JP2002310307A - Valve structure for shut-off valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve structure for a shut-off valve having a small size and vacuum retaining capability. SOLUTION: The valve structure for the shut-off valve comprises an annular groove 33 circulated on one side face of a valve disc opposed to a valve seat and a seal member 34 fitted to the annular groove 33. The seal member 34 has a base and a swollen portion 206 molded integrally with the base. The swollen portion 206 has a fist recess 202 and a second recess 204 on the side of the base so that the swollen portion 206 is deflected to the side of second recess 204 and pressed against the valve seat during sealing of the seal member 34 to secure a wide shut-off plane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer passage for transferring a work such as an integrated circuit (IC) or a part thereof from one vacuum processing chamber to another vacuum processing chamber. The present invention relates to a valve structure of a shutoff valve that opens and closes a flow passage or an exhaust passage.

[0002]

2. Description of the Related Art Conventionally, for example, in a processing apparatus for a semiconductor wafer, a liquid crystal substrate, or the like, a semiconductor wafer, a liquid crystal substrate, or the like is taken in and out of various processing chambers through passages. Are each provided with a gate valve for opening and closing the passage.

This gate valve is disclosed, for example, in Japanese Patent No.
As shown in US Pat. No. 13171 (US Pat. No. 5,415,376 and US Pat. No. 5,641,149), after the valve disc reaches the position opposing the valve seat by the linear motion of the valve rod displaced under the driving action of the cylinder, The valve disc is pressed against the valve seat by the tilting motion of the valve rod and is seated, so that the passage formed in the valve box is closed. That is, as shown in FIGS. 13 and 14, the gate valve 1 according to the related art includes a valve box 3 in which a passage 2 for taking in and out a work is formed, and a valve seat 4 formed in the valve box 3. And a valve rod 6 connected to the valve disk 5 so as to be vertically movable and tiltable.

A block 7 is connected to an upper portion of the valve rod 6, and guide grooves 10 (see FIG. 1) formed on both sides of the cylinder tube 9 of a pair of cylinders 8a and 8b are formed on both sides of the block 7. 14) is fixed, and the block 7 is provided so as to move up and down and tilt under the guiding action of the guide groove 10 with which the pivot 11 engages. The cylinder tube 9, the block 7 and the pivot 11 are each formed of a metal material.

In other words, the block 7 has a pivot 11
Under the guide action of the guide groove 10 in which
Linearly moves along the vertical direction integrally with the yoke 13 through the lower end 1 of the guide groove 10.
0a (see FIG. 15) is provided so as to tilt in the direction of arrow A with the pivot 11 supported by the fulcrum as a fulcrum. Accordingly, the valve disc 5 is tilted in the direction of arrow B with the pivot 11 as a fulcrum and seated on the valve seat 4,
The passage 2 is hermetically closed (see FIG. 13).

In FIG. 13, reference numeral 14 denotes a plate-like cam having an inclined surface formed by a rhombus in cross section. The inclined surface of the plate-like cam 14 is displaced in a substantially horizontal direction, whereby A structure is employed in which the block 7 tilts in the direction of arrow A about the lower end 10a of the guide groove 10 as a fulcrum.

Particularly, in this case, the sealing member 16 fitted in the groove of the valve disk 5 shown in FIG. 13 has an O-ring structure. It was necessary to strongly press the valve disc 5 against the valve seat 4.

[0008]

However, in the gate valve according to the prior art, since the pivot of the block is slidably displaced along the guide groove formed on the side surface of the cylinder, it has been required for many years. There is a disadvantage that the pivot is worn and deformed by use, and the guiding function is reduced.

In addition, in the gate valve according to the prior art, the number of parts is increased by providing pivots on both sides of the valve block, and a step of forming a guide groove on the side surface of the cylinder is required, so that the manufacturing cost is increased. There is an inconvenience.

Further, in the gate valve according to the prior art, there is a possibility that dust or the like is generated due to the sliding displacement of the pivot of the block made of metal material along the guide groove of the cylinder tube made of metal material. is there. In other words, dust may be generated due to friction between the metallic materials, and it is difficult to use in an environment requiring cleanliness such as a clean room.

