JP2002106729A - Gate valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized gate valve simplified in structure. SOLUTION: This gate valve 1 is provided with a first driving cylinder 2 projecting a piston rod 23 downward, a second driving cylinder 3 which is fixed to the piston rod 23, is elevatable/lowerable by driving the first driving cylinder 2 and elongates and contracts the piston rod 32 in a direction perpendicular to a valve seat surface 4 and valve elements 11 and 12 at an upper end of a valve element rod 13 which is journaled on the piston rod 32 of the second driving cylinder 3 and is journaled by a slider 14 slidable in the vertical direction at the middle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate valve which eliminates generation of particles due to rubbing of a seal member held by a valve body, and more particularly to a small gate valve having a simplified structure.

[0002]

2. Description of the Related Art Semiconductor manufacturing is performed in a vacuum atmosphere, and particularly high cleanliness is required. For this reason, gate valves are widely used as a means of isolating a work room to create such an atmosphere.
Various proposals have been made to prevent generation of particles due to the opening and closing operations. In other words, when opening the gate valve for loading and unloading wafers, it is necessary to not only separate the valve body from the valve seat surface but also to retreat it greatly from the gate port.
This is because the valve element must be moved in the direction, and if this operation is performed by a single operation, the seal member made of a rubber material or the like is rubbed with the opening and closing operation. for that reason,
Conventionally, various types of valves that open and close valves in a two-stage operation have been proposed.

[0003] As a first prior art example in which such a proposal has been made, the one disclosed in Japanese Patent Application Laid-Open No. H2-222967 can be mentioned. FIG. 9 is a diagram showing the gate valve of the publication. The gate valve 100 includes a cylinder 102 for moving the valve body 101 in the vertical direction, and cylinders 103 and 10 for abutting and separating the valve body 101 from and against the valve seat surface.
4 is provided. And the cylinder 102
The piston rod is directly fixed to the valve body 101 via the valve body operation rod 105. The cylinder 10
Reference numerals 3 and 104 denote swing frames 1 fixed to the valve body operation rod 105.
07 is pivoted about the pin 106.
The piston rod is rotatably supported via. Cylinder 1
The cylinder tubes 03 and 104 are pivotally supported at the cylinder tube ends so as to swing themselves.

Therefore, the gate valve 100 is
The valve body 101 is moved in the vertical direction by the driving of the valve body 2, and the valve body 10 is moved between a lowered shut-off position where the valve can be closed in front of the gate port and a raised retreat position where the gate port is largely opened.
Move 1 Then, the valve element 101 arranged at the shut-off position by the cylinder 102 is moved to the next cylinder 103,
The drive of 104 causes the valve seat surface to come into contact with / separate from the valve seat surface.
This is because the piston rods of the cylinders 103 and 104 expand and contract, so that the valve body operation rod 105
Is performed by swinging.

On the other hand, as a second conventional example, Japanese Patent Laid-Open No. 11-2
The gate valve described in 41776 is mentioned. FIG. 10 is a diagram showing the gate valve of the publication. The gate valve 200 includes a cylinder 202 for bringing the valve body 201 into contact with and away from the valve seat surface, and a cylinder 202
Cylinder 2 for moving valve body 201 in the vertical direction
And a pressure medium conduit 204 for supplying a working fluid (compressed air) for driving each of the cylinders 202 and 203.

Therefore, in the gate valve 200, the piston 20 is operated in accordance with the ratio between the piston surfaces F1 and F2 and between the piston surfaces F3 and F4.
5, 206, 207 are pressurized by compressed air, and the operation for opening and closing the valve is performed by the pressure difference. That is,
The valve body 201 is moved in the vertical direction by driving the cylinder 203, and a lowered closing position in front of the gate opening where the valve can be closed,
The valve body 201 is moved between the raised position and the retracted position where the gate port is largely opened. And the following cylinder 2
By driving the valve 02, the valve body 201 arranged at the shut-off position is brought into contact with and separated from the valve seat surface.

[0007]

However, such a conventional gate valve has the following problems. For example, in the gate valve 100 of the first conventional example, since the outputs of the two types of cylinders 102 and the cylinders 103 and 104 are both applied to the valve body operation rod 105, the cylinders 103 and 1
04 so as to be able to swing, swing frame 107 and connecting plate 1
08, etc., the structure is complicated, and furthermore, such a structure increases the size of the entire apparatus. On the other hand, the gate valve 200 of the second conventional example is different from the first conventional example in that the structure for vertically moving and horizontally moving the valve element 201 is simplified, but each cylinder 202,
Since the operation efficiency is reduced by driving the 203, it is necessary to increase the size of the apparatus accordingly.

