JP4632111B2 - Valve structure of shut-off valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes, for example, a transfer passage for transferring a work such as an integrated circuit (IC) and its parts from one vacuum processing chamber to the other vacuum processing chamber, or a flow passage or an exhaust passage for pressure fluid, gas, etc. The present invention relates to a valve structure of a shut-off valve that opens and closes.
[0002]
[Prior art]
Conventionally, for example, in processing apparatuses such as semiconductor wafers and liquid crystal substrates, semiconductor wafers and liquid crystal substrates and the like have been taken in and out of various processing chambers through the passages. A gate valve for opening and closing the passage is provided.
[0003]
For example, as shown in Japanese Patent No. 2,613,171 (US Pat. No. 5,415,376, US Pat. No. 5,641,149), this gate valve is configured such that a valve disc is moved by a straight movement of a valve rod that is displaced under the operation of a cylinder. After reaching the opposite position, the valve disc is pressed against the valve seat by the tilting movement of the valve rod, and 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 prior 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. A valve disc 5 that closes the passage 2 by being seated on the valve disc, and a valve rod 6 that is connected to the valve disc 5 and is provided so as to be vertically movable and tiltable.
[0004]
A block 7 is connected to the upper portion of the valve rod 6, and guide grooves 10 formed on both side surfaces of the cylinder tube 9 of the pair of cylinders 8a and 8b are formed on both side surfaces of the block 7 (see FIG. 14). A pivot shaft 11 that is displaced along the guide shaft 10 is fixed, and the block 7 is provided to move up and down and tilt under the guide action of the guide groove 10 with which the pivot shaft 11 is engaged. The cylinder tube 9, the block 7 and the pivot 11 are each made of a metal material.
[0005]
In other words, the block 7 linearly moves along the vertical direction integrally with the yoke 13 via the tension spring 12 under the guiding action of the guide groove 10 with which the pivot 11 is engaged. It is provided so as to tilt in the direction of arrow A with the pivot 11 supported by the lower end 10a (see FIG. 15) being curved as a fulcrum. Therefore, the valve disc 5 tilts in the direction of arrow B with the pivot 11 as a fulcrum and is seated on the valve seat 4, so that the passage 2 is airtightly closed (see FIG. 13).
[0006]
In FIG. 13, reference numeral 14 indicates a plate-like cam having an inclined surface with a rhombus cross section, and the inclined surface of the plate-like cam 14 is displaced in a substantially horizontal direction, so that the block 7 is A structure that tilts in the direction of arrow A with the lower end portion 10a of the guide groove 10 as a fulcrum is employed.
[0007]
In particular, in this case, the seal member 16 fitted in the groove portion of the valve disk 5 shown in FIG. 13 has an O-ring structure, and in order to enhance the sealing performance when the passage 2 is closed, the valve disk 5 It was necessary to press strongly against the valve seat 4.
[0008]
[Problems to be solved by the invention]
However, the gate valve according to the prior art is configured such that the pivot of the block slides and displaces along the guide groove formed on the side surface of the cylinder. However, there is a drawback that the guide function is lowered.
[0009]
Further, in the gate valve according to the prior art, by providing pivots on both sides of the valve block, the number of parts is increased, and a process of forming guide grooves on the side surface of the cylinder is required, resulting in an increase in manufacturing cost. is there.
[0010]
Further, in the gate valve according to the conventional technique, dust or the like may be generated by 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. In other words, dust may be generated due to friction between metal materials, and it is difficult to use in an environment where cleanliness is required such as a clean room.
[0011]
In particular, according to the valve structure that ensures the sealing performance by the O-ring fitted to the conventional valve disk, it is necessary to strongly press the valve disk against the valve seat in order to improve the sealing performance. In order to ensure the rigidity of the sheet, it must be made robustly, resulting in inconveniences such as an increase in weight and an increase in manufacturing cost.