In particular, according to the conventional valve structure in which sealing is ensured by an O-ring fitted to the valve disc, it is necessary to strongly press the valve disc against the valve seat in order to enhance the sealing. In order to secure the rigidity of the cylinder and the like, it must be made robust, and there are disadvantages such as an increase in weight and an increase in manufacturing cost.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned disadvantages, and has improved sealing performance without pursuing rigidity of a gate valve by improving the shape of a sealing member fitted to a valve disk. It is another object of the present invention to provide a valve structure of a shut-off valve which is small and economical to manufacture.

[0013]

In order to solve the above-mentioned problems, the present invention provides a shut-off valve in which a circumferential groove is provided on one side of a valve disk facing a valve seat, and a sealing member is fitted in the groove. In the valve structure, the seal member includes a base and a bulge formed integrally with the base, and the bulge has a first recess and a second recess on the base side. When the sealing member is sealed, the bulging portion is bent toward the second concave portion and pressed against the valve seat.

With such a shape, the bulging portion of the seal member can be raised in the direction facing the valve seat. When the sealing member is pressed against the valve seat, the bulging portion is largely bent toward the second concave portion,
An area (blocking surface) of the seal member that comes into pressure contact with the valve seat can be ensured wider than that of the conventional seal member, and the sealing property can be improved.

[0015] In this case, between the first arc portion formed from the deepest portion of the first concave portion to the vertex of the bulging portion, the end surface of the first arc portion is moved from the vertex to the vertex of the first arc portion. A vertical line a drawn on the basis of a central imaginary line perpendicular to the bottom surface of the groove, and a vertical line a extending from the deepest portion of the second concave portion to the vertex, extending in a direction opposite to the line a. 2
It is preferable that the relationship with the vertical line b drawn to reach the end face of the circular arc portion is a> b.

In this case, when the seal member is pressed against the valve seat, the mass of the bulging portion on the side of the second concave portion is smaller than the mass of the bulging portion on the side of the first concave portion. Therefore, even if the seal member is not strongly pressed, the bulging portion on the second concave side can be bent to deform the seal member.

The first arc portion includes a first straight line portion, and is formed between a first imaginary line extending from the first straight line portion to the central imaginary line and the central imaginary line. Angle θ
The second arc portion includes a second straight line portion, and is formed between the second imaginary line extending from the second straight line portion to the center imaginary line and the center imaginary line. Angle θ2
In this case, the same effect as described above can be obtained when θ1> θ2. In this case, the angle θ2 is θ2 ≦ 10 °
It is preferred that

Further, a distance c between the deepest portion of the first concave portion parallel to the virtual center line and the bottom surface, and a distance d between the deepest portion of the second concave portion parallel to the virtual center line and the bottom surface. It is desirable that the relationship with c satisfies c ≧ d.

When such a condition is satisfied, the second
Since the length of the circular arc portion is equal to or greater than the length of the first circular arc portion, the second circular arc portion is easily bent, and is reliably bent toward the second concave portion. Can be.

The seal member may be made of rubber.
By using rubber, the flexibility can be increased, the durability can be improved, and the sealing area can be further improved by increasing the blocking area.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The valve structure of a shut-off valve according to the present invention will be described in detail with reference to preferred embodiments.

First, the structure of the gate valve related to the present invention will be described, and then the shape of the sealing member will be mentioned.

In FIG. 1, reference numeral 20 indicates a gate valve. The gate valve 20 includes a driving unit 22 and
A pair of valve rods 24a and 24b which are displaced in the vertical direction under the driving action of the driving unit 22 and tilt in a direction substantially perpendicular to the vertical direction;
a, 24b having a generally rectangular valve disk 26 connected to one end thereof. An annular stepped portion 2 is provided on one end side of the valve rods 24a and 24b and on the outer peripheral surface at a substantially central portion, respectively.
7a and 27b are formed (see FIG. 3).

A valve box 30 having a passage 28 for taking in and out a work (not shown) is provided on the upper side of the drive section 22 (see FIGS. 7 and 12). When the valve disc 26 is seated on the valve seat 32 formed on the wall surface, the passage 28 is airtightly closed. A rectangular annular groove 33 is formed in the valve disk 26 so as to face the valve seat 32, and a seal member 34 is mounted in the annular groove 33. When the valve disc 26 is seated on the valve seat 32 by the seal member 34, airtightness is maintained. The structure of the seal member 34 will be described later.