Therefore, an object of the present invention is to provide a small-sized gate valve having a simplified structure in order to solve such a problem.

[0009]

According to the present invention, there is provided a gate valve for raising and lowering a valve element for opening and closing a gate between a shutting position in front of the gate opening and a retracted position lowered from the shutting position. In a gate valve operated in two stages of 1 drive and 2nd drive for contacting / separating from the valve seat surface of the gate opening at the shut-off position, a first valve having a piston rod protruding downward. A drive cylinder, a second drive cylinder fixed to the piston rod and movable up and down by driving a first drive cylinder, and extending and retracting the piston rod in a direction perpendicular to the valve seat surface; A valve element is provided at an upper end of a valve element rod which is pivotally supported by a piston rod of a cylinder, and which is pivotally supported by a slider which can slide vertically in the middle.

Therefore, when the second drive cylinder moves up and down by driving the first drive cylinder, the valve body rod also moves up and down in the same direction together with the axially supported slider, so that the valve body performs the first drive, and the second drive cylinder moves in the shut-off position. When the drive cylinder is driven, the valve body rod swings like a lever around the axis with the slider, and the valve body contacts and separates from the valve seat surface. Therefore, in the gate valve of the present invention, the valve body is formed by the two cylinders in the first
Further, the structure for the second driving can be simplified, and the size can be reduced.

Further, the gate valve of the present invention raises and lowers the valve element for opening and closing the gate port between a blocking position in front of the gate port opening and a retracted position lowered from the blocking position.
A first drive in which a piston rod is protruded downward in a gate valve operated in two stages: a drive and a second drive for contacting and separating from a valve seat surface of the gate opening at the shutoff position. A second drive cylinder disposed above the first drive cylinder and extending and retracting a piston rod in a direction perpendicular to the valve seat surface; and a second drive cylinder rotatably supported on the piston rod side of the first drive cylinder. A valve body is provided at an upper end of a valve body rod provided with a rail groove in which a roller provided on a piston rod of a second drive cylinder is inserted.

Therefore, when the piston rod expands and contracts by driving the first drive cylinder, the valve rod moves up and down along the rail groove to perform the first drive, and the second drive cylinder is driven in the shut-off position. As a result, the valve body rod swings via the roller inserted in the rail groove, and the valve body contacts and separates from the valve seat surface. Accordingly, the gate valve of the present invention
The structure for the first and second drive of the valve body by the individual cylinders can be simplified, and the size can be reduced.

Further, in the gate valve according to the present invention, the first drive cylinder includes an ascending port and a descending port for supplying a working fluid for moving the piston up and down, and a working fluid supplied from the ascending port to the piston. A discharge port that discharges at the stroke end of the rod, and the piston rod has a small-diameter portion that is non-contact at the stroke end with a rod packing provided between the ascent port and the exhaust port. The second drive cylinder is provided with a forward port and a backward port for supplying a working fluid for moving the piston back and forth, and a working fluid supplied from the forward port or the backward port after the operation of the piston. A discharge port for discharging, and a seal packing provided between the forward port or the retreat port and the discharge port has a piston. After the operation, the piston rod is brought into a non-contact state with the piston rod, and the discharge port of the first drive cylinder is connected to the forward or backward port of the second drive cylinder, and the discharge port of the second drive cylinder is connected. The port is connected to a lowering port of the first drive cylinder.

Therefore, when the valve is closed, the valve body is raised to the shut-off position by the working fluid supplied from the raising port of the first drive cylinder, and at this time, communication with the discharge port is generated by the small diameter portion of the piston rod. The working fluid supplied to the first drive cylinder flows out and is supplied to the second drive cylinder, and the second drive cylinder is driven. On the other hand, when the valve is opened, the valve body is separated by the working fluid supplied from the forward or backward port of the second drive cylinder,
At that time, when the piston moves, the seal packing is brought into a non-contact state, the working fluid flowing out of the discharge port is supplied to the first drive cylinder, and the first drive is performed. Therefore, the working fluid supplied from one location is supplied to the other cylinder by the mechanical operation of one cylinder at the time of valve closing and valve opening, so that the control of the opening / closing operation of the valve element performed in two stages is performed. Simplified.

