GB2121921A

GB2121921A - Sluice valve

Info

Publication number: GB2121921A
Application number: GB08217358A
Authority: GB
Inventors: Hiroshi Ishii; Hiroshi Morii; Saburo Ishijima
Original assignee: Japan Oxygen Co Ltd; Nippon Sanso Corp
Current assignee: Japan Oxygen Co Ltd; Nippon Sanso Corp
Priority date: 1982-06-15
Filing date: 1982-06-15
Publication date: 1984-01-04
Also published as: GB2121921B

Abstract

A sluice-type valve is adapted to make an air-tight partition, or communication between a vacuum treatment chamber and the atmosphere or a pre-chamber 11 and includes a valve seat member comprising a member of cylindrical shape having therein an opening, a guide rail 18 attached to the inner circumference of the seat member, a valve member 20 movably supported on the guide rail, and means 25, 26, 27 for enabling air-tight engagement of the valve member and the valve seat portion of the seat member. The valve member 20 has a curvature equal to that of the cylindrically shaped member, and the engagement means may comprise a plurality of bellows 25 which are expandible by a compressed gas such as air. Instead of being of cylindrical shape, the member of the valve seat member may be of spherical shape. <IMAGE>

Description

SPECIFICATION Sluice valve arrangement The present invention relates to a sluice valve arrangement, and more particularly to a sluice valve arrangement of the type which is designed to open an opening through which a workpiece is fed into a vacuum chamber, or to close the opening in an air-tight manner so as to treat a workpiece in the vacuum chamber in a hermetically sealed state.

In the treatment of a workpiece under vacuum, for example, in the vacuum drying of workpieces or the vacuum brazing of metals, various sluice valve arrangements have been used to permit easy feeding of workpieces into vacuum chambers, and to provide hermetic closing of the openings through which the workpieces have been supplied into the vacuum chambers, thereby effectively keeping the vacuum chambers in an air-tight state.One typical known example of sluice valve arrangement is designed to be opened or shut between a vacuum chamber and a prechamber which is communicatable therewith so as to reduce the amount of ambient air entering into the vacuum chamber as much as possible, in the case of supplying or discharging a workpiece into or out of the vacuum chamber, In Fig. 1 of the accompanying drawings, there is shown a known sluice valve arrangement 4 (4') disposed between a vacuum chamber 1 arid a prechamber 2 (3) for intercommunicating or shutting off communication therebetween, and closed by a cover 5 (5').

With the arrangement of this type, the vacuum chamber is invariably maintained at a desired pressure. The sluice valve 4 (4') is hermetically closed to render the pressure in the pre-chamber 2 (3) substantially equal to that in the vacuum chamber 1, and then manipulated to put the prechamber 2 (3) in communication with the vacuum chamber 1, while the said pressure is maintained.

Thereafter, feeding or discharging the workpiece 0 into or out of the vacuum chamber 1 is effected.

The sluice valve arrangement 4 (4') should have a passage of a greater sectional area because of the need of feeding the workpiece into both the vacuum chamber 1 and the pre-chamber 2 (3). With this arrangement, it is further required to reduce the space between the valve flanges as much as possible so as to enable the workpiece to be delivered without using any delivery system 6 in the arrangement.

This is the reason why use has been made heretofore of a sluice type valve arrangement employing a flat valve member, as will be understood from. Fig. 2 which shows in more detail the sluice valve arrangement of Fig. 1.

Referring more particularly to Fig. 2, this sluicetype valve arrangement is constructed from a valve box B including a passage F provided on its edge with flanges A and a flat valve member D disposed hermetically in a guide groove C in such a manner that it is vertically or horizontally slidable therein. The passage F is opened and closed by the valve member D driven by a driving mechanism E. The valve box B includes a housing G designed to accommodate the valve member D when the valve is opened, and to maintain the passage F in a hermetic state. The housing G is maintained under vacuum as mentioned above, and receives atmospheric pressure on its outer wall. Thus the outer wall of the housing G should be constructed to resist atmospheric pressure, to which end it is usually reinforced with a latticed structure H, as illustrated.

