JP2649662B2 - Gate valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate valve, and more particularly to a gate valve used in a processing apparatus for semiconductor wafers and the like.

[0002]

2. Description of the Related Art In processing apparatuses for processing semiconductor wafers and liquid crystal substrates, wafers and substrates are taken in and out of various processing chambers through passages, and the passages are provided with gate valves. I have. It is necessary to prevent impurities from entering the processing chamber as much as possible.

The above gate valve is disclosed in, for example, Japanese Utility Model Laid-Open No. 51-15639 and Japanese Patent Laid-Open No. 58-15678.
There is one shown in Japanese Patent Publication No. In such an example,
The valve desk is moved up and down in a state of being separated from the valve seat, and is pressed against the valve seat from a side thereof at a position facing the valve seat, thereby bringing the valve desk into contact with the valve seat.

Further, as disclosed in Japanese Utility Model Laid-Open Publication No. 52-93930, there is also known a gate valve driving device in which a valve disc inserted from the outside of a valve box is inclined to press a valve desk against a valve seat. is there.

[0005]

However, in the above-mentioned conventional gate valve, since the valve desk is pressed against the valve seat, many mechanically movable parts such as valve restraints, pillars, springs, stoppers, rollers and the like are formed in the passage. Located within
There is a drawback that impurities generated by mechanical abrasion or the like from these materials are likely to be mixed into the processing chamber.

Further, in the latter conventional type, the gate valve is obliquely downwardly directed and abuts against the sealing material to close the gate valve, and the two slide slightly with each other. Therefore, contamination in the passage due to abrasion of the sealing material cannot be prevented.

The present invention has been made to eliminate the above disadvantages.

[0008]

A gate valve according to the present invention comprises a valve box, a valve desk arranged in the valve box so as to be in contact with a valve seat provided in the valve box, and A connected valve rod that vertically and tiltably projects airtightly from the inside of the valve box to the outside of the valve box via a bellows, and the valve index does not face the position facing the valve seat via the valve rod. The valve is tilted to a position, and after the valve desk is separated from the valve seat and becomes a position facing the valve seat, the valve rod is tilted so that the valve desk is pressed against the valve seat. Consisting of moving means provided outside the box,
The moving means includes a piston cylinder, a yoke connected to a piston rod of the piston cylinder, a block connected to an upper portion of the valve rod, a step formed on an upper surface of the block, and a step facing the step. A step formed on the lower surface of the yoke, a plate-like cam having a rhombic cross-section that is inclined and disposed between the steps, and a spring that connects the yoke and the block to each other to suppress relative movement in the axial direction. And a guide formed on the side surface of the piston cylinder to guide the block vertically and tiltably, and when the yoke is pressed so as to approach the block, the plate-like cam becomes horizontal. As a result, the valve rod is tilted about the block, and the valve desk is pressed against the valve seat.

[0009]

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

1 to 5, reference numeral 1 denotes a valve box, 2 denotes a rectangular valve seat provided in the valve box 1, and 3 denotes a valve seat disposed in the valve box 1 so as to be in contact with the valve seat 2. 4 is a piston cylinder provided on both sides of the upper part of the valve box 1, 5 is its piston, 6 is a piston rod, 7 is a yoke connected to the upper part of the piston rod 6, and 8 is the valve 2 shows a valve rod projecting from the desk 3 to the outside of the valve box 1.

In the present invention, one end of a tubular bellows 9 which can be extended and contracted in the axial direction is airtightly connected to a portion of the valve rod 8 protruding outside the valve box 1, and the other end is airtightly connected to the valve box 1. , So that the valve rod 8 projects from the inside of the valve box 1 to the outside of the valve box 1 in an airtight manner.

A block 10 is provided above the valve rod.
Are connected on the center lines on both sides of the block 10.
Projecting so as to extend in a direction perpendicular to the direction in which the valve desk 3 is pressed against the valve seat 2, and a guide groove 12 having a predetermined length for guiding the pivot 11 is provided on the center line of the side surface of the two piston cylinders 4. The block 10 is provided with the pivot 11 supported by the lower end of a guide groove 12 formed on the side surface of the piston cylinder 4 as shown in FIG.
When pushed in the direction of arrow A shown in FIG. 1, the valve rod 8 tilts about the pivot 11, and the valve desk 3 connected to the lower end of the valve rod 8 moves in the direction of arrow B in FIG. To be pressed.

Further, grooves 1 are provided on both sides of the block 10.
3, a tension spring 15 is disposed in the groove 13, and a hanging portion 1 is formed on a side surface of the yoke 7 on the valve seat 2 side.
4, one end of a tension spring 15 is attached to the hanging portion 14, and the other end is fixed to the block 10.

Further, opposing steps 16a and 16b are formed on the upper surface of the block 10 and the lower surface of the yoke 7, respectively.
When the plate-like cam 17 having a rhombic cross section is disposed between the two and inclined, and the yoke 7 is lowered by the piston rod 6 of the piston cylinder 4, the block 10
When the yoke 7 is further pushed down toward the block 10 in a state where the pivot 11 of the block 10 comes into contact with the lower end of the guide groove 12 formed on the side surface of the piston cylinder 4, the inclination The plate-like cam 17 becomes substantially horizontal, so that the block 10 is moved about the pivot 11 against the spring force of the tension spring 15 in the direction of the arrow A.

