JPH07151246A - Gate valve - Google Patents

Abstract

PURPOSE:To provide a gate valve which can surely prevent the trouble due to the application of an excessive torque. CONSTITUTION:A gate valve 10 is equipped with a valve casing 11 having a fluid flow passage 15A and a valve chamber 15B extending in the vertical direction to the axis of the fluid flow passages 15A, yoke 17 which is on the valve casing 11 and supports a valve rod 12, valve rod 12 which has a male screw and rises and lowers, and a valve element 13 which is installed on the valve rod 12 and opens and closes the fluid passage 15A through the rise and lowering in the valve chamber 15B, and an over-tightening preventing ring 30 is installed at the part inside the yoke 17 of the valve rod 12. At the lower part valve rod penetration part on the yoke 17, a collision surface 162 with which the over-tightening preventing ring 30 collides when the valve is perfectly closed is formed, and at the upper part valve rod penetration part in the yoke 17, a collision surface 172 with which the over-tightening preventing ring 30 collides when the valve is perfectly opened is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate valve suitable for use in pipelines for agricultural and marine equipment, water treatment equipment, construction equipment, plant equipment, water supply and the like.

[0002]

2. Description of the Related Art When a sluice valve is fully closed, a valve body collides with a valve seat provided in a valve box to close the valve, but the handle of a valve rod is operated with an excessive torque. In this case, since the valve stem presses the valve body strongly against the valve seat, excessive load may damage the valve body or the valve seat or cause excessive stress on the valve box, which may cause cracking. . In particular, recently, as a gate valve that is lightweight and has excellent corrosion resistance, a valve box and a valve body made of a synthetic resin material are widely used, but such a gate valve is compared to a valve made of a metal material. If the mechanical strength is low and an excessive closing operation is performed, the valve box or the valve body may be damaged by the force generated at the contact portion between the valve box and the valve body.

Therefore, in order to prevent such an accident due to overtightening of the valve, Japanese Utility Model Laid-Open No. 5-45367 discloses an overtightening prevention structure for a sluice valve. In this overtightening prevention structure, a stopper is provided at a valve shut-off position of a valve rod that is screw-fitted with a handle to limit relative screw-fitting of the valve rod with the handle.

[0004]

However, in the overtightening prevention structure described in Japanese Utility Model Laid-Open No. 5-45367, the valve rod is lengthened by at least the thickness of the stopper, which increases the cost and the gate valve. There is a problem in that the total height becomes high and bulky, which makes installation difficult. Further, although the above-mentioned overtightening prevention function has the function of preventing overtightening when the valve is fully closed, it does not have the function of preventing overtightening when the valve is fully opened, so an excessive load is applied even when the valve is fully opened, and The joint between the body and the valve rod, the yoke, or the like may be damaged.

The present invention relates to the above conventional sluice valve,
This was done in view of these problems.By reducing the length of the valve stem, cost reduction and ease of installation can be achieved, and in addition, when the valve is both fully closed and fully opened. An object of the present invention is to provide a sluice valve that exerts a tightening prevention function and can reliably prevent an accident caused by application of an excessive torque.

[0006]

To achieve the above object, a sluice valve according to the present invention comprises a valve box having a fluid passage and a valve chamber extending in a direction perpendicular to the axis of the fluid passage, and a valve. A yoke that is above the box and supports the valve rod, a valve rod that is equipped with a screw to move up and down, and a valve that is attached to the valve rod and that moves up and down in the valve chamber together with the valve rod to open and close the fluid flow path. In a sluice valve with a body, an overtightening prevention ring is attached to the inside of the yoke of the valve rod, and the abutment surface where the overtightening prevention ring abuts at the bottom valve rod penetrating portion in the yoke when the valve is fully closed. Is formed, and an abutting surface with which the overtightening prevention ring abuts when the valve is fully opened is formed in the upper valve rod penetrating portion in the yoke.

In the present invention, the means for raising and lowering the valve rod is not particularly limited. For example, a male thread is engraved on the valve rod, and a sleeve provided with a female thread to be screwed into the male thread is provided, and this sleeve is mounted on the yoke. The means for rotating the sleeve may be rotated by a drive handle, a gear mechanism, a cap and box spanner of an embedded valve, a power drive device using an electric motor, or the like. Means, etc. can be used.