However, when the structure H is attached to the valve box B as by welding, there is a possibility that the valve box may be distorted and deformed due to heat.

When the passage F is closed by the valve member D, and the pre-exhaust chamber is brought to atmospheric pressure, a load is applied on the valve member D. Due to its flatness, the valve member D may be distorted by a vacuum load applied theron, rendering its opening or closing difficult and its hermetic closing even more difficult. It has been found that as the diameter of the passage F increases, such problems are more likely to arise.

The present invention has for its main object to provide a solution to the aforesaid problems, by providing a novel sluice valve arrangement which is capable of making a hermetic partition between a vacuum chamber and the atmosphere or a prechamber when the valve is closed.

To this end, the present invention consists in a valve arrangement adapted to open or close an opening leading to a vacuum chamber, including a valve seat member comprising a member of cylindrical or spherical shape having an opening therein, a guide rail secured to the inner circumference of said valve seat member, a valve member movably supported on said guide rail, and means for enabling air-tight engagement of said valve member with the valve seat portion of said seat member.

In order that the invention may be more readily understood, reference will now be made to the accompanying drawings, in which: Fig. 1 is a side elevation of the prior art vacuum treatment system of which the sluice valve arrangement has already been described, Fig. 2 is a perspective view of the prior art sluice valve arrangement used with the system of Fig. 1, Fig. 3 is a perspective view of one embodiment of a pre-exhaust chamber to be provided with a sluice valve arrangement constructed in accordance with the present invention, Fig. 4 is a perspective view of another embodiment of a pre-exhaust chamber to be provided with a sluice valve arrangement constructed according to the present invention, Fig. 5 is an enlarged partially cut away, perspective view of a pre-exhaust chamber to show one embodiment of sluice valve arrangement constructed in accordance with the present invention, Fig. 6 is a view partly in section and showing a side portion of a guide rail for a valve member forming part of the sluice valve arrangement of Fig. 6, and Figs. 7 to 9 are views of another embodiment of the present invention, of which Fig. 7 is a partially cut away sectional view, Fig. 8 is a cut away front view, and Fig. 9 is a cut away plan view.

Referring to Figs. 3 to 6, there is shown one embodiment of sluice valve arrangement constructed in accordance with the present invention, and having a cylindrical valve seat member.

The pre-exhaust chambers shown in Figs. 3 and 4 are connectible to a vacuum chamber, to be provided with the sluice valve arrangement shown in Figs. 5 and 6. The pre-chamber, generally shown at 11, is formed of a cylindrical member 10, and has both its ends sealed by arched airtight covers 12 and 12'. A connector pipe, for example, as shown at 13, is to be joined to the vacuum chamber, and has one end flanged at 14 and the other end mounted on the circumference of the barrel portion of the cylindrical member 10 in such a manner that the axis of the connector pipe is at a right angle to that of the member 10 forming the pre-chamber 11. Preferably, the axis of the barrel portion of the pre-chamber 11 is kept in a horizontal state (Fig. 3), or alternatively in a vertical state (Fig. 4).A pipe 1 5 is provided for the introduction of a workpiece into the pre-chamber 11, and has at its outer free end a flange 1 6 to which a cover (not shown) is attached. This pipe 1 5 is held in a given position on the circumference of the pre-chamber 11, which position is opposite to the pipe 13.

The sluice valve arrangement illustrated in Figs.

5 and 6, is placed in an opening 1 7 through which the connector pipe 1 3 is in communication with the pre-chamber 11.

The sluice valve arrangement of Figs. 5 and 6 will now be described with reference to the case shown in Fig. 3 where the axis of the pre-chamber 11 is maintained horizontal.