The drive unit 22 includes a base plate 38 fixed to the bottom surface of the valve box 30 via a screw member 36 (see FIG. 3), a bottomed cylindrical casing 40 mounted on the base plate 38, A cylinder mechanism (drive source) 42 disposed in the casing 40.

As shown in FIG. 2, the base plate 38 is formed with a pair of through-holes 44a, 44b having a substantially circular cross section for inserting a pair of valve rods 24a, 24b. The lower surface has a concave portion 4 having a semicircular cross section for supporting a support roller (support member) 46 described later.
8 (see FIG. 1). The through hole 44a,
The diameter of the valve rod 44a is slightly larger than the diameter of the valve rods 24a, 24b, and the through-holes 44a, 44b hold one end of a bellows 50 that covers a predetermined portion of the valve rods 24a, 24b. 52 is fitted.

Between the bellows 50 and the valve box 30,
As shown in FIG. 3, a packing (seal member) 51 surrounding the outer peripheral surfaces of the valve rods 24a and 24b is sandwiched,
When the piston 60 reaches the top dead center or the bottom dead center, which is the displacement end position, the packing 51 moves the valve rod 24a,
It contacts the upper annular step 27a or the lower annular step 27b of 24b to perform a sealing function. The packing 51 is provided so as not to come into contact with the outer peripheral surfaces of the valve rods 24a and 24b when the piston 60 is located between the top dead center and the bottom dead center, so that generation of dust due to friction is prevented. Is done.

Also, the base plate 38 has
As shown in FIG. 2, for example, a first buffer member 53 formed of a resin material such as urethane resin or polyurethane resin is mounted in the hole, and the first buffer member 53 is provided.
Is fixed in the hole through the metal fitting 55 and the retaining ring 57. The first cushioning member 53 includes a support roller 46 provided in the recess 4.
When engaged with the support roller 8, the support roller 46 comes into contact with the support roller 46 and functions to absorb the impact of the support roller 46.

As shown in FIG. 3, the cylinder mechanism 42 has convex portions 54 (see FIG. 2) projecting outward on both side surfaces, and is formed on the base plate 38 via a screw member (not shown). One end is fixed to a cylinder tube 56, a piston 60 movably housed along a cylinder chamber 58 in the cylinder tube 56, and one end is connected to the piston 60, and is axially attached to the outer peripheral surface. A piston rod 64 having a spline groove 62 extending along the same; a spline bearing member 68 fixed to the cylinder tube 56 and provided with a plurality of balls 66 engaged with the spline groove 62 of the piston rod 64; Having.

A piston packing 70 for airtightly holding an upper cylinder chamber 58a and a lower cylinder chamber 58b, which are divided into two parts by the piston 60, is mounted on the outer peripheral surface of the piston 60. When the piston 60 reaches the bottom dead center, a second cushioning member 72 that contacts the upper end of the spline bearing member 68 and absorbs the shock when the piston 60 reaches the bottom dead center. The second buffer member 72 is preferably formed of a resin material such as urethane resin or polyurethane resin.

A pressure fluid (for example, compressed air) is supplied to the upper cylinder chamber 58a and the lower cylinder chamber 58b through a tube (not shown) connected to a pressure fluid supply source (not shown). The pressure fluid is supplied to either the upper cylinder chamber 58a or the lower cylinder chamber 58b under the switching action of a switching valve (not shown).

Further, as shown in FIGS. 2 and 3, the drive unit 22 includes a lock nut 74 and a spacer 76.
A lever member (first displacement member) 78 fixed to the other end of the piston rod 64 via the second member, and a displacement member (second displacement member) 80 that is displaced integrally with the lever member 78.

A pair of projecting pieces 82a and 82b projecting a predetermined length in the lateral direction are formed on both side surfaces of the lever member 78 extending substantially in parallel.
A substantially circular recess 86 to which one end of a spring member 84 described later is engaged is formed in 82b. On both sides of the lever member 78, an elongated hole 88 cut out in a substantially oval shape.
a, 88b are respectively formed, and the long holes 88a, 88b are formed.
A roller 92 fixed to the displacement member 80 via the pin member 90 is provided at b.