[0012]
The present invention has been made to overcome the above disadvantages, and by improving the shape of the seal member fitted to the valve disc, the sealing performance is improved without pursuing the rigidity of the gate valve, and the compact size is improved. It aims at providing the valve structure of the shut-off valve which can be manufactured economically by.
[0013]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a valve structure of a shut-off valve in which a groove that circulates is provided on one side surface of a valve disk that faces a valve seat, and a seal member is fitted in the groove. A base and a bulge formed integrally with the base. The bulge has a first recess and a second recess on the base, and the swell is formed when the seal member is sealed. The protruding portion is bent toward the second concave portion and is pressed against the valve seat.
[0014]
If it makes such a shape, the said bulging part of the said sealing member can be made high in the direction which opposes a valve seat. When the sealing member is pressed against the valve seat, the bulging portion is greatly bent toward the second concave portion, so that the area of the sealing member that presses against the valve seat (blocking surface) is compared with the conventional sealing member. In comparison, it can be secured widely, and its sealing performance can be improved.
[0015]
In this case, between the first arc portion formed from the deepest portion of the first recess to the apex of the bulging portion, the bottom surface of the groove from the apex to the end surface of the first arc portion A vertical line a drawn on the basis of a central imaginary line orthogonal to the second arc, and a second arc extending from the deepest part of the second recess to the apex extending in the opposite direction to the line a It is preferable that the relationship with the vertical line b drawn so as to reach the end face of the part is a> b.
[0016]
In this case, when the seal member is pressed against the valve seat, the mass of the bulging portion on the second concave portion side is smaller than the mass of the expanding portion on the first concave portion side. Therefore, even if the seal member is not strongly pressed, the bulge portion on the second recess side can be bent to deform the seal member.
[0017]
The first arc portion includes a first straight line portion, and an angle formed between the first virtual line extending from the first straight line portion to the central virtual line and the central virtual line is θ1. And the second arc portion includes a second straight line portion and is formed between the second virtual line extending from the second straight line portion to the central virtual line and the central virtual line. When the angle is θ2, the same effect as described above can be obtained even when θ1> θ2. In this case, it is preferable that the angle θ2 is θ2 ≦ 10 °.
[0018]
Furthermore, the relationship between the distance c between the deepest portion of the first recess parallel to the central imaginary line and the bottom surface and the distance d between the deepest portion of the second recess parallel to the central imaginary line and the bottom surface. However, it is preferable to satisfy c ≧ d.
[0019]
When such a condition is satisfied, the length of the second arc portion is equal to or greater than the length of the first arc portion, so that the second arc portion is easily bent and reliably. Can be bent toward the second recess.
[0020]
The sealing member may be made of rubber. By using rubber, flexibility can be improved, durability can be improved, and a blocking area can be increased to further improve sealing performance.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
The valve structure of the shut-off valve according to the present invention will be described in detail below with reference to preferred embodiments.
[0022]
First, the structure of the gate valve related to the present invention will be described, and then the shape of the seal member will be mentioned.
[0023]
In FIG. 1, reference numeral 20 indicates a gate valve. The gate valve 20 includes a drive unit 22 and a pair of valve rods 24a and 24b that are displaced in the vertical direction under the driving action of the drive unit 22 and tilt in a direction substantially orthogonal to the vertical direction. A substantially rectangular valve disk 26 connected to one end of the valve rods 24a, 24b. Annular step portions 27a and 27b are formed on the outer peripheral surfaces of the one end side and the substantially central portion of the valve rods 24a and 24b, respectively (see FIG. 3).
[0024]
A valve box 30 having a passage 28 for taking in and out a workpiece (not shown) is provided on the upper side of the drive unit 22 (see FIGS. 7 and 12) and formed on the inner wall surface of the valve box 30. When the valve disc 26 is seated on the valve seat 32, 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 attached to the annular groove 33. When the valve disk 26 is seated on the valve seat 32 by the seal member 34, the airtightness is maintained. The structure of the seal member 34 will be described later.