Guide rails 18 and 19 are positioned on both sides of the opening 1 7, and are mounted on the inner circumference of the pre-chamber 11. Care should then be taken of the size of the opening 1 7, to which is attached the end of the pipe 13. A curved valve member 20 has a curvature equal, at ieast substantially, to that of the inner circumference of the cylindrical member forming the pre-chamber 11, and is supported at both its ends on the guide rails 18 and 19 in a slidable manner by suitable suspension means. Chains, wire ropes, or cables (hereinafter referred to as wire ropes) 21 and 21b, and 21e and 21d are fastened around the guide rails 18 and 19. The wire ropes 21 a-2 1 d have one of their end portions fixed to the respective corners 20a-20d of the valve member 20.The other end portions of thewireropes21aand21b,or21cand21dare combined together under tension, and are tightly wound around a wind-up rotor 22 which is rotatably mounted on the bottom of the prechamber 11 along its axis. The wind-up rotor 22 is driven by an external driving motor 23 connected to the end of an extension of the rotor which passes out of the chamber 11 through the cover 12. A plurality of pulleys 24 are arranged at given intervals in the guide rails 18 and 19, and serve to provide for easy movement of the valve member 20 and function as guides for the wire ropes 21a-21d.

Between the guide rails 1 8, 19 and the valve member 20, there is a mechanism for the hermetic engagement of the valve member 20 with a valve seat member 1 Oa. As illustrated in Fig. 6, this mechanism comprises a plurality of bellows 25 provided in portions of the guide rails 1 8 and 19, which portions correspond to the opening 1 7. The bellows 25 are connected to each other by a suction/exhaust pipe 26 extending in air-tight manner through the wall of the prechamber 11 to a valve 27. To permit air-tight closing of the opening 1 7 by the valve member 20, an amount of compressed air is supplied to the bellows through the valve 27, so that the bellows 25 are expanded to engage the valve member 20 with the inner wall of the pre-chamber 11, thereby closing the pre-chamber 11.

It should be undersood that while the engagement mechanism has been described as comprising a plurality of bellows, other mechanical engagement mechanisms may alternatively be used.

The foregoing sluice valve arrangement operates as follows.

To permit air-tight closing of the opening 17 of the pipe 13 leading to the vacuum chamber, an amount of compressed air is introduced into the bellows 25 through the pipe 26 by manipulation of the external valve 27 to expand the bellows 25 and give a push to the valve member 20 with the bellows, thereby providing air-tight engagement of the valve member 20 with the inner wall of the pre-chamber 11.

In order to allow the pre-chamber 11 to communicate with the vacuum chamber through the opening 17, an amount of compressed air supplied into the bellows 25 is discharged to atmospheric pressure or, preferably, reduced pressure, so that the valve member 20 disengages from the inner wall of the pre-chamber due to the contraction of the bellows 25. The valve member 20 is then movable. The driving motor 23 is driven clockwise and, as a result, the wind-up rotor 22 connected to the motor 23 is rotated clockwise so that, of the wire ropes 21a-21d wound therearound, the ropes 21 a and 21 c are further wound-up, while the ropes 21 b and 21 d are unwound. The valve member 20 is guided by the rails 18 and 19 due to the tension of the wire ropes 21 a and 21 c and the relaxation of the wire ropes 21 b and 21 d, and moves up along the inner wall of the hollow cylinder forming the prechamber 11.

The pulleys 24 arranged in the guide rails 18 and 19 ensure extremely smooth sliding movement of the valve member 20.

To close the pre-chamber again by means of the valve member 20, the driving motor 23 is reversed to wind-up further the wire ropes 21 b and 21 d around the wind-up rotor 22 and, at the same time, to unwind the ropes 21a and 21c.The wire ropes 21 b and 21 d give a pull to the valve member 20, while the wire ropes 21 a and 21 c relax, whereby the valve member 20 is guided by the rails 18 and 19, and moved down along the inner circumference of the cylindrical pre-chamber until it closes the opening 17. An amount of compressed air is thereafter supplied into the bellows 25 through the valve 27, so that the valve member 20 is again engaged with the inner wall of the pre-chamber 11 due to the expansion of the bellows 25. As a consequence, the valve member 20 closes the opening 17 in an air-tight manner.

