JPS6222702Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The invention provides a valve stem with a male thread on the inner end.
The valve body is supported so that it can only rotate freely while penetrating the hole-forming wall of the valve body, and the entire surface of the valve body is covered with rubber. The valve body is provided with a hole-forming portion that is located closer to the hole-forming wall than the female thread member and surrounds the valve stem, and the hole-forming portion is arranged so that the hole-forming portion surrounds the valve stem when the valve body moves to the valve open position as the valve stem rotates. The present invention relates to a gate valve configured such that the hole forming portion can be brought into pressure contact with a forming wall.

[Conventional technology]

Such gate valves are subject to inspection such as O-ring replacement on the valve stem bearing located outside the hole forming wall of the valve box.
Although maintenance work can be performed with the valve in the open state, when used with high-pressure fluid, there is a risk of fluid leaking to the valve stem bearing side. In other words, in the gate valve of the conventional configuration, as shown in FIG. 5, in the valve open state,
The inner peripheral surface of the hole forming portion 31A of the valve body 31 and the valve stem 32
Since there is a gap between the hole forming portion 31A and the hole forming wall 33A of the valve body 33, leakage of fluid from the outside of the valve body 31 is prevented. First, fluid from inside the valve body 31 flows out to the bearing portion 34 side through the gap. More specifically, the valve body 31 generally has a hole for assembling the female screw member 35 and a hole for discharging the fluid that has entered the valve body 31. The fluid that has flowed into the gap flows out through the gap as described above.

[Problem for invention]

An object of the present invention is to reliably suppress leakage of fluid toward the bearing when the valve is open, by a simple modification that makes effective use of the original structure.

[Means to solve the problem]

The characteristic configuration of the present invention is that the outer surface of the valve stem located within the valve box and close to the hole forming wall of the valve box is formed into a cylindrical shape, and the outer surface of the valve stem located close to the hole forming wall of the valve body is formed on the inner circumferential surface of the hole forming portion of the valve body. The present invention is characterized in that the elastic material covering the valve body is provided with an elastic annular protrusion that presses against the cylindrical valve stem portion.

[Action/Effect]

Next, the effects of the feature configuration of the present invention will be described.

In other words, since the annular protrusion is brought into pressure contact with the columnar valve stem when the valve is open, fluid from inside the valve body can be prevented from flowing out to the bearing section located outside the hole forming wall. This is coupled with the action of preventing fluid from the entire outside of the valve body from flowing out to the bearing side through between the valve body and the hole forming wall when the valve is open. As a whole, it has become possible to reliably prevent fluid from leaking to the bearing side.

According to the present invention, focusing on the elastic material that covers the entire body for sealing, a simple modification can be made by simply providing the elastic material with the annular protrusion and forming the columnar valve stem portion on the valve stem. The desired purpose can be achieved with this method, which has great advantages in terms of implementation and production.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

As shown in FIGS. 1 and 2, a valve body 3 whose entire surface is covered with rubber 2 is placed in a valve box 1 equipped with a flange for connecting a fluid transport pipe in a downward closed position and an upward open position. The valve body 1 is provided with a seat surface 4 that is slidable in the valve body 1, and a seat surface 4 that is in pressure contact with the lower part of the valve body 3 in the closed position, and a seat surface 5 that is in pressure contact with the stepped portion formed at the upper and lower intermediate portions of the valve body 3. and a valve stem 6 having a male threaded portion 6A on the inner end side,
While penetrating the upper hole forming wall 1A of the valve box 1,
A bearing part 7 that supports the valve stem 1 only in a rotatable manner is provided on the upper part of the hole forming wall 1A,
In addition, a female threaded member 8 that is screwed into the male threaded portion 6A of the valve stem is installed in a non-rotating state, and the male threaded portion 6A of the valve stem is
A rotary operating portion 9 is attached to the upper end of the valve body 1, thereby forming a gate valve that opens and closes the flow path within the valve box 1 as the valve stem 6 rotates.

As shown in FIG. 3, the valve body 3 is provided with a hole forming portion 3A that surrounds the valve stem 6 and is located closer to the valve box hole forming wall 1A than the female screw member 8.
The outer surface of the valve stem portion 6B located within the valve box 1 and close to the hole forming wall 1A is configured such that the hole forming portion 3A can be brought into pressure contact with the hole forming wall 1A by moving to the valve opening position. is formed into a cylindrical shape, and the elastic member 2 is provided with an annular protruding portion 10 located on the inner peripheral surface of the hole forming portion 3A and in pressure contact with the cylindrical valve stem portion 6B. In this state, by bringing the hole forming portion 3A into pressure contact with the hole forming wall 1A, fluid from outside the valve body is directed to the bearing portion 7.
By preventing the fluid from flowing to the side and by pressing the annular protrusion 10 against the columnar valve stem portion 6B, the fluid that has entered the space of the valve body from outside the valve body through, for example, a water drain hole can be prevented from flowing to the bearing part. By working together with the action of preventing fluid from leaking to the bearing portion 7 side, leakage of the fluid toward the bearing portion 7 side as a whole can be reliably suppressed.

In short, the bearing bush 11 in the bearing portion 7
Inspection and maintenance work on the bearing section 7, such as replacing the O-ring 12 interposed between the valve stem 6 and the valve stem 6, can be carried out in an open state.

Next, another example will be described.

In FIG. 4, the annular protruding portion 10A is formed into an inclined tongue shape so that the columnar valve stem portion 6B is pushed aside by fluid pressure. In this case, although the annular protruding portion 10A can be reliably pressed against the columnar valve stem portion 6B using fluid pressure, when the valve stem 6 is used in a state where no large fluid pressure is applied, the rotational operating force of the valve stem 6 is This makes it possible to reduce the

Note that although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a partially cutaway front view of the gate valve, FIG. 2 is a sectional view taken along the - line in FIG. FIG. 4 is a cutaway side view showing a modified example of the annular protrusion, and FIG. 5 is a cutout side view of a conventional example. DESCRIPTION OF SYMBOLS 1... Valve box, 1A... Hole forming wall, 2... Elastic material, 3... Valve body, 3A... Hole forming part, 6... Valve stem, 6A... Male thread part, 6B... Pillar valve stem part,
8... Female thread part, 10, 10A... Annular protrusion part.

Claims (1)

[Scope of utility model registration request] A valve stem 6 having a male threaded portion 6A on the inner end side is supported rotatably only while penetrating the hole forming wall 1A of the valve body 1, and is attached to a valve body 3 whose entire surface is covered with an elastic material 2. , a female screw member 8 that is screwed into the male screw portion 6A is installed in a non-rotating state, and the hole forming portion 3A that surrounds the valve stem 6 is positioned closer to the hole forming wall 1A than the female screw member 8 and is attached to the valve body. 3, the gate valve is configured such that the hole forming portion 3A can be brought into pressure contact with the hole forming wall 1A by moving the valve body 6 to the valve open position as the valve stem 6 rotates, The outer surface of the valve stem portion 6B located within the valve box 1 and close to the hole forming wall 1A is formed into a cylindrical shape, and the cylindrical valve stem is located on the inner peripheral surface of the hole forming portion 3A. The elastic annular protrusion (10 or 10A) that presses against the portion 6B is attached to the elastic member 2.
A gate valve characterized by being prepared for.