JP2004052886A - Gate valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact gate valve with good air-tightness, low manufacturing cost capable of moving a valve plate with small driving force and suppressing installation space narrowly. <P>SOLUTION: The gate valve 1 is equipped with a valve casing 2 having an opening 2f, a shaft 5 penetrating the valve casing 2 and rotatable around an axis line, the valve plate 3 which rotates along with the rotation of the shaft 5 and opens/closes the opening 2f, and seal members 8, 9 sealing the penetrating part of the valve casing 2 of the shaft 5. Since the part of the shaft penetrating the valve casing 2 is sealed, and the shaft 5 is rotated in the sealing part, there is little abrasion of the sealing part produced by grain powder bodies flowing in the flow path, and air-tightness can be kept good. It is suitable that the valve plate 3 moves in the axial direction of the shaft along with the rotation of the shaft 5, an urging means 13 is provided to urge the valve plate 3 to the opening 2f side of the valve casing 2, and positioning means 10, 12 are provided to adjust the axial position of the shaft 5 with respect to the valve casing 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gate valve, and more particularly to a gate valve used to open and close a flow path in the field of supply and transportation of any fluid such as gas, liquid, and powder.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, when a fluid such as a granular material is supplied and transported, a flow path is opened and closed by, for example, a gate valve as shown in FIG.
[0003]
The gate valve 21 is a so-called valve plate seal type gate valve that opens and closes an opening 22 a by a valve plate 23 that reciprocates inside a valve box 22 to open and close a flow path. The valve plate 23 reciprocates inside the valve box 22 by an air cylinder 28 on a shaft 26 connected to the valve plate 23 by a knuckle joint 29. In order to seal the periphery of the valve plate 23, a gland packing 24 and a packing suppressor 25 are provided. Below the valve plate 23, a valve plate holding rod 30 for holding the valve plate 23 is provided.
[0004]
However, in this gate valve 21, the sealing is performed only by the low airtight gland packing 24, and the gland packing 24 has to be bent with a small radius at both corners of the valve plate 23. The gap between the valve 23 and the valve box 22 cannot be completely closed, and it is difficult to maintain airtightness.
[0005]
Therefore, for example, in the conventional gate valve 41 shown in FIG. 3, the valve plate 43 which reciprocates inside the valve box 42 by operating the handle 47 is connected to the shaft 46, and the shaft 46 is connected to the gland packing 44 and the packing holder 45. Sealed by.
[0006]
[Problems to be solved by the invention]
As described above, the conventional gate valve 21 shown in FIG. 2 has a problem in airtightness, and the powder in the flow path enters the gland packing 24 to increase the sliding resistance. A large driving force is required for the reciprocating movement. Furthermore, since the valve plate 23 itself penetrates the gland packing 24, the valve plate 23 is supported by the gland packing 24 and its position is fixed, and the valve plate 23 and the valve box 22 are brought into close contact with each other to open the opening 22a. It becomes difficult to close. In addition, since the valve plate 23 reciprocates, the overall length of the device becomes longer, and it is necessary to increase the installation space for the gate valve. In addition to these, there is a problem that the manufacturing cost of the entire valve is high.
[0007]
Further, although the conventional gate valve 41 shown in FIG. 3 can improve the airtightness, the overall length of the apparatus is longer than that of the gate valve 21 shown in FIG. There was a problem that it was necessary to increase it. In addition, since the amount of the powder particles accumulated in the valve box portion 42a through which the shaft 46 penetrates increases, periodic cleaning is required, and much labor is required for maintenance. There is also a problem that the manufacturing cost of the entire valve is high.
[0008]
In view of the above, the present invention has been made in view of the above-described problems of the conventional gate valve, and has good airtightness, can move a valve plate with a small driving force, is compact, and suppresses a small installation space. And to provide a gate valve with low manufacturing cost.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 is a gate valve, comprising: a valve box having an opening; a shaft that penetrates the valve box and is rotatable around an axis; It is characterized by comprising a valve plate that rotates with movement and opens and closes the opening, and a seal member that seals a penetrating portion of the valve box of the shaft.
[0010]
According to the first aspect of the present invention, a portion of the shaft penetrating the valve box is sealed, and the shaft rotates at the sealed portion instead of sliding in the axial direction, so that the powder flowing through the flow path is sealed. Abrasion of the seal portion caused by the particles is small, and good airtightness can be maintained. In addition, the increase in frictional resistance at the seal portion of the shaft is remarkably reduced, the driving force for rotating the valve plate can be reduced, and the entire device can be made compact and the installation space can be reduced.
[0011]
According to a second aspect of the present invention, in the gate valve according to the first or second aspect, the valve plate moves in an axial direction of the shaft with rotation of the shaft.
[0012]
According to the second aspect of the present invention, the valve plate moves in the axial direction of the shaft along with the rotation of the shaft, so that the valve plate is moved in the direction to close the opening of the valve box while rotating the valve plate. Thus, the valve plate and the valve box can be closed without a gap, and the airtightness can be further improved.
[0013]