[0008]

In the sluice valve of the present invention, the overtightening prevention ring is attached to the portion of the valve rod inside the yoke, and the overtightening prevention ring abuts the lower valve rod penetration portion inside the yoke when the valve is fully closed. The abutment surface is formed, and the abutment surface where the overtightening prevention ring abuts when the valve is fully opened is formed in the upper valve rod penetrating portion in the yoke. Inner surface (valve seat)
At the same time as the valve is abutted against the valve and fully closed, the overtightening prevention ring abuts against the abutment surface formed in the lower valve stem penetrating portion in the yoke, and the valve stem cannot be further lowered. As a result, the valve body, the valve rod, the connecting portion of the valve body and the valve rod, the valve box,
Excessive torque is prevented from being applied to the lid, the yoke, and the like.

Further, when the valve rod is lifted and the valve body is pulled up to the upper end of the fluid flow path (that is, fully opened), the overtightening prevention ring is formed in the upper valve rod penetrating portion in the yoke. You will not be able to raise the valve stem any more as it meets the face. Therefore, also in this case, excessive torque is prevented from being applied to the valve body, the valve rod, the connecting portion between the valve body and the valve rod, the valve box, the lid, the yoke, and the like.

Since the overtightening prevention ring is attached to the inside of the yoke of the valve rod and does not protrude above the yoke, the length of the valve rod should be shortened by at least the thickness of the overtightening prevention ring. You can

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 shows a fully closed state of an example of the sluice valve of the present invention, (A) is a side sectional view, (B) is a front sectional view, and FIG. 2 is the sluice valve of the present invention shown in FIG. Shows the state, (A)
Is a side sectional view, and (B) is a front sectional view.

As shown in FIGS. 1 and 2, the sluice valve 10
Is a valve box 11, a valve rod 12, a valve body 13, and a handle 14.
Have. The valve box 11 is configured by fastening the housing 15, the lid 16, and the yoke 17 together from below in this order with several fixing bolts 18. Also, the housing 15
Includes a fluid channel 15A and a valve chamber 15B extending in a direction perpendicular to the axis of the fluid channel 15A.

The valve rod 12 penetrates the yoke 17 and the lid 16, and its upper end portion extends above the yoke 17.
The lower end of the valve rod 12 reaches the inside of the valve chamber 15B, and the valve body 13 is connected to the lower end of the valve rod 12. Disc 1
3 is provided with an engagement protrusion 20 slidably engaged with a guide groove provided in the inner surface of the valve chamber 15B along the axial direction of the valve rod. Further, in the sluice valve 10, the handle 14 has the yoke 1
7 is rotatably supported on the yoke 7 and does not move up and down with respect to the yoke 17, and by rotating the handle 14, the valve rod 12 moves up and down without rotating, so-called "outer screw valve rod non-rotating type" ( It is a sluice valve of JIS B0100 (according to "valve term").

Further, the valve body 13 is of a so-called soft seal type, and a groove is formed in the circumferential direction and the axial direction of the outer peripheral surface of the valve body body 13A, and the elastic packing is joined in a T-shape in the groove. 19 is accommodated, the valve body 13 is moved up and down in the axial direction by the valve rod 12, and the elastic packing 19 is attached to the valve box 1.
The fluid flow path 15A is opened and closed by being pressed against or separated from 1.

In the sluice valve 10, from the viewpoint of ensuring corrosion resistance, the housing 15 constituting the valve box 11,
The lid 16, the yoke 17 and the valve body 13 are made of a synthetic resin material such as PVC, and the valve rod 12 and the nut member screwed with the male screw of the valve rod 12 are made of, for example, stainless steel, brass or the like, and have mechanical strength and corrosion resistance. It is made of a metal with excellent properties.

Next, the overtightening prevention ring will be described.
As shown in FIG. 1, an overtightening prevention ring 30 is attached to a portion inside the yoke 17 of the valve rod 12 so that the vertical position on the valve rod 12 can be adjusted. That is, the overtightening prevention ring 30 is a double nut system in which two nuts are integrally screwed and fixed to a predetermined position of the valve rod 12, or the valve rod 12 is fixed.
A through pin system in which a through hole is provided on the outer peripheral surface of the overtightening prevention ring 30 that is screwed into the valve pin and is fixed to the valve rod 12 with a through pin or a bolt;
The split ring partially cut out or a split ring of two or more splits can be fixed by inserting the cutouts or split rings by bolts. The overtightening prevention ring 30 is preferably made of metal, but may be made of synthetic resin such as FRP or engineering plastic as long as it has excellent mechanical strength such as compressive strength.