[0015]

Next, an embodiment of a gate valve according to the present invention will be described with reference to the drawings. 1 to 3 are cross-sectional views showing a gate valve according to the first embodiment.
FIGS. 1 to 3 show a state until the valve is closed (a state from the reverse until the valve is opened). FIG. 4 is a front view of the gate valve of the present embodiment, and shows a closed state corresponding to FIG. Therefore, the configuration of the gate valve according to the present embodiment will be described first with reference to FIGS.

The gate valve 1 is suspended from a base 6 provided with a gate port 5, and a first driving cylinder 2 and a second driving cylinder 3 as driving means are vertically connected. With such a first drive cylinder 2, the gate port 5
A first drive for raising and lowering the valve body between a forward shut-off position (FIG. 2) and a retracted position (FIG. 1) lowered from that position, and the second drive cylinder 3 releases the valve body in the shut-off position. A second drive for abutting (FIG. 3) and separating (FIG. 2) on the seat surface 4 is performed, and the gate valve 1 is configured to open and close in two stages.

The valve body of the gate valve 1 has a seal ring 12 fitted on the valve seat surface 4 side of a partition plate 11, and the partition plate 11 is integrally formed with the valve rod 13 so as to form a T-shape. Fixed. Valve rod 13 arranged vertically
Is supported by a slider 14 at an intermediate portion, and the slider 14 is mounted on a rail 1 provided on the first drive cylinder 2.
5 and 15 are slidably provided. Therefore,
In the gate valve 1, a first drive for raising and lowering the valve element is performed by moving the valve element rod 13 up and down, and the valve element is brought into contact with the valve seat surface 4 by swinging the valve element rod 13. -It is comprised so that the 2nd drive which separates may be performed.

Next, the first drive cylinder 2 and the second drive cylinder 3 for raising and lowering and contacting / separating will be described. The first drive cylinder 2 has a cylinder tube 20 vertically installed on a base 6 with a ceiling plate 21 interposed therebetween, and a piston rod 23 fixed to a slidable piston 22 protruding downward. The cylinder tube 20 is formed so that the inside is airtight by a sealing material, and the upper and lower sealed spaces are variably partitioned by a piston 22. The piston rod 23 is slidably supported by a bush 24, and the sliding portion thereof is kept airtight by rod packings 25 and 26. The first drive cylinder 2 has a rising port 27 communicating with the lower chamber of the piston 22, a lowering port 28 communicating with the upper chamber, and a working fluid supplied to the lower chamber of the piston 22. A discharge port 29 is formed between the rod packings 25 and 26.

Next, the second drive cylinder 3 is laterally fixed to the lower end of a piston rod 23 projecting from the first drive cylinder 2. The second drive cylinder 3 is
A piston 31 which is smaller than the first drive cylinder 2 and is slidable in the cylinder tube 30 in the front-rear direction (left and right in FIG. 3) is mounted, and a piston rod 32 fixed to the piston 31 is moved forward ( 3 (left side in FIG. 3). The second drive cylinder 3 is provided with a forward port 33 on the back side and a backward port 34 on the opposite side with the piston 31 interposed therebetween. Furthermore,
A discharge port 36 is formed in front of the piston 31 with a V-shaped seal packing 35 interposed therebetween. The retreat port 34 and the discharge port 36 are bored in the same chamber of the cylinder tube 30 partitioned by the piston 31, but when the piston 31 is at a position as shown in FIG. Is divided by

Each operation of the first drive cylinder 2 and the second drive cylinder 3 is executed by the pressure of compressed air which is a working fluid supplied from a predetermined port. Specifically, when the valve is closed, the ascending port 27 is provided, and when the valve is opened, the retreat port 34 is supplied with compressed air from one place.
The expansion and contraction operation of the second drive cylinder 3 is performed. Therefore, the first drive cylinder 2 and the second drive cylinder 3
The discharge port 29 and the forward port 33, and the discharge port 36 and the downward port 28 are connected as indicated by arrows. Then, although not shown, the air pump is operated via the switching valve to supply compressed air to the ascending port 27 and the retreating port 34, respectively.
34.