Further, a pair of pin members 94 are fitted to upper portions of both side surfaces of the lever member 78 through holes.
One end of the pin member 94 is provided to engage with an engagement groove 96 formed on both side surfaces of the displacement member 80.

As shown in FIGS. 2 and 3, a pair of flange portions 98a, 98b projecting a predetermined length in the lateral direction are provided on both sides of the displacement member 80 extending substantially in parallel.
Is formed. The flange portions 98a and 98b are formed with a hole 100 having a substantially circular cross section into which the other ends of the valve rods 24a and 24b are inserted.
The valve rods 24a, 24b are fixed to the displacement member 80 via lock nuts 102, which are fastened to the threaded portions of the valve members 24a, 24b.

A pair of flanges 98 of the displacement member 80
a, 98b and a set of projecting pieces 82a, 8 of the lever member 78.
2b, a spring member 84 is interposed, respectively.
One end of the spring member 84 has flanges 98a, 98
b is fixed to one end of the valve rods 24a, 24b fixed to the other end of the valve rod 24a, 24b.
b is engaged with the circular concave portion 86.

A bellows 50 is provided at the other end of the valve rods 24a, 24b so as to cover the outer peripheral surface thereof.
8 is rotatably connected to a ring body 52 held by the ring body 8, and the other end of the ring body 1 is externally fitted to the valve rods 24a and 24b.
04.

On both side surfaces of the displacement member 80, engagement groove portions 96 are formed, each of which is engaged with one end of a pin member 94 locked on the lever member 78. When the pin member 94 is engaged with the lower end 96a of the engagement groove 96, the lever member 78 and the displacement member 80 are moved in the up-down direction and the front-back direction (in FIG. 3, a direction substantially orthogonal to the plane of the drawing).
Are positioned in a state where they are separated from each other by a predetermined distance in the vertical direction, and move up and down integrally in such a state. Then, the pin member 94 is separated from the lower end 96a of the engagement groove 96, and the inclined portion 96 is removed.
By rising along b (see FIG. 2), the valve disc 26 can be tilted.

Further, a pair of support rollers 46 is rotatably supported on the upper part of the bifurcated displacement member 80,
The support roller 46 is inserted into the curved concave portion 48 of the base plate 38 at the displacement end position of the displacement member 80 (see FIG. 1), and the support roller 4 engaged with the concave portion 48 is provided.
6, the valve disk 26, the valve rods 24a, 2
4b and the displacement member 80 tilt by a predetermined angle θ (see FIG. 11).

Further, a piston rod 64 is inserted through the lower portion of the displacement member 80 to form an elongated hole 10 having an elliptical cross section.
6, the piston rod 64 is provided so as to be displaced along the elongated hole 106 when the displacement member 80 is tilted (see FIG. 5).

Here, the seal member 34 will be described in detail. The seal member 34 has a base 200 and a bulging portion 206 integrally formed of rubber, preferably synthetic rubber, for example, silicon rubber, and the base 200 is firmly held in the annular groove 33. The bulging part 206 is shown in FIG.
As will be understood from FIG. 2, the first base portion 200 has a first concave portion 202 and a second concave portion 204 which are formed to protrude in an arc shape toward the valve seat 32 and are curved with the base portion 200. Then, the first arc portion 21 extending from the deepest portion 214 to the apex 208 to form the first concave portion 202 is formed.
8 is formed, and a second concave portion 216 extending from the deepest portion 216 to the apex 208 to form the second concave portion 204 is formed.
Are formed. An imaginary center line 212 orthogonal to the bottom surface 210 of the annular groove 33 is drawn from the vertex 208 of the bulging portion 206. The first arc portion 21 is located between the apex 208 and the deepest portion 214 of the first concave portion 202.
When the vertical line a is drawn with respect to the end imaginary line 8 with respect to the central imaginary line 212, the vertical line a extends in the opposite direction from the central imaginary line 212 and
It is longer than the vertical line b leading to the 0 end face. In other words, the first circular arc portion 218 is set to have a larger mass than the second circular arc portion 220 with respect to the central imaginary line 212. The straight line c between the deepest portion 214 of the first concave portion 202 parallel to the virtual center line 212 and the bottom surface 210 is the deepest portion of the second concave portion 204 parallel to the virtual center line 212. It is set to be larger than a straight line d between the portion 216 and the bottom surface 210.

