JPH08114282A - High vacuum pressure valve - Google Patents

Abstract

PURPOSE: To provide a high vacuum pressure valve that is positive in sealing and large in the stroke value of a valve element, and further excellent in durability of a sealing function. CONSTITUTION: Two ports 2 and 3, a valve seat 4 in a passage lying between these ports and an opening 5 are all installed in a valve body 1, while a partition wall 8 having a projection 8a and formed with a nonmagnetic thin plate is installed in space between the body 1 and a bonnet 6 attached to this opening 5, and a magnet coupling 14 and a seal member 15 are installed in an air space between the bonnet and the projection in an integrally shiftable manner. In succession, a magnet coupling 24 to be opposed to the magnet coupling 14 is attached to a valve stem 21 of a valve element 20 extending in the projection via the partition wall. When compressed air is fed to an air space 16a of a driving port 17, the coupling 14 moves, whereby the valve element opens the valve seat by dint of the coupling 24 synchronously shifting by dint of attraction between both the couplings, and when air in the air space 16a is exhausted, the valve element closes the valve seat by dint of energizing force of a return spring 27.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a high vacuum pressure valve.

[0002]

2. Description of the Related Art In a high vacuum pressure valve, a bellows is used to seal between a flow passage, which is usually subjected to high vacuum pressure, and a drive portion of a valve body which opens and closes a valve seat provided in the flow passage. (For example, see Japanese Utility Model Laid-Open No. 03-107587). The seal of the valve body drive portion by the bellows can obtain high airtightness, but the expansion and contraction amount of the bellows, which is the stroke amount of the valve body, and the durability of the bellows are in the opposite relationship, and the relationship is Since it is an index, the number of peaks must be increased in order to improve the durability of the bellows. Therefore, if the durability of the bellows is increased, there is a problem that the axial length of the bellows becomes long and the length of the valve becomes extremely long.Therefore, the length of the valve is shortened and the durability of the bellows is not deteriorated. Therefore, the stroke amount of the valve body must be reduced.

On the other hand, the conductance, which is the passage ability of the valve, is related to the cross-sectional area of the valve seat and the area of the cylindrical portion due to the stroke of the valve body, where D is the diameter of the valve seat and S is the stroke of the valve body. To make them equal, S = D /
It must be 4. Therefore, when the stroke amount of the valve body is reduced, there is a problem that the conductance of the valve is reduced. Therefore, the known high vacuum pressure valve using the bellows sacrifices the conductance of the valve to make the bellows have durability of about 500,000 to 1,000,000 times.

[0004]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to provide a high vacuum pressure valve having a reliable seal, a large stroke amount of the valve element, and a large durability of the sealing function. .

[0005]

In order to solve the above problems, a high vacuum pressure valve according to the present invention is provided with a port connected to a chamber, a port connected to a vacuum source, and a flow path connecting these ports. A valve body having a valve seat of
In a high vacuum pressure valve including a valve body that opens and closes the valve seat, and a drive unit and a return spring of the valve body, a space between the valve body and a bonnet attached to the valve body is projected into the bonnet. A magnetic coupling on the drive side, which is airtightly divided by a partition wall having a convex portion and made of a non-magnetic material, and a drive portion of the valve body is movably inserted into a space between the bonnet and the convex portion, and a valve body. Fixed to the drive side magnet coupling with the partition wall sandwiched between the driven side magnet coupling, and one of the spaces between the convex portion and the bonnet partitioned by the drive side magnetic coupling, A drive port for supplying and discharging a pressure fluid is provided in the space, and the other of the spaces is communicated with the outside.

In order to solve the same problem, a seal member for shutting off the communication between the drive port and the outside is provided in the space between the bonnet and the convex portion of the high vacuum pressure valve integrally with the drive side magnetic coupling. It is characterized by being provided so as to be movable.

Further, in order to solve the same problem, these high vacuum pressure valves are provided with a shielding member which is slidable relative to the valve body and shields the convex portion of the partition wall from the flow path, and the valve in the shielding member is provided. It is characterized in that a labyrinth is formed on the surface facing the rod.