[0025]
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 attached to the base plate 38, and the inside of the casing 40. And a cylinder mechanism (drive source) 42 disposed in the cylinder.
[0026]
As shown in FIG. 2, the base plate 38 is formed with a pair of through holes 44a and 44b having a substantially circular cross section for inserting the pair of valve rods 24a and 24b, and a lower surface portion thereof. A recess 48 (see FIG. 1) having a semicircular cross section for supporting a support roller (support member) 46 described later is formed. The diameters of the through holes 44a and 44b are slightly larger than the diameters of the valve rods 24a and 24b, and the through holes 44a and 44b have one end portion of the bellows 50 covering a predetermined portion of the valve rods 24a and 24b. The ring body 52 that holds is fitted.
[0027]
As shown in FIG. 3, a packing (seal member) 51 surrounding the outer peripheral surfaces of the valve rods 24 a and 24 b is sandwiched between the bellows 50 and the valve box 30, and the packing 51 includes a piston 60. When reaching the top dead center or bottom dead center which is the displacement end position, the valve rods 24a and 24b come into contact with the upper annular step 27a or the lower annular step 27b 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.
[0028]
Further, as shown in FIG. 12, a first buffer member 53 formed of a resin material such as urethane resin or polyurethane resin is mounted in the hole portion on the base plate 38, and the first buffer member 53 is mounted. Is fixed in the hole through a metal fitting 55 and a retaining ring 57. The first buffer member 53 functions to absorb the impact of the support roller 46 by contacting the support roller 46 when the support roller 46 is engaged with the recess 48.
[0029]
As shown in FIG. 3, the cylinder mechanism 42 has convex portions 54 (see FIG. 2) projecting outward on both side surfaces, and one end portion of the cylinder plate 42 is formed on the base plate 38 via a screw member (not shown). A cylinder tube 56 to be fixed, a piston 60 accommodated so as to be displaceable along a cylinder chamber 58 in the cylinder tube 56, and one end portion are connected to the piston 60 and extend to the outer peripheral surface along the axial direction. A piston rod 64 having a spline groove 62 formed thereon; and a spline bearing member 68 provided with a plurality of balls 66 fixed to the cylinder tube 56 and engaged with the spline grooves 62 of the piston rod 64.
[0030]
A piston packing 70 that holds the upper cylinder chamber 58 a and the lower cylinder chamber 58 b divided by the piston 60 in an airtight manner is attached to the outer peripheral surface of the piston 60, and is close to the piston packing 70. A second buffer member 72 that is in contact with the upper end portion of the spline bearing member 68 and absorbs the impact when the piston 60 reaches bottom dead center is mounted on the bottom surface portion. For example, the second buffer member 72 is preferably formed of a resin material such as urethane resin or polyurethane resin.
[0031]
The upper cylinder chamber 58a and the lower cylinder chamber 58b are supplied with a pressure fluid (for example, compressed air) via a tube (not shown) connected to a pressure fluid supply source (not shown). Under the switching action of the switching valve, the pressure fluid is supplied to either the upper cylinder chamber 58a or the lower cylinder chamber 58b.
[0032]
Further, as shown in FIGS. 2 and 3, the drive unit 22 includes a lever member (first displacement member) 78 fixed to the other end of the piston rod 64 via a lock nut 74 and a spacer 76, and It has a displacement member (second displacement member) 80 that is displaced integrally with the lever member 78.
[0033]
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, and the projecting pieces 82a and 82b have springs to be described later. A substantially circular recess 86 to which one end of the member 84 is engaged is formed. On both side surfaces of the lever member 78, elongated holes 88a and 88b cut out in a substantially oval shape are formed, respectively, and the elongated holes 88a and 88b are rollers fixed to the displacement member 80 via pin members 90, respectively. 92 is provided to engage.