In this case, the first arc portion 218 is
The first imaginary line 2 extending to the center imaginary line 212 by extending the first straight portion 218a
The angle formed between the imaginary line 212 and the central imaginary line 212 is θ1, and the second arc 220 is
0a, and the angle formed between the second virtual line 224 extending to the central virtual line 212 by extending the second linear portion 220a and the central virtual line 212 and the central virtual line 212 is θ2, the angle θ1 May be set to be larger than the angle θ2. If the angle θ2 is set to be smaller than or equal to 10 °, the blocking property is excellent and it is preferable.

In the embodiment of the present invention, the seal member 34 is fitted so that the second concave portion 204 is inside the annular groove 33 (see FIGS. 8 and 9). On the contrary, even if the second concave portion 204 is fitted so as to be outside the annular groove 33 as shown by a broken line, a predetermined sealing effect can of course be obtained.

The operation and operation and effect of the shut-off valve configured as described above will be described. In the following description,
Piston 60 is at the lowermost position of cylinder chamber 58 (bottom dead center)
And the passage 28 formed in the valve box 30 has the valve disc 2
An open state that is not closed by 6 will be described as an initial position.

In this case, in the initial position, the spring member 8
Since the lever member 78 is pressed downward by the resilience of the lever 4, the pin member 94 fixed to the lever member 78 is moved to the lower end 96 of the engagement groove 96 of the displacement member 80.
a. In the initial position,
Long holes 88a, 88 formed on both side surfaces of the lever member 78
The roller 92 is in a state of being engaged with the upper part of the b.

In the initial position, a pressure fluid is supplied from a pressure fluid supply source (not shown) to the lower cylinder chamber 58b via a tube (not shown). The piston 60 moves under the action of the pressure fluid supplied to the lower cylinder chamber 58b.
Rises, and the piston rod 64 connected to the piston 60 also rises. In this case, it is assumed that the upper cylinder chamber 58a is open to the atmosphere under the action of a switching valve (not shown).

When the piston rod 64 is raised, the lever member 78 and the piston rod 64 are moved together.
The displacement member 80, the valve rods 24a and 24b, and the valve disk 26 rise integrally. In this case, the lever member 78
Is in a state of being pressed downward by the resilient force of the spring member 84, and a pair of pin members 94 fixed to both side surfaces of the lever member 78 are attached to the lower end 96 a of the engaging groove 96 of the displacement member 80. By being held, the lever member 78 and the displacement member 80 are positioned and held at predetermined positions in which the positional shift in the up-down direction and the front-back direction (in FIG. 3, the direction substantially orthogonal to the paper surface) is prevented. is there. Therefore, the lever member 78 and the displacement member 80 move up integrally while being positioned and held at the predetermined position.

When the piston rod 64 rises, a plurality of balls 66 roll and circulate along spline grooves 62 formed in the piston rod 64, and the piston rod 64 is fixed to the cylinder tube 56. The rotation in the circumferential direction is prevented by the spline bearing member 68 to prevent rotation.

The piston rod 64 rises and the displacement member 8
When one end of the contact member 0 comes into contact with the base plate 38, the displacement member 80 reaches the displacement end position, and the valve disk 26 is in a state of facing the opening of the passage 28 (FIG. 7).
reference). At this time, the supporting roller 46 provided on the upper part of the displacement member 80 is
And the shock is absorbed by contacting the first buffer member 53.

After the displacement member 80 reaches the displacement end position, the piston rod 64 further rises,
The displacement member 80 is provided with the long holes 88a, 88 of the lever member 78.
Under the action of the engagement of the roller 92 with the roller b, the support roller 46 engaging with the concave portion 48 is tilted by a predetermined angle θ, and the valve disk 26 is seated on the valve seat 32 to close the passage 28 (FIG. 12).