In the foregoing embodiment, the hollow cylinder forming the pre-chamber 11 is arranged as previously mentioned with its axis horizontal, and is connected at the periphery of its barrel portion with the connector pipe 13, as shown in Fig. 3. Alternatively, however, the hollow cylinder may be arranged with its axis vertical, and connected at the periphery of its barrel portion with the connector pipe 13 leading to the vacuum chamber. The valve member is then horizontaliy moved along the inner circumference of the barrel portion to open or close the opening in the prechamber.

The embodiment of Figs. 7 to 9, to which reference will now be made, differs from that of Figs. 5 and 6 in that the valve seat member is in the form of a hollow sphere and by some of the following features.

A pre-chamber 11 is defined by the interior of the hollow sphere, and is provided with a connector pipe 1 3 leading to a vacuum chamber.

Guide rails 1 8 and 1 9 are arranged on both sides of an opening 1 7 and along the inner circumference of the barrel portion of the prechamber 11. A curved valve member 31 has a curvature equal, at least substantially, to that of the inner circumference of the spherical prechamber 11, and is supported at both its ends on the guide rails 1 8 and 1 9 in a slidable manner by suitable suspension means. The valve member 31 is adapted to be engaged with a valve seat portion 30a surrounding the opening 1 7.

With the arrangements described above with reference to Figs. 3 to 9, it is possible to avoid distortion of the valve member due to vacuum or other loads applied thereon to an extremely high degree, since the valve member has an improved strength over the prior art flat valve. Accordingly, the valve member always serves to open or close properly the opening without any malfunction.

As the inner circumference of a cylindrically or spherically shaped body is used as the valve seat portion, that body per se can be applied as a prechamber, and the sluice valve arrangement can be incorporated into the pre-chamber in such a manner that the valve member is movable along the inner circumference thereof. It is thus unnecessary to provide for a separate valve assembly and to incorporate it into the associated system, resulting in a saving of labour and space.

In addition, since any housing for the valve member is dispensed with, it is very unlikely that leakage and breakdown problems will arise.

Thus, as mentioned above, there is ensured airtight closing or opening of the valve member, which is adapted to make a hermetic partition or communication between a vacuum chamber and the atmosphere or the pre-chamber. The valve member is also of such a strength that any reinforcing work or material can be dispensed with.

Claims

1. A valve arrangement adapted to open or close an opening leading to a vacuum chamber, includes a valve seat member comprising a member of cylindrical or spherical shape having an opening therein, a guide rail secured to the inner circumference of said valve seat member, a valve member movably supported on said guide rail, and means for enabling air-tight engagement of said valve member with the valve seat portion of said seat member.

2. A valve arrangement as claimed in claim 1, in which said valve member has a curvature which is equal to that of said cylindrically or spherically shaped member.

3. A valve arrangement as claimed in claim 1 or 2, in which the valve seat portion of said seat member is defined by the inner circumference of said cylindrically or spherically shaped member.

4. A valve arrangement as claimed in any one of claims 1 to 3, in which said engagement means comprises a plurality of bellows which are expandible by a compressed gas.

5. A valve arrangement substantially as hereinbefore described with reference to Figs. 3, 5 and 6 of the accompanying drawings.

6. A valve arrangement substantially as hereinbefore described with reference to Figs. 4 to 6 of the accompanying drawings.

7. A valve arrangement substantially as hereinbefore described with reference to Figs. 7 to 9 of the accompanying drawings.

8. A vacuum treatment system including a vacuum chamber and a valve arrangement as claimed in any preceding claim for opening and closing an opening in the vacuum chamber.