[0034]
Further, a pair of pin members 94 are fitted to the upper sides of both side surfaces of the lever member 78 through holes, and one end portions of the pin members 94 are formed on both side surfaces of the displacement member 80. It is provided so as to engage with the joint groove 96.
[0035]
As shown in FIGS. 2 and 3, a pair of flange portions 98 a and 98 b projecting by a predetermined length in the lateral direction are formed on both side surfaces of the displacement member 80 that extend substantially in parallel. The flange portions 98a and 98b are formed with a hole portion 100 having a substantially circular cross-section into which the other end portions of the valve rods 24a and 24b are inserted, and are locked to the screw portions of the valve rods 24a and 24b. The valve rods 24 a and 24 b are fixed to the displacement member 80 via the.
[0036]
A spring member 84 is interposed between the set of flange portions 98a and 98b of the displacement member 80 and the set of protruding pieces 82a and 82b of the lever member 78, respectively. The other end of the spring member 84 is engaged with the circular recess 86 of the protruding pieces 82a and 82b. The valve rods 24a and 24b are fixed to the flanges 98a and 98b. .
[0037]
A bellows 50 is provided at the other end of the valve rods 24a and 24b so as to cover the outer peripheral surface thereof, and one end of the bellows 50 can be freely rotated by a ring body 52 held by a base plate 38. The other end is fixed to a ring body 104 fitted on the valve rods 24a and 24b.
[0038]
Further, on both side surfaces of the displacement member 80, engaging groove portions 96 are formed, which are engaged with one end portions of the pin member 94 locked to the lever member 78, respectively. When the pin member 94 is engaged with the lower end portion 96a of the engaging groove portion 96, the lever member 78 and the displacement member 80 are displaced in the vertical direction and the front-rear direction (direction substantially orthogonal to the paper surface in FIG. 3). It is positioned in a state where it is prevented and spaced apart by a predetermined distance along the vertical direction, and moves up and down integrally in this state. Then, the pin member 94 is detached from the lower end portion 96a of the engaging groove portion 96 and ascends along the inclined portion 96b (see FIG. 2), whereby the valve disk 26 can be tilted.
[0039]
Further, a pair of support rollers 46 are pivotally supported on the upper part of the bifurcated displacement member 80, and the support roller 46 is a concave portion 48 in which the base plate 38 is curved at the displacement end position of the displacement member 80. The valve disc 26, the valve rods 24a and 24b, and the displacement member 80 are tilted by a predetermined angle θ (see FIG. 11) with the support roller 46 that is inserted into the recess 48 and engaged with the recess 48 as a fulcrum.
[0040]
Furthermore, a long hole 106 having an elliptical cross section through which the piston rod 64 is inserted is formed in the lower part of the displacement member 80, and when the displacement member 80 tilts, the piston rod 64 extends along the long hole 106. It is provided so as to be displaced (see FIG. 5).
[0041]
Here, the seal member 34 will be described in detail. The seal member 34 has a base portion 200 and a bulging portion 206 integrally formed from rubber, preferably synthetic rubber, for example, silicon rubber, and the base portion 200 is firmly held in the annular groove 33. As can be understood from FIG. 8, the bulging portion 206 bulges from the base portion 200 in an arc shape toward the valve seat 32 and is curved with the base portion 200. A second recess 204. A first arc portion 218 extending from the deepest portion 214 to the vertex 208 is formed to form the first concave portion 202, and the vertex from the deepest portion 216 to form the second concave portion 204. A second arc portion 220 reaching 208 is formed. A central imaginary line 212 perpendicular to the bottom surface 210 of the annular groove 33 is drawn from the apex 208 of the bulging portion 206. When a line a perpendicular to the end surface of the first arc portion 218 is drawn between the vertex 208 and the deepest portion 214 of the first recess 202 with respect to the central imaginary line 212, the vertical line a is drawn. The straight line a extends in the opposite direction from the central virtual line 212 and is longer than the vertical line b reaching the end surface of the second arc portion 220. In other words, the first arc portion 218 side is set so that its mass is larger than that of the second arc portion 220 side with the central virtual line 212 as the center. Further, a straight line c between the deepest portion 214 of the first recess 202 and the bottom surface 210 that is parallel to the central imaginary line 212 is the deepest of the second recess 204 that is parallel to the central imaginary line 212. It is set to be larger than a straight line d between the portion 216 and the bottom surface 210.