A third aspect of the present invention is the gate valve according to the first, second or third aspect, further comprising an urging means for urging the valve plate toward the opening of the valve box.
[0014]
According to the third aspect of the present invention, the valve plate is urged toward the opening by the urging means, whereby the valve plate is pressed against the valve box. It can be reliably prevented.
[0015]
According to a fourth aspect of the present invention, in the gate valve according to the third aspect, a positioning means for adjusting a position of the shaft with respect to the valve box in an axial direction is provided.
[0016]
According to the fourth aspect of the present invention, by adjusting the axial position of the shaft with respect to the valve box by the positioning means, it is possible to adjust the pressing force of the urging means on the valve plate against the opening of the valve box. Thus, it is possible to more reliably prevent a leak or the like.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a specific example of an embodiment of a gate valve according to the present invention will be described with reference to the drawings.
[0018]
FIG. 1 shows an embodiment of a gate valve according to the present invention. This gate valve 1 is roughly divided into a valve box 2, a shaft 5 that penetrates through the valve box 2 and can rotate around an axis, and a shaft 5. 5 includes an arm 4 that rotates with the rotation of the valve 5 and the valve plate 3 that rotates with the arm 4.
[0019]
The valve box 2 includes an upper flange 2a surrounding the opening 2f, a lower flange 2b, a top plate 2c, a bottom plate 2d, and a side plate 2e. The valve plate 3, the arm 4, and the like are housed therein. . In this embodiment, the valve box 2 is integrally formed by a welding structure, but may be divided into a plurality of parts and fastened by bolts or the like.
[0020]
The valve plate 3 is formed in a disk shape, and is connected to the arm 4 via a shaft 3a. A compression spring 13 is interposed in the shaft portion 3a, and urges the valve plate 3 toward the upper flange 2a (opening 2f) of the valve box 2.
[0021]
The arm 4 is connected to the valve plate 3 and fixed to the shaft 5 as described above. The shaft 3a of the valve plate 3 is inserted into the recess 4a at the tip of the arm 4, and pivotally supports the shaft 3a via the compression spring 13.
[0022]
The shaft 5 is rotatably supported by the valve box 2, and is provided with rod seals 8 and 9 in the upper housing 6 and the lower housing 7 to seal a penetrating portion of the valve box 2. Note that a gland packing can be used in place of the rod seals 8 and 9 as in the case of the conventional example.
[0023]
A male screw portion 5a is screwed into the lower end of the shaft 5, and is screwed with a female screw portion 10a screwed inside the adjustment bush 10. On the outside of the adjustment bush 10, a male screw portion 10b is screwed, and is screwed with the nut 12. In addition, the pitch of the male screw part 5a and the male screw part 10b are formed to be different from each other. The nut 12 is fixed to the lower housing 7.
[0024]
A handle 11 is fixed to the upper part of the shaft 5, and by rotating the handle 11, the valve plate 3 can be rotated in the direction of arrow A in FIG. 1A via the shaft 5 and the arm 4. . Note that an air actuator or the like may be used instead of the handle 11.
[0025]
Next, the operation of the gate valve 1 having the above configuration will be described.
[0026]
When the handle 11 is turned in the direction in which the valve is closed (the direction of arrow B) in the open state of the gate valve 1, the shaft 5 is turned. By the rotation of the shaft 5, the male screw portion 5a of the shaft 5 and the female screw portion 10a of the adjustment bush 10 are screwed, and the shaft 5 rotates while rising. As a result, the arm 4 rises while rotating, and the valve plate 3 approaches the upper flange 2a while rotating.
[0027]
Then, the valve plate 3 comes into contact with the upper flange 2a, and the valve spring 3 is pressed against the upper flange 2a by the bending of the compression spring 13. As a result, the opening of the upper flange 2a is completely closed by the valve plate 3. The pressing force of the compression spring 13 can be adjusted by rotating the adjustment bush 10. After the position of the adjustment bush 10 is adjusted, the adjustment bush 10 can be fixed to the lower housing 7 with a nut 12 and a set screw (not shown).
[0028]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a gate valve that has good airtightness, can move a valve plate with a small driving force, can be compact, can reduce an installation space, and has a low manufacturing cost. be able to.
[Brief description of the drawings]
FIG. 1 is a view showing an embodiment of a gate valve according to the present invention, wherein (a) is a partially cutaway plan view and (b) is a sectional view.
FIG. 2 is a view showing an example of a conventional gate valve, wherein (a) is a plan view and (b) is a cross-sectional view.
FIG. 3 is a cross-sectional view showing another example of a conventional gate valve.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gate valve 2 Valve box 2a Upper flange 2b Lower flange 2c Top plate 2d Bottom plate 2e Side plate 2f Opening 3 Valve plate 3a Shaft part 4 Arm 4a Depression 5 Shaft 5a Male thread part 6 Upper housing 7 Lower housing 8 Rod seal 9 Rod seal 10 Adjusting bush 10a Female thread 10b Male thread 11 Handle 12 Nut 13 Compression spring

Claims (4)

A valve box having an opening;
A shaft that penetrates the valve box and is rotatable around an axis;
A valve plate that rotates with the rotation of the shaft and opens and closes the opening;
A sealing member for sealing a penetrating portion of the valve box of the shaft. The gate valve according to claim 1, wherein the valve plate moves in the axial direction of the shaft as the shaft rotates. 3. The gate valve according to claim 1, further comprising a biasing unit configured to bias the valve plate toward an opening of the valve box. 4. The gate valve according to claim 3, further comprising a positioning unit that adjusts an axial position of the shaft with respect to the valve box.

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