The lower end of the valve rod 13 is pivotally mounted at the tip of the piston rod 32 of the second drive cylinder 3. The valve rod 13 is pivotally mounted on the slider 14 between the lower end and the upper partition plate 11 which are pivotally mounted on the valve rod 13, and can swing about the shaft of the slider 14 as a fulcrum.
The slider 14 has a rail 15 fixed to the front surface of a cylinder tube 20 of the first drive cylinder 2 and is provided so as to slide up and down there. In particular, the slider 14
It can ascend to a position where it comes into contact with the ceiling plate 21, which is the upper limit of the piston 22 of the first drive cylinder 2,
Further, the partition plate 11 is adjusted to the height of the gate opening 5.

Next, the opening / closing operation of the gate valve 1 will be described. The operation of closing the gate valve 1 from the valve closing state shown in FIG. 1 to the states shown in FIGS. 2 and 3 will be described first. When closing the gate valve 1, compressed air is supplied from the ascending port 27 of the first drive cylinder 2 as described above (arrow). Cylinder tube 2
The compressed air supplied into the cylinder 0 pressurizes and pushes up the piston 22 from below, and the piston rod 23 is pulled up with the rising piston 22 (arrow). Further, the second drive cylinder 3 is lifted together with the piston rod 23, whereby the valve body rod 13 is pushed up from the lower end, the slider 14 slides on the rail 15, and the partition plate 11 moves as shown in FIG. 5 height.

Subsequently, the compressed air that has driven the first drive cylinder 2 flows out of the discharge port 29 and is supplied to the second drive cylinder 3 (arrow). The supply of the compressed air is provided with a time difference as follows so that the first drive cylinder 2 and the second drive cylinder 3 operate stepwise. When the piston rod 23 rises from FIG. 1 to FIG. 2, the V-shaped rod packing 25 slides on and seals the piston rod 23, so that compressed air does not flow from the rising port 27 to the discharge port 29. .
However, the piston rod 23 has a narrow, small diameter portion 2.
3a is formed, which is located on the rod packing 25 at the stroke end of the piston 22 (FIG. 2). Therefore, the compressed air supplied from the ascending port 27 flows through the gap formed by the small diameter portion 23a, and
To the forward drive port 33 of the second drive cylinder 3.

Therefore, the compressed air supplied from one place first pressurizes the piston 22 to perform a first drive to raise the partition plate 11 to the shut-off position, and the first drive is continued by the compressed air supplied from the same place. The second drive is performed. Then, when compressed air is also supplied to the second drive cylinder 3 shown in FIG. 2, the piston 31 is pressurized and slides forward (left side in the drawing) together with the piston rod 32 (arrow). Then, the lower end of the valve rod 13 axially attached to the tip of the piston rod 32 is pushed in the same direction.

By driving the second drive cylinder 3, the valve rod 13 swings like a lever with the intermediate portion pivotally attached to the slider 14 as a fulcrum, and its upper end is located on the rear side opposite to the lower end pushed forward. Attracted to. Therefore, when the piston rod 32 of the second drive cylinder 3 extends, the seal ring 12 of the partition plate 11 is pressed against the valve seat surface 4 as shown in FIG. Since the seal ring 12 is in contact with the valve seat surface 4 around the outer periphery of the gate port 5, the flow of the fluid at the gate port 5 is shut off.
Thus, a series of valve closing operations of the first and second driving operations performed as shown in FIGS. 1 to 3 are performed by the compressed air supplied to the two cylinders 2 and 3 from one ascending port 27. .

Next, when opening the closed gate valve 1 as shown in FIG. 3, the switching valve (not shown) is switched to supply compressed air from the retreat port 34 of the second drive cylinder 3. (Arrow). The compressed air supplied from the retreat port 34 into the cylinder tube 30 pressurizes the piston 31 from the front (left side in the drawing) and moves the piston 31 backward, thereby retreating the piston rod 32. Therefore, the lower end of the valve rod 13 is pulled and swings like a lever, and the seal ring 12 of the partition plate 11 fixed to the upper end is separated from the valve seat surface 4 as shown in FIG.