[0042]
In this case, the first circular arc portion 218 includes a first straight line portion 218a, and the first virtual line 222 extending from the first straight line portion 218a to the central virtual line 212 and the central virtual line The angle formed between the second circular arc part 220 and the second virtual arc part 220 includes the second straight line part 220a, and the second straight line part 220a extends to reach the central imaginary line 212. If the angle formed between the second virtual line 224 and the central virtual line 212 is θ2, the angle θ1 may be set to be larger than the angle θ2. Further, if the angle θ2 is set to be smaller than or equal to 10 °, it is preferable because of excellent blocking performance.
[0043]
In the embodiment of the present invention, the seal member 34 is fitted so that the second recess 204 is inside the annular groove 33 (see FIGS. 8 and 9). On the contrary, as shown by a broken line, it is a matter of course that a predetermined sealing effect can be obtained even when the second recess 204 is fitted so as to be outside the annular groove 33.
[0044]
The operation and effect of the shut-off valve configured as described above will be described. In the following description, the piston 60 is located at the lowermost position (bottom dead center) of the cylinder chamber 58, and the opening state in which the passage 28 formed in the valve box 30 is not blocked by the valve disk 26 is described as the initial position. To do.
[0045]
In this case, since the lever member 78 is pressed downward by the elastic force of the spring member 84 at the initial position, the pin member 94 fixed to the lever member 78 is engaged with the engaging groove portion 96 of the displacement member 80. It is in the state hold | maintained at the lower end part 96a. In the initial position, the roller 92 is engaged with the upper portions of the long holes 88 a and 88 b formed on both side surfaces of the lever member 78.
[0046]
In the initial position, a pressure fluid is supplied from a pressure fluid supply source (not shown) to a lower cylinder chamber 58b through a tube (not shown). The piston 60 rises under the action of the pressure fluid supplied to the lower cylinder chamber 58b, and the piston rod 64 connected to the piston 60 also rises. In this case, the upper cylinder chamber 58a is assumed to be open to the atmosphere under the action of a switching valve (not shown).
[0047]
As the piston rod 64 rises, the lever member 78, the displacement member 80, the valve rods 24a and 24b, and the valve disk 26 rise together with the piston rod 64. In this case, the lever member 78 is pressed downward by the elastic force of the spring member 84, and a pair of pin members 94 fixed to both side surfaces of the lever member 78 are engaging groove portions of the displacement member 80. The lever member 78 and the displacement member 80 are held at the lower end portions 96a of the plate 96 at predetermined positions that prevent the positional deviation in the up-down direction and the front-rear direction (direction substantially orthogonal to the paper surface in FIG. 3), respectively. Positioned and held. Therefore, the lever member 78 and the displacement member 80 are integrally raised while being positioned and held at the predetermined position.
[0048]
When the piston rod 64 moves up, a plurality of balls 66 roll and circulate along the spline grooves 62 formed in the piston rod 64, and the piston rod 64 is a spline bearing member fixed to the cylinder tube 56. 68 prevents rotation in the circumferential direction and prevents rotation.
[0049]
When the piston rod 64 is raised and one end of the displacement member 80 comes into contact with the base plate 38, the displacement member 80 reaches the displacement end position, and the valve disk 26 faces the opening of the passage 28 ( (See FIG. 7). At that time, the support roller 46 provided on the upper portion of the displacement member 80 engages with the curved concave portion 48 of the base plate 38 and abuts against the first buffer member 53 to absorb the impact.