[0008]

When the pressure fluid is not supplied from the drive port, the valve element closes the valve seat by the urging force of the return spring. When pressure fluid is supplied from the drive port to the space between the bonnet and the cylinder, the magnet coupling on the drive side moves in the specified direction, and the attraction force between the magnet coupling causes the magnet coupling on the driven side to synchronize with this. Move in the same direction, the valve body opens the valve seat and the flow paths between the ports communicate with each other. When the pressure fluid in the space is discharged, the urging force of the return spring causes the valve body and the magnet coupling on the driven side to return and the valve body closes the valve seat.
Due to the attractive force between the magnet couplings, the drive side magnetic couplings return to their original state.

In this case, since the flow path between the ports is hermetically sealed by the partition wall, outside air does not flow in. Further, unlike the sealing by the bellows, the partition wall does not move even if the valve body moves, so the durability of the sealing function is improved. Further, even if the stroke amount of the magnetic coupling is increased, the length of the entire valve does not become so long as compared with the expansion and contraction of the bellows, so that the conductance of the valve can be increased.

Further, since the seal member for blocking the communication between the drive port and the outside is provided in the space between the bonnet and the convex portion, the pressure fluid supplied from the drive port does not leak to the outside. Further, since the shielding member which is slidable relative to the valve rod and covers the inside of the convex portion of the partition wall is provided and the labyrinth is formed on the surface of the shielding member facing the valve rod, the products generated by the work in the chamber are Adhesion to the driven-side magnet coupling can be reduced as much as possible.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings show an embodiment of the present invention, in which a valve body 1 in this high vacuum pressure valve has ports 2 and 3 formed in directions orthogonal to each other and a valve seat in a flow path for connecting ports 2 and 3 to each other. 4 and an opening 5 facing the valve seat 4
The bonnet 6 is attached to the. The partition wall 8 mounted between the valve body 1 and the bonnet 6 is formed of a thin plate of a non-magnetic material such as aluminum, and has a convex portion 8a protruding into the bonnet 6 and a flange 8b on the outer periphery thereof. The periphery of the flange 8b is hermetically sealed by a seal ring 9 provided between the valve body 1 and the bonnet 6.

In the space between the bonnet 6 and the convex portion 8a of the partition wall 8, a desired number of annular yokes 11 and permanent magnets 12 are sequentially laminated, and are integrally connected by bolts 13 ... A magnet coupling 14 is inserted so as to be movable in the axial direction, and a seal member 15 that hermetically seals the space is attached to the valve body 1 side of the magnet coupling 14 so as to be integrally movable. The bonnet 6 is provided with a drive port 17 for supplying / discharging compressed air to / from the space 16a on the side where the seal member 15 is installed, and the space 16b on the opposite side is between the bonnet 6 and the top wall of the convex portion 8a of the partition wall. It communicates with the outside by a gap 18 in the circumferential direction.

The valve body 20 for opening and closing the valve seat 4 has a valve rod 21 projecting into the convex portion 8a of the partition wall 8, and is driven between the flange 21a at the tip and the fixing member 23 attached in the middle. The side magnetic coupling 24 is fixed. Similar to the magnet coupling 14, the magnet coupling 24 is configured by stacking a desired number of annular yokes 11 and permanent magnets 12 in sequence, except that the inner and outer diameters are different.

A shield member 26 is slidably mounted on the outer periphery of the valve rod 21, and a flange 26a of the shield member 26 is partitioned by a biasing force of a return spring 27 that is compressed between the shield member 26 and the valve body 20. It is in contact with the flange 8b of the wall 8. Further, a labyrinth 28, ... Is formed on a surface of the tubular portion 26b provided on the shielding member 26, the surface facing the valve rod 21 passing through the tubular portion (see FIG. 2). Reference numeral 29 in FIG. 1 is a seal ring fitted in the groove of the valve body 20 for sealing the valve seat 4.