It is preferable that the positional relationship between the plate-like cam 17 and the tension spring 15 is determined so as to always form a C-shape as shown in FIG.

Since the gate valve of the present invention has the above-described structure, when closing the valve, the piston cylinder 4 is operated to lower the yoke 7, and at the same time, the block 10 is closed.
Are lowered integrally while being frictionally coupled to the hanging portion 14 of the yoke 7 by the tension spring 15, and as a result, the valve desk 3 is lowered to a position facing the valve seat 2 as shown in FIGS.
At this position, the pivot 11 comes into contact with the lower end of the guide groove 12 and is positioned.

In this state, the block 10 does not further descend, but the yoke 7 continues to descend further, and the yoke 7 is pushed down with respect to the block 10, so that the inclined plate-like cam 17 becomes substantially horizontal. Accordingly, the block 10 is moved in the horizontal direction against the spring force of the tension spring 15, and this movement causes the block 10 to tilt about the pivot 11 in the direction of the arrow A against the spring force of the tension spring 15, As a result, the valve desk 3 connected to the lower end of the valve rod 8 moves in the direction of the arrow B and is strongly pressed by the valve seat 2.

If the lowering of the yoke 7 by the piston cylinder 4 is stopped in this state, the valve disc 3 is kept pressed by the valve seat 2.

When the valve is opened, the yoke 7 is raised by operating the piston cylinder 4. In this case, the block 10 does not immediately rise due to the large frictional force between the valve seat 2 and the valve desk 3, while the side surface of the block 10 is separated from the hanging portion 14 of the yoke 7 and the two are frictionally connected. As a result, only the yoke 7 is pulled upward relative to the block 10 so that the tension spring 1
5, the plate cam 17 tilts again, and at the same time, the tilt of the valve rod 8 is released, and the valve desk 3 moves in the direction opposite to the direction of the arrow B to separate from the valve seat 2, and then the yoke 7
At the same time, the block 10 moves up together with the valve desk 3, and the valve is opened as shown in FIG.

In the above embodiment, when the valve rod 8 is tilted, the cylindrical bellows 9 is also tilted and deformed. However, the position at which the pivot 11 is positioned is set at a substantially middle height of the cylindrical bellows 9. By the way, the bellows 9
This is preferable because the inclination deformation can be minimized.

[0021]

As described above, according to the gate valve of the present invention, a mechanical part for pressing the valve desk 3 against the valve seat 2 in the valve box 1 airtightly partitioned from the outside by the bellows 9. And the valve desk 3 descends to a position facing the valve seat 2 and is pressed at right angles thereto, so that impurities such as wear and the like are generated in the valve box 1 as in the conventional case. There is no danger, and the driving means for the valve desk 3 can have an extremely simple configuration. In addition, since the block 10 is disposed between the piston cylinders 4, there is a great advantage that the height can be reduced and the shape of the entire gate valve can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a gate valve of the present invention in a state immediately before a valve is closed.

FIG. 2 is a longitudinal sectional front view of the gate valve of the present invention in a state immediately before the valve is closed.

FIG. 3 is a front view of the gate valve of the present invention in a state where the valve is opened.

FIG. 4 is a perspective view of a piston cylinder portion of the gate valve of the present invention.

FIG. 5 is a perspective view of a block portion of the gate valve of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve box 2 Valve seat 3 Valve desk 4 Piston cylinder 5 Piston 6 Piston rod 7 Yoke 8 Valve rod 9 Cylindrical bellows 10 Block 11 Axis 12 Guide groove 13 Groove 14 Hanging part 15 Tension spring 16a Step 16b Step 17 Plate cam

Claims (1)

(57) [Claims] 1. A valve box, a valve desk arranged in the valve box so as to be in contact with a valve seat provided in the valve box, and a valve box connected to the valve desk, from inside the valve box to outside the valve box. A valve rod protruding airtightly vertically and tiltably via bellows,
The valve index is movable via the valve rod to a position facing the valve seat and a position not facing the valve seat. After the valve desk is separated from the valve seat and faces the valve seat, And a moving means provided outside the valve box so that the valve desk is pressed against the valve seat. The moving means is connected to a piston cylinder and a piston rod of the piston cylinder. A yoke, a block connected to the upper part of the valve rod, a step formed on the upper surface of the block, a step formed on the lower surface of the yoke so as to face the step, and between the two steps. A plate-like cam having a rhombic cross section arranged in an inclined manner, a spring connecting the yoke and the block to each other so as to suppress relative movement in the axial direction, and an upper spring for guiding the block vertically and tiltably. When the yoke is pressed so as to approach the block, the plate-like cam becomes horizontal and the valve rod inclines about the block, A gate valve, wherein a valve desk is pressed against the valve seat.