[0050]
After the displacement member 80 reaches the displacement end position, the piston rod 64 further rises, so that the displacement member 80 is moved into the recess 48 under the engagement action of the rollers 92 with the long holes 88a and 88b of the lever member 78. The passage 28 is closed by tilting by a predetermined angle θ with the supporting roller 46 to be engaged as a fulcrum, and the valve disk 26 is seated on the valve seat 32 (see FIG. 12).
[0051]
That is, after the displacement member 80 reaches the displacement end position, only the lever member 78 rises by further raising the piston rod 64 against the elastic force of the spring member 84. At this time, the displacement member 80 Under the engaging action of the roller 92 with the long holes 88a and 88b formed on both side surfaces of the lever member 78, the support roller 46 is tilted by a predetermined angle θ (see FIG. 12). When the displacement member 80 tilts with the support roller 46 as a fulcrum, the pin member 94 fixed to both side surfaces of the lever member 78 is detached from the lower end portion 96a of the engaging groove portion 96 of the displacement member 80 and the inclined portion 96b. Ascend along.
[0052]
Therefore, the valve disk 26 fixed to the displacement member 80 via the valve rods 24a and 24b is moved from the state where the displacement member 80 is opposed to the passage 28 at a predetermined interval by tilting the displacement member 80 by the predetermined angle θ. Displaces approximately horizontally toward the side. As a result, the seal member 34 provided on the valve disk 26 is seated on the valve seat 32, and the passage 28 is airtightly closed.
[0053]
That is, as described above, when the valve disk 26 is tilted by a predetermined angle θ with the support roller 46 engaged with the recess 48 as a fulcrum, the seal member 34 provided on the valve disk 26 is The pressure is pressed by the valve seat 32 while the shape is deformed, and the passage 28 is airtightly closed. In other words, since the mass of the first arc portion 218 side is larger than that of the second arc portion 220 side, when the valve seat 32 is pressed, as shown in FIG. The valve seat 32 is bent and pressed. For this reason, the degree of adhesion to the valve seat 32 is further enhanced.
[0054]
Next, when the valve disk 26 is separated from the valve seat 32 and the passage 28 is opened, the piston 60 is lowered by supplying pressure fluid to the upper cylinder chamber 58a under the switching action of a switching valve (not shown). 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).
[0055]
That is, after the displacement member 80 is tilted by a predetermined angle θ toward the opposite direction under the engagement action of the roller 92 with the long holes 88a and 88b, the lever member 78 and the displacement member 80 are integrally formed with the piston rod 64. Is lowered to the initial position. At that time, the impact 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 is lowered, the lever member 78 is pressed downward by the elastic force of the spring member 84, so that the flow rate of the pressure fluid supplied to the upper cylinder chamber 58a can be suppressed. .
[0056]
As described above, in the present embodiment, the seal member 34 is pressed against the valve seat 32 while being deformed in shape. That is, the pressed and deformed shape bends toward the second arc portion 220 side as shown by the line in FIG. 9, and the pressure contact surface with the valve seat 32 rather than the first arc portion 218. Is seated (closely).
[0057]
Further, if the airtightly shielded passage 28 communicating with the second recess 204 side is maintained at a positive pressure, the positive pressure causes the second recess 204 side of the seal member 34 to move. The valve seat 32 can be crimped. Of course, a sufficient shielding effect can be obtained even when the pressure on the passage 28 side is negative and the periphery of the valve disk 26 is positive, or even when the passage 28 side and the periphery of the valve disk 26 are both negative pressure or positive pressure. .
[0058]
【The invention's effect】
According to the present invention, by improving the shape of the sealing member, it is possible to improve the sealing performance and increase the airtight holding ability, and to reduce the generation of dust and the like as much as possible. It is also possible to improve the sealing performance without pursuing the rigidity of the gate valve, and to manufacture the gate valve in a small size 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 along the axial direction of the gate valve.
