JP2741811B2 - Soft seal gate valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft seal gate valve and, more particularly, to a bob roita type soft seal gate valve used for water supply and sewerage, for example.

[0002]

2. Description of the Related Art A conventional soft seal gate valve 1 of this kind shown in FIG. 4 includes a valve box 2 and a valve body 3 inside the valve box 2.
Is accommodated. A lid 4 is attached to the upper part of the valve box 2,
Thereby, a space 5 is formed above the valve body 3. This space 5 communicates with the bottom surface of the valve element 3 through a hole 6 provided at the center of the valve element 3.

In the closing operation, when the valve body 3 is pushed down, the flow velocity passing through the portion A increases, and a pressure difference occurs between the portion A and the portion B. For this reason, the fluid in the portion B is drawn into the space 5 as shown by an arrow 8, for example. As a result, the pressure in the space 5 increases, and this pressure acts as a force for pushing down the valve body 3.

[0004]

In the above-mentioned prior art,
At the time of closing, the pressure in the space 5 acts as a force for pushing down the valve body 3, so that it can be easily closed. However, since the pressure in the space 5 is still applied to the valve body 3 after closing, a considerably large force is required at the time of opening, and there is a problem that opening is difficult.

It is, therefore, a primary object of the present invention to provide a soft seal gate valve that can be easily opened.

[0006]

SUMMARY OF THE INVENTION The present invention, viewed contains a lid attached to the valve body and valve box top for accommodating the valve body, the valve body
A first space is formed above the valve body in a state where the valve is closed.
A soft seal gate valve that communicates with a first space between a valve box and a valve body bottom when the valve body is closed.
A second space is formed, and the pressure in the second space is applied to the bottom of the valve body.
A soft seal gate valve characterized by acting in a direction .

[0007]

With the valve body closed, the pressure of the fluid filled in the second space acts in a direction to push up the valve body.

[0008]

According to the present invention, when the valve is closed, a force in a direction of pushing up the valve can be applied to the valve, so that the force required in the initial stage of the valve opening operation can be reduced.
Can be reduced. The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a soft seal gate valve 10 of this embodiment includes a valve box 12. The valve box 12 includes a first portion 12a that becomes a part of a conduit and a second portion 12b that is formed continuously above the first portion 12a. First part 1
On the upstream side of 2a, an upstream-side receiving pipe 16 to which the seal ring 14 is attached is formed near the end thereof, and on the downstream side,
A downstream receiving pipe 18 to which the seal ring 14 is attached is formed near the end.

A valve body 20 is accommodated in the valve box 12. On the side surface of the valve body 20, substantially "U" -shaped valve seats 22 and 24 made of, for example, SBR (styrene butadiene rubber) for sealing a gap between the valve body 20 and the first portion 12a have holes 34 described later. Are formed so as to sandwich them. Further, a ring-shaped sealing member 26 made of, for example, SBR for sealing a gap between the valve body 20 and the second portion 12b.
Are formed continuously with the upper ends of the valve seats 22 and 24.
A cavity 30 communicating with the first space 28 above the valve body 20 is formed inside the valve body 20, and a space below the valve body 20 (the internal space of the first portion 12 a) is formed at the bottom of the valve body 20. A hole 34 communicating between the cavity 32 and the cavity 30 is formed. A valve stem 36 is attached to the upper part of the valve body 20.

A lid 38 is attached to the upper part of the valve box 12 by bolts and nuts 40, and a packing box 42 is attached to the upper part of the lid 38 by bolts 44. Valve stem 3
The upper end of 6 is projected upward through the packing box 42, and a cap 46 is put on the upper end. A packing 48 is attached to a portion of the packing box 42 that receives the valve stem 36 in a line in the axial direction. When used, the receiving tube 16
Pipes 50 and 52 are inserted into the pipes 18 and 18, and a fluid such as water flows through a pipe containing the pipes.

In the closing operation, when the valve body 20 is pushed down by rotating the cap 46, the valve body 20
, The flow velocity passing through the lower space 32 gradually increases, and a pressure difference occurs between the portion A and the portion B. Therefore, the valve element 2
The fluid in the portion B is drawn into the first space 28 through the gap formed between the zero and the second portion 12b, and the pressure in the first space 28 increases. When the valve body 20 is further pushed down, the sealing member 26 and the inner projection 54 of the second portion 12b
And the first space 28 is sealed. At the same time, the valve seats 22 and 24 and the inner surface of the first portion 12a are in close contact with each other, and between the valve body 20 and the first portion 12a, as can be clearly understood from FIG. A second space 56 defined by the above is formed. Since the second space 56 communicates with the first space 28 via the hole 34 and the cavity 30, the fluid in the second space 56 has the same pressure as the pressure applied to the fluid in the first space 28. As a result, the valve body 20
An upward force F (direction in which the valve body 20 is lifted) as shown by an arrow in FIG. 2 acts.

According to this embodiment, in a state of complete closing valve 20, it is possible to exert a force F to attempt to lift it to the valve body 20, first valve opening operating
The required force at the initial stage can be reduced and the valve can be opened easily. FIG.
The soft seal gate valve 58 of another embodiment shown in FIG. 1 includes a substantially shell-shaped valve element 62 having a valve seat 60 made of, for example, SBR on the outer surface thereof.
A concave portion 64 having an opening area larger than the opening area of No. 4 is formed. When the valve body 62 is completely closed (the state shown in FIG. 3), the second portion is formed by the recess 64 and the inner surface of the first portion 12a.
A space 66 is defined. Therefore, in this embodiment, similarly to the previous embodiment, a force F for lifting the valve body 62 can be applied to the valve body 62 by the pressure of the fluid filled in the second space 66.

The valve box 12, the valve bodies 20 and 62, the lid 38, the packing box 42 and the like in each of the above embodiments may be formed of a synthetic resin such as impact-resistant hard vinyl chloride, or It may be formed of a metal such as cast iron.

[Brief description of the drawings]

FIG. 1 is an illustrative view showing one embodiment of the present invention;

FIG. 2 is an illustrative view showing a closed state of the embodiment of FIG. 1;

FIG. 3 is an illustrative view showing another embodiment of the present invention;

FIG. 4 is an illustrative view showing a conventional technique;

[Explanation of symbols]

 10, 58 ... soft seal gate valve 12 ... valve box 20, 62 ... valve body 22, 24, 60 ... valve seat 28 ... first space 30 ... cavity 34 ... hole 56, 66 ... second space

Claims (1)

(57) [Claims] 1. A valve body seen including a lid attached to the valve box and the front Kiben box top for housing the state odor of closing the valve body
A first space formed above the valve body, wherein a soft seal gate valve communicates with the first space between the valve box and the valve body bottom in a state where the valve body is closed . Form two spaces
The pressure in the second space is applied upward to the bottom of the valve body.
A soft seal gate valve characterized by being used.