedly.

When heating and degassing is performed to create an ultra-high vacuum, the flange will not be distorted by heating.

Since it can be easily and reliably attached and detached in a short period of time, the individual exposure dose is reduced during maintenance and improvement work in high radiation dose environments such as vacuum particle accelerators.

Furthermore, since it has a simple structure and the clamp is fixed to a stainless steel band plate, it does not deform unlike a chain type, and the flange attachment/detachment work can be easily remotely controlled or automated.

[Brief explanation of the drawing]

1 is a diagrammatic plan view showing a part of a conventional chain type clamp device, FIG. 2 is a diagrammatic sectional view thereof, FIG. 3 is a diagrammatic plan view showing an example of the clamp of the present invention, and FIG. The figure is a diagrammatic sectional view thereof, and FIG. 5 is a diagrammatic side view showing another example of the clamp of the present invention. 1...Flange, 2...Clamp, 3...Chain, 4...Shaft, 5...Tightening bolt, 6...
... Gasket, 8 ... Tightening clamp, 9 ... Band plate, 10 ... Screw, 11 ... Pin, 12 ... Tapered part of flange 1, 13 ... Taper part of clamp 2, 14 ... Threaded rod , 15... Drive mechanism, 1
6...Screw.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a vacuum flange tightening clamp, a number of clamps are fixed to a metal band plate, and the outer peripheral edge of the flange is attached to the side opposite to the side of the clamp fixed to the metal band plate. A number of clamps fixed to a metal strip plate are installed with the tapered parts engaging the outer peripheral edge of the flange, and the tapered part of the clamp is provided with a curvature so that the tapered part of the clamp A vacuum flange tightening clamp characterized by surface contact with the tapered part. 2 Utility Model Registration In the clamp for tightening a vacuum flange according to claim 1, the clamp has a guide pin on the surface in contact with the metal band plate, a guide hole is provided in the metal band plate to engage with the guide pin, and A vacuum flange tightening clamp in which a guide pin is fitted into the guide hole.