4 is a cross-sectional view taken along the line IV-IV in FIG. 3;
5 is a cross-sectional view taken along line VV in FIG. 3. FIG.
6 is a cross-sectional view taken along the line VI-VI in FIG. 3;
7 is a longitudinal sectional view taken along line VII-VII in FIG.
8 is an enlarged view of a seal member fitted to the valve disk shown in FIG.
FIG. 9 is an enlarged view showing a shape in which the seal member shown in FIG. 7 is deformed by being pressed by the valve seat.
10 is a longitudinal sectional view showing a state where 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 the axis.
FIG. 13 is a longitudinal sectional view along the axial direction of a gate valve according to the prior art.
14 is a longitudinal sectional view of the gate valve shown in FIG. 13 along the axial direction.
15 is a perspective view of a cylinder tube constituting the gate valve shown in FIG.
[Explanation of symbols]
20 ... Gate valve 22 ... Drive unit
24a, 24b ... Valve rod 26 ... Valve disc
28 ... passage 30 ... valve box
32 ... Valve seat 34 ... Sealing member
38 ... Base plate 40 ... Casing
42 ... Cylinder mechanism 44a, 44b ... Through hole
46 ... support rollers 48, 86 ... concave
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 member 82a, 82b ... Projection piece
84 ... Spring members 88a, 88b, 106 ... Long holes
90, 94 ... Pin member 92 ... Roller
96 ... engaging groove 98a, 98b ... flange
200 ... base 202 ... first recess
204 ... second recess 206 ... bulging portion
208 ... Vertex 210 ... Bottom
212 ... Virtual center line 214 ... Deepest part of first recess
216: Deepest portion of second recess 218: First arc portion
218a ... 1st straight line part 220 ... 2nd circular arc part
220a ... second straight part 222 ... first imaginary line
224 ... second virtual line

Claims (5)

In the valve structure of the shut-off valve provided with a groove that circulates on one side surface of the valve disk facing the valve seat, and fitting a seal member into the groove,
The seal member includes a base and a bulging portion that is molded integrally with the base, and the bulging portion has a first concave portion and a second concave portion 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, and is formed from the deepest portion of the first concave portion to the apex of the bulging portion. Between the first arc portions, the vertical line a drawn with respect to the end surface of the first arc portion on the basis of a central virtual line orthogonal to the bottom surface of the groove from the apex is opposite to the line a The relationship with a vertical line b extending in the direction and drawn from the deepest part of the second recess to the end surface of the second arc part formed from the deepest part to the apex is a> b There is a valve structure of a shut-off valve characterized by being. In the valve structure of the shut-off valve provided with a groove that circulates on one side surface of the valve disk facing the valve seat, and fitting a seal member into the groove,
The seal member includes a base and a bulging portion that is molded integrally with the base, and the bulging portion has a first concave portion and a second concave portion on the base side,
When the sealing member is sealed, the bulging portion bends toward the second recess and is pressed against the valve seat, and the first arc portion includes a first straight portion, and the first straight line An angle formed between a first imaginary line extending from the center to the central imaginary line and the central imaginary line is θ1, and a second straight line portion is included in the second arc portion, and the second straight line When the angle formed between the second imaginary line extending from the center to the central imaginary line and the central imaginary line is θ2, the first arc portion and the second arc such that θ1> θ2. The valve structure of the shut-off valve characterized by forming the circular arc part of this . The valve structure according to claim 2 ,
The valve structure of the shut-off valve, wherein the angle θ2 is θ2 ≦ 10 °. The valve structure according to claim 1 , wherein
A distance c between the deepest portion of the first recess and the bottom surface parallel to the central imaginary line, and a distance d between the deepest portion of the second recess and the bottom surface parallel to the central imaginary line. The valve structure of the shut-off valve, wherein c ≧ d. In the valve structure according to any one of claims 1 to 4 ,
The valve structure of a shut-off valve, wherein the seal member is made of rubber.

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