That is, after the displacement member 80 reaches the displacement end position, the piston rod 64 is further raised against the resilience of the spring member 84 to thereby increase the lever member 78.
Only the ascending, the displacement member 80 is moved by the lever member 7
Under the action of the roller 92 engaging the elongated holes 88a and 88b formed on both side surfaces of the support 8, the support roller 46 is tilted by a predetermined angle θ using the support roller 46 as a fulcrum (see FIG. 12). When the displacement member 80 is tilted about the support roller 46 as a fulcrum, the pin members 94 fixed to both side surfaces of the lever member 78 are separated from the lower end 96a of the engagement groove 96 of the displacement member 80 and are inclined. Rise along.

Accordingly, the valve disc 26 fixed to the displacement member 80 via the valve rods 24a and 24b is moved by the predetermined angle θ to move the passage 2
8 and is displaced substantially horizontally toward the passage 28 from a state in which they face each other at a predetermined interval. As a result, the valve disc 26
Is seated on the valve seat 32 so that the passage 28 is airtightly closed.

That is, as described above, the valve disk 26 is tilted by a predetermined angle θ about the support roller 46 engaged with the concave portion 48 as a fulcrum, so that the sealing member 34 provided on the valve disk 26 is provided. Is pressed by the valve seat 32 to be deformed and crimped, whereby the passage 28 is airtightly closed. In other words, because the first arc portion 218 side has a larger mass than the second arc portion 220 side, when pressed against the valve seat 32, as shown in FIG. It is bent and pressed against the valve seat 32. Therefore, the degree of close contact with the valve seat 32 is further increased.

Next, when the valve disk 26 is separated from the valve seat 32 to open the passage 28, the piston 60 is supplied by supplying a pressurized fluid to the upper cylinder chamber 58a under the switching action of a switching valve (not shown). Is lowered, and the piston rod 64, the lever member 78, and the displacement member 80 are integrally lowered to return to the initial position. In this case, the lower cylinder chamber 58b is open to the atmosphere under the action of a switching valve (not shown).

That is, the displacement member 80 has the long holes 88a, 8a
After the roller 92 is tilted by a predetermined angle θ in a direction opposite to the above direction under the action of the roller 92 engaging with the roller 8b, the lever member 78 and the displacement member 80 are integrated with the piston rod 64 to return to the initial position. . At this time, the shock when the piston 60 reaches the bottom dead center is absorbed by the second buffer member 72 provided on the bottom surface of the piston 60. When the piston 60 descends, the lever member 78 is pressed downward by the elastic force of the spring member 84, so that the flow rate of the pressurized fluid supplied to the upper cylinder chamber 58a can be suppressed. .

As described above, in this embodiment, the seal member 34 is pressed by the valve seat 32 while being deformed in shape. That is, the pressed and deformed shape bends toward the second arc portion 220 as shown by the line in FIG. 9, and the pressure contact surface of the valve seat 32 with respect to the first arc portion 218 rather than the first arc portion 218. Is widely seated (close contact).

Further, if the airtightly shielded passage 28 communicating with the second concave portion 204 is maintained at a positive pressure, the positive pressure causes the second concave portion of the seal member 34 to move. The side 204 can be crimped by the valve seat 32. Needless to say, a sufficient shielding effect can be obtained even when the passage 28 has a negative pressure and the periphery of the valve disk 26 is at a positive pressure, or when both the passage 28 and the periphery of the valve disk 26 are at a negative pressure or a positive pressure. .

[0058]

According to the present invention, by improving the shape of the sealing member, the sealing performance can be improved, the air-tightness maintaining ability can be enhanced, and the generation of dust and the like can be reduced as much as possible. It becomes possible. In addition, it is possible to improve the sealing performance without pursuing the rigidity of the gate valve, thereby making it possible to manufacture the gate valve compactly and economically.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a gate valve according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the gate valve shown in FIG.

FIG. 3 is a longitudinal sectional view taken along an axial direction of the gate valve.

FIG. 4 is a transverse sectional view taken along the line IV-IV of FIG. 3;

FIG. 5 is a transverse sectional view taken along the line VV of FIG. 3;

FIG. 6 is a transverse sectional view taken along the line VI-VI in FIG. 3;

FIG. 7 is a longitudinal sectional view taken along the line VII-VII in FIG. 3;

FIG. 8 is an enlarged view of a seal member fitted to the valve disc shown in FIG. 7;

FIG. 9 is an enlarged view showing a shape in which the seal member shown in FIG. 7 is deformed by being pressed by a valve seat.