At this time, the compressed air supplied from the retreat port 34 is first formed in the same chamber because the V-shaped seal packing 35 is in contact with the tapered portion of the piston rod 32 for sealing as shown in FIG. The flow to the discharged port 36 is blocked. However, when the piston 31 retreats to the position shown in FIG. 2, the seal packing 35 separates from the tapered portion of the piston rod 32, and the compressed air flows to the discharge port 36 side. Therefore, as in the case of closing the valve, the compressed air supplied from one place first pressurizes the piston 31 to perform a second drive to separate the partition plate 11 from the valve seat surface 4 and further supplies the same from the same place. The subsequent first drive is performed by the compressed air that has been generated.

From the retreat port 34 to the second drive cylinder 3
Is discharged from the discharge port 36 formed in the same chamber, and is supplied to the lowering port 28 of the first drive cylinder 2 (arrow). The compressed air thus supplied from the descending port 28 presses the piston 22 down from above by pressing it upward. Then, as the piston 22 descends, the piston rod 23 extends, and the position of the second drive cylinder 3 fixed to its lower end is lowered (arrow).
Accordingly, the lower end of the valve rod 13 is pulled downward, the slider 14 slides on the rail 15, and the partition plate 11 descends to the retracted position where it comes off the gate port 5 as shown in FIG.

Therefore, according to the gate valve 1 of the present embodiment, when the second drive cylinder 3 is moved up and down by driving the first drive cylinder 2, the valve body rod 13 is also moved up and down in the same direction together with the slider 14 supported by the shaft. When the partition plate 11 performs the first drive and the second drive cylinder 3 is driven in the shut-off position, the valve body rod 13 swings like a lever about the axis with the slider 14 as a lever, and the seal ring of the partition plate 11 12 comes into contact with and separates from the valve seat surface.
Thus, the structure for driving the first and second valve bodies can be simplified, and the size can be reduced. Also,
Compressed air supplied from one location at both valve closing and valve opening time
Since the supply to the other cylinder is performed by the mechanical operation of one cylinder, the control of the opening / closing operation of the valve element performed in two stages can be simplified.

Next, a second embodiment of the gate valve according to the present invention will be described. 5 to 7 are cross-sectional views showing the gate valve of the present embodiment, and show a state until the valve is closed from FIG. 1 to FIG. 3 (a state until the valve is opened from the reverse). FIG. 8 is a front view of the gate valve of the present embodiment, showing a closed state corresponding to FIG. Also in this gate valve 51, the first drive cylinder 5
2 and the second drive cylinder 53 are provided, but are arranged upside down as compared with the first embodiment.

Therefore, the gate valve 51 is connected to the partition plate 61 and the T
The lower end of the valve rod 62 fixed so as to form a letter is pivotally supported by the first drive cylinder 52, and is rocked by the second drive cylinder 53 via a rail groove 63 formed on the side surface. It has become. Specifically, the lower end of the valve body rod 62 is pivotally supported by a bracket 65 fixed to a piston rod 73 of the first drive cylinder 52, and the piston rod 8 of the second drive cylinder 53 is provided in the rail groove 63.
A roller 67 fixed to the end of the third roller 3 is inserted. The first drive cylinder 52 and the second drive cylinder 53 are
Since the first drive cylinder 2 and the second drive cylinder 3 of the first embodiment have substantially the same configuration, detailed description thereof will be omitted.

Next, the opening / closing operation of the gate valve 51 will be described. First, when closing the opened gate valve 51 as shown in FIG.
Compressed air is supplied from the ascending port 71 (arrow). The compressed air supplied into the cylinder tube 70 presses the piston 72 from below by pushing it up, and the piston rod 73 is pulled up with the rising piston 72 (arrow). Then, the valve body rod 62 with its lower end pivotally mounted is raised while being supported by the rail groove 63 in a state of being raised, and the partition plate 61 is arranged at the height of the gate port 5 as shown in FIG.

Subsequently, the compressed air driving the first drive cylinder 52 flows out of the discharge port 74 and is supplied to the second drive cylinder 53 (arrow). In the supply of the compressed air, the small-diameter portion 73a is provided at the rod packing 75 at the stroke end of the piston 72, as in the first embodiment, so that the first drive cylinder 52 and the second drive cylinder 53 are operated stepwise. (Fig. 2). Therefore, the compressed air is supplied from the discharge port 74 to the retraction port 81 of the second drive cylinder 53 when the valve element is raised. Therefore, the compressed air supplied from one location first performs a first drive in which the piston 72 is pressurized to raise the partition plate 61 to the shut-off position, and the second drive continued by the compressed air supplied from the same location. Is executed.