The above embodiment is used by connecting the port 2 to the chamber and the port 3 to a vacuum source such as a vacuum pump (both the chamber and the vacuum pump are not shown). When the compressed air is not supplied to the space 16a, the valve body 20 and the driven-side magnet coupling 24 move downward in the figure by the urging force of the return spring 27, so that the valve body 20 closes the valve seat 4 and the magnet. The magnetic coupling 14 on the drive side is also moved downward due to the attractive force between the couplings. When compressed air is supplied from the drive port 17 to the space 16a,
The drive-side magnet coupling 14 moves upward in the drawing, and the driven-side magnet coupling 24 also moves upward due to the attractive force between the magnet couplings.
0 opens the valve seat 4. In this case, the stroke amount of the valve body 20 becomes the stroke amount of the magnet couplings 14 and 24, and the partition wall 8 that partitions the magnet couplings does not move unlike the bellows, so the durability of the sealing function is large. Moreover, the conductance of the valve can be increased. Further, since the flow passage between the ports 2 and 3 on which the vacuum pressure acts is airtightly sealed to the outside by the partition wall 8, the outside air does not flow into the flow passage between these ports.

When the compressed air supplied to the space 16a is discharged, the valve body 20 and the magnet coupling 24 are restored by the urging force of the return spring 27, and the valve body 20 closes the valve seat 4, so that the ports 2 and 3 are closed. The communication between them is cut off, and the magnet coupling 14 also returns to its original position due to the attractive force between the magnet couplings.

When the product generated by the operation in the chamber flows into the convex portion 8a of the partition wall 8 and adheres to the magnets 12, ... Of the magnet coupling 24, the movement of the magnet coupling 24 is prevented. Although there is a risk of obstruction, in the above embodiment, the labyrinths 28, ... Provided on the cylindrical portion 26b of the shielding member 26 maintain the air permeability between the flow path and the convex portion 8a while maintaining the molecular flow region. In the high vacuum state, the products are made difficult to flow into the magnets 12 ...

[0018]

According to the high vacuum pressure valve of the present invention, the space between the flow passage between the ports and the drive portion of the valve body is hermetically sealed by the partition wall, so that the outside air does not flow into the flow passage. . Further, unlike the bellows, the partition wall does not move even when the valve body opens and closes the valve seat, so the durability of the sealing function is improved. Further, even if the stroke amount of the magnetic coupling is increased, the length of the entire valve does not become so long, so that the conductance of the valve can be increased. Further, even if the product is generated by the work in the chamber, the labyrinth provided in the cylindrical portion of the shielding member can prevent the product from flowing into the convex portion.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment.

FIG. 2 is an enlarged sectional view of a main part.

[Explanation of symbols]

 1 valve body 2, 3 port 4 valve seat 6 bonnet 8 partition wall 8a convex portion 14, 24 magnet coupling 15 sealing member 16a, 16b space 20 valve body 26 shielding member 26a tubular portion 27 return spring 28 labyrinth

Claims (3)

[Claims] 1. A valve body having a port connected to a chamber, a port connected to a vacuum source, and a valve seat in a flow path for communicating these ports, a valve body for opening and closing the valve seat, and In a high vacuum pressure valve having a valve body drive unit and a return spring, a section made of a non-magnetic material having a protrusion protruding into the bonnet, between the valve body and the bonnet attached to the valve body. Airtightly divided by a wall, the drive unit of the valve body, a drive-side magnetic coupling movably inserted into the space between the bonnet and the convex portion,
One of the spaces between the protrusion and the bonnet, which is fixed to the valve body and includes a drive-side magnet coupling that faces the drive-side magnet coupling with the partition wall in between, and a driven-side magnet coupling that is partitioned by the drive-side magnetic coupling. A high vacuum pressure valve, characterized in that a drive port for supplying and discharging a pressure fluid is provided in the space, and the other of the space is communicated with the outside. 2. A seal member for blocking communication between the drive port and the outside is provided in a space between the bonnet and the convex portion so as to be movable integrally with the drive side magnetic coupling. The high vacuum pressure valve described in 1. 3. A shielding member which is slidable relative to the valve body and shields the convex portion of the partition wall from the flow path, and a labyrinth is formed on a surface of the shielding member facing the valve rod. The high vacuum pressure valve according to claim 1 or 2.