10 is a longitudinal sectional view showing a state in which the valve rod is tilted by a predetermined angle θ from the state shown in FIG. 7 and is seated on the valve seat.

FIG. 11 is a partially enlarged longitudinal sectional view of a packing for sealing a valve rod.

FIG. 12 is a longitudinal sectional view of a base plate along a direction substantially orthogonal to an axis.

FIG. 13 is a longitudinal sectional view along the axial direction of a gate valve according to the related art.

14 is a longitudinal sectional view of the gate valve shown in FIG. 13 along the axial direction.

FIG. 15 is a perspective view of a cylinder tube constituting the gate valve shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 20 ... Gate valve 22 ... Drive part 24a, 24b ... Valve rod 26 ... Valve disc 28 ... Passage 30 ... Valve box 32 ... Valve seat 34 ... Seal member 38 ... Base plate 40 ... Casing 42 ... Cylinder mechanism 44a, 44b ...
Through hole 46 ... Support rollers 48, 86 ... Recess 50 ... Bellows 51 ... Packing 53, 72 ... Buffer member 56 ... Cylinder tube 58, 58a, 58b ... Cylinder chamber 60 ... Piston 62 ... Spline groove 64 ... Piston rod 66 ... Ball 68 ... Spline bearing member 70 ... Piston packing 78 ... Lever member 80 ... Displacement members 82a, 82b ...
Projecting piece 84: Spring member 88a, 88b,
106 ... long holes 90, 94 ... pin members 92 ... rollers 96 ... engagement grooves 98a, 98b ...
Flange part 200 Base part 202 First concave part 204 Second concave part 206 Swelling part 208 Top vertex 210 Bottom surface 212 Central phantom line 214 Deepest part of first concave part 216 Deepest part of second concave part Part 218 First arc part 218a First straight part 220 Second arc part 220a Second straight part 222 First virtual line 224 Second virtual line

Continued on the front page F term (reference) 3H053 AA02 AA25 AA31 BA04 BA22 BA34 DA09 3J006 AB01 AB13 CA01

Claims (6)

[Claims] 1. A valve structure of a shut-off valve in which a circumferential groove is provided on one side surface of a valve disk facing a valve seat, and a seal member is fitted into the groove, wherein the seal member is formed integrally with the base. A first concave portion and a second concave portion on the side of the base, and the second convex portion is formed when the sealing member is sealed. A valve structure for a shut-off valve, which is bent to the side and pressed against a valve seat. 2. The valve structure according to claim 1, wherein the first arc portion is formed between a first arc portion formed from a deepest portion of the first concave portion to a vertex of the bulging portion. With respect to the end surface, a vertical line a drawn from the apex with reference to a central imaginary line orthogonal to the bottom surface of the groove, and extending in a direction opposite to the line a from the deepest portion of the second concave portion A relationship between a vertical line b drawn to reach an end face of a second arc portion formed to the apex and a vertical line b satisfies a> b, wherein a> b. 3. The valve structure according to claim 1, wherein the first arc portion includes a first straight line portion, and a first imaginary line extending from the first straight line portion to the central imaginary line; An angle formed between the central imaginary line and the central imaginary line is θ1, a second imaginary line extending from the second imaginary line to the central imaginary line includes the second straight line portion in the second arc portion. And the angle formed between the imaginary line and the central imaginary line is θ2, θ1>
The valve structure of a shut-off valve, wherein the first arc portion and the second arc portion are formed so as to satisfy θ2. 4. The valve structure for a shut-off valve according to claim 3, wherein the angle θ2 satisfies θ2 ≦ 10 °. 5. The valve structure according to claim 1, wherein a distance c between a deepest portion of the first concave portion parallel to the central imaginary line and the bottom surface. And a distance d between a deepest portion of the second concave portion parallel to the virtual center line and the bottom surface satisfies c ≧ d, wherein c ≧ d. 6. The valve structure according to claim 1, wherein said seal member is formed of rubber.