Then, when compressed air is also supplied to the second drive cylinder 53, the piston 82 is pressurized and slides backward (to the right in the drawing) together with the piston rod 83 (arrow). Therefore, the valve rod 62 is pulled through the roller 67, swings around the lower end as a fulcrum, and the seal ring 64 of the partition plate 61 is pressed against the valve seat surface 4 as shown in FIG. Since the seal ring 64 is in contact with the valve seat surface 4 around the outer periphery of the gate port 5, the flow of the fluid at the gate port 5 is interrupted. In this manner, a series of valve closing operations of the first and second driving operations performed as shown in FIGS. 5 to 7 are performed by the compressed air supplied from the one ascending port 71 to both the cylinders 52 and 3. .

Next, when opening the closed gate valve 51 as shown in FIG. 7, the switching valve (not shown) is switched to supply compressed air from the forward port 84 of the second drive cylinder 53. Done (arrow). The compressed air supplied from the forward port 84 into the cylinder tube 80 pressurizes the piston 82 from the rear (the right side in the drawing) and moves the piston 82 forward so that the piston rod 83 projects further. for that reason,
The valve rod 62 swings about the lower end as a fulcrum, and the seal ring 64 of the partition plate 61 fixed to the upper end is separated from the valve seat surface 4 as shown in FIG.

At this time, as shown in FIG. 5, the compressed air supplied from the forward port 84 is discharged in the same chamber because the V-shaped seal packing 85 is in contact with the piston rod 83 to seal the compressed air. The flow to the port 86 is blocked. However, when the piston 82 advances to the position shown in FIG.
5 is released, and the compressed air flows to the discharge port 86 side. Therefore, the compressed air supplied from one place first pressurizes the piston 82 to perform a second drive to separate the partition plate 61 from the valve seat surface 4, and further performs the second drive by the compressed air supplied from the same place. One drive is performed.

The compressed air supplied from the retreat port 84 to the second drive cylinder 53 flows out from the discharge port 86 formed in the same chamber, and is supplied to the lower port 75 of the first drive cylinder 52. (Arrow). The compressed air supplied from the descending port 75 presses the piston 72 down from above by pressing it upward. Then, the piston rod 73 extends (arrow) with the lowering of the piston 72, and the valve body rod 62, the lower end of which is axially mounted, is fitted into the rail groove 6
3, the partition plate 61 is lowered while being supported in an upright state, and the partition plate 61 is returned to the retracted position shown in FIG.

Therefore, according to the gate valve 51 of this embodiment, the piston rod 7 is driven by the driving of the first drive cylinder 52.
3 expands and contracts, the valve body rod 62 moves up and down along the rail groove 63, the partition plate 61 performs the first drive, and the second drive cylinder 53 is driven in the shut-off position, whereby the rail groove 6
3, the valve rod 62 swings via the roller 67 and the seal ring 64 comes into contact with and separates from the valve seat surface 4, so that the two cylinders 52 and 53 move the valve body to the first position. Further, the structure for the second driving can be simplified, and the size can be reduced. Further, the compressed air supplied from one location is supplied to the other cylinder by the mechanical operation of one cylinder at the time of valve closing and valve opening, so that the control of the opening / closing operation of the valve element performed in two stages is performed. Simplified.

It should be noted that the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the spirit of the present invention. For example, in the gate valves 1 and 51, both cylinders are arranged below the gate port 5, and the valve body is lowered to the retreat position and raised to the shut-off position. A second drive cylinder,
Furthermore, if the relationship between the gate openings is correct, the gate opening is not restricted in the vertical direction or the like.

[0040]

According to the present invention, there is provided a first drive cylinder having a piston rod protruding downward, and a first drive cylinder fixed to the piston rod and capable of moving up and down by driving the first drive cylinder. A second drive cylinder that expands and contracts in a direction perpendicular to the seating surface; and a valve body that is pivotally supported by a piston rod of the second drive cylinder and that is pivotally supported by a slider that can slide vertically in the middle. Is provided, so that it is possible to provide a small gate valve having a simplified structure.

The present invention also provides a first drive cylinder having a piston rod protruding downward, and a second drive disposed above the first drive cylinder and extending and retracting the piston rod in a direction perpendicular to the valve seat surface. A cylinder and a piston rod side of the first drive cylinder.
Since the valve body is provided at the upper end of the valve body rod provided with the rail groove in which the roller provided on the piston rod of the drive cylinder is provided, it is possible to provide a small gate valve having a simplified structure. It has become possible.

Further, the present invention uses two cylinders because the working fluid supplied from one place is supplied to the other cylinder by the mechanical operation of one cylinder both when the valve is closed and when the valve is opened. Thus, the control of the opening / closing operation of the valve element performed in two stages could be simplified.

[Brief description of the drawings]

FIG. 1 is a sectional view of a gate valve according to a first embodiment of the present invention when the valve is opened.

FIG. 2 is a sectional view of the gate valve according to the first embodiment of the present invention in the middle of operation.

FIG. 3 is a cross-sectional view showing the first embodiment of the gate valve according to the present invention when the valve is closed.

FIG. 4 is a front view of the gate valve according to the first embodiment of the present invention when the valve is closed.

FIG. 5 is a cross-sectional view of a gate valve according to a second embodiment of the present invention when the valve is opened.

FIG. 6 is a sectional view in the middle of operation showing a second embodiment of the gate valve according to the present invention.

FIG. 7 is a cross-sectional view of a gate valve according to a second embodiment of the present invention when the valve is closed.

FIG. 8 is a front view of a gate valve according to a second embodiment of the present invention when the valve is closed.

FIG. 9 is a view showing a first conventional example of a gate valve.

FIG. 10 is a view showing a second conventional example of a gate valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gate valve 2 1st drive cylinder 3 2nd drive cylinder 11 Partition plate 12 Seal ring 13 Valve rod 14 Slider 15 Rail 20 Cylinder tube 23 Piston rod 27 Up port 28 Down port 29 Drain port 30 Cylinder tube 32 Piston Rod 33 Forward port 34 Reverse port 36 Discharge port

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H053 AA25 BA23 DA12 3H081 BB01 BB03 CC23 DD18 DD26 DD28 EE02 FF26 HH05 3H089 AA77 BB27 CC01 CC12 CC15 GG01 JJ20

Claims (3)

[Claims] A first drive for raising and lowering a valve body for opening and closing a gate between a blocking position in front of the gate opening and a retreating position lowered from the blocking position; A gate valve operated in two stages of a second drive for contacting and separating from a valve seat surface of a mouth opening, a first drive cylinder having a piston rod protruding downward, and being fixed to the piston rod. A second drive cylinder that can be raised and lowered by driving a first drive cylinder, and that expands and contracts a piston rod in a direction perpendicular to the valve seat surface; and a second drive cylinder that is axially supported by the piston rod of the second drive cylinder. A gate valve, wherein a valve body is provided at an upper end of a valve body rod supported by a vertically slidable slider. 2. A first drive for raising and lowering a valve body that opens and closes a gate between a blocking position in front of the gate opening and a retreating position lowered from the blocking position, and the gate being moved at the blocking position. In a gate valve operated in two stages of a second drive for contacting and separating from a valve seat surface of an opening, a first drive cylinder having a piston rod protruding downward, and a first drive cylinder being provided above the first drive cylinder. A second drive cylinder disposed and extending and retracting a piston rod in a direction perpendicular to the valve seat surface; and a second drive cylinder pivotally supported on the piston rod side of the first drive cylinder.
A gate valve, wherein a valve body is provided at an upper end of a valve body rod provided with a rail groove in which a roller provided on a piston rod of the second drive cylinder is provided on the way. 3. The gate valve according to claim 1, wherein the first drive cylinder includes an ascending port and a descending port for supplying a working fluid that moves a piston up and down.
A discharge port for discharging the working fluid supplied from the ascending port at the stroke end of the piston rod,
The piston rod has a small-diameter portion that is not in contact with a rod packing provided between an ascending port and an exhaust port at a stroke end. The second drive cylinder moves the piston back and forth. A forward port and a backward port for supplying a working fluid to be operated,
A discharge port for discharging the working fluid supplied from the forward port or the reverse port after the operation of the piston,
A seal packing provided between the forward or backward port and the discharge port comes into non-contact with the piston rod after the operation of the piston, and the discharge port of the first drive cylinder and the second The forward or backward port of the drive cylinder is connected,
A gate valve, wherein a discharge port of the second drive cylinder and a lowering port of the first drive cylinder are connected.