Further, a lower valve rod penetrating portion (shaft seal plate 161) in the yoke 17 is formed with a valve closing abutment surface 162 against which the overtightening prevention ring 30 abuts when the valve is fully closed. The portion (sleeve 171) is formed with a valve opening abutment surface 172 with which the overtightening prevention ring 30 abuts when the valve is fully opened.

The height of the inner surface of the yoke 17 is H ₀ , the distance that the valve body 13 moves from the fully closed position to the fully open position is H ₁ ,
The height of the overtightening prevention ring 30 is h, the distance over which the overtightening prevention ring 30 moves into the yoke 17 is H ₂ (see FIG. 2), the compression allowance of the elastic packing 19 is δ, and the creep due to the shutoff force of the valve box 11 is used. When the amount is ε, H ₂ ≉H ₁ + δ + ε, so it is preferable to form the height H ₀ of the inner surface of the yoke 17 so that H ₀ = H ₂ + h.

[Operation of Embodiment] Next, the operation of the gate valve 10 of the present invention shown in FIGS. 1 and 2 will be described. Handle 1
When 4 is turned and turned in the direction to close the valve, the valve rod 12
Lowers, the valve body 13 attached to the valve rod 12 also lowers, and the elastic packing 19 housed in the groove formed on the outer peripheral surface of the valve body main body 13A causes the bottom of the valve box 11 (valve seat) to move. ) And then compressed to a deadline as shown in FIG.

At the same time, the lower surface of the overtightening prevention ring 30 abuts against the abutment surface 162 at the time of valve closing, so that the valve rod 12 does not descend further, and therefore the valve body 13, the valve box 11 and other members have no contact. They are not damaged because they are not overloaded.

As shown in FIG. 1, from the valve closed state, when the handle 14 is held and rotated in the direction to open the valve, the valve rod 1
2 rises, the valve body 13 attached to the valve rod 12 also rises, and the elastic packing 19 accommodated in the groove formed on the outer peripheral surface of the valve body main body 13A is moved to the bottom of the valve box 11 (valve). Seat), and the valve is opened as shown in FIG.

At the same time, the upper surface of the overtightening prevention ring 30 abuts the abutment surface 172 at the time of opening the valve, so that the valve rod 12 does not rise any more, and therefore the valve body 13, the valve box 11 and other members are not lifted. They are not damaged because they are not overloaded.

Further, if the yoke 17 is provided with a window through which the valve rod 12 can be seen and a scale is provided on the outer peripheral surface of the window in the axial direction of the valve rod, the overtightening prevention ring 30 can be used as a partition valve because of its positional relationship with the scale. The opening degree can be discriminated, and the indicator function is also fulfilled.

[0024]

According to the sluice valve of the present invention, when the valve rod is lowered, the valve body comes into contact with the inner surface (valve seat) of the fluid flow path to be fully closed, and at the same time, the overtightening prevention ring is moved to the lower part in the yoke. Since the valve rod cannot be lowered any more as it abuts against the abutting surface formed in the valve rod penetrating portion, the valve disc, the valve rod, the connecting portion of the valve disc and the valve rod, the valve box, the lid, Excessive torque is prevented from being applied to the yoke and the like.

When the valve rod is lifted, the valve body is pulled up to the upper end of the fluid flow path (that is, fully opened), and at the same time, the overtightening prevention ring is formed in the upper valve rod penetrating portion in the yoke. As it cannot hit the abutting surface and raise the valve rod any further, in this case too, excessive torque is applied to the valve disc, the valve rod, the connection between the valve disc and the valve rod, the valve box, the lid, the yoke, etc. Is prevented.

Since the overtightening prevention ring is attached to the inside of the yoke of the valve rod and does not project above the yoke, the length of the valve rod should be shortened by at least the thickness of the overtightening prevention ring. You can

[Brief description of drawings]

FIG. 1A is a side sectional view showing a state of an example of the sluice valve of the present invention when the valve is closed. (B) is a front sectional view showing a state of the sluice valve of the present invention shown in (A) when the valve is closed.

FIG. 2A is a side sectional view showing a state of the gate valve of the present invention shown in FIG. 1 when the valve is opened. FIG. 2B is a front cross-sectional view showing the state of the sluice valve of the present invention shown in FIG. 1 when the valve is opened.

[Explanation of Codes] 10 Gate Valve 11 Valve Box 12 Valve Bar 13 Valve Body 13A Valve Body Main Body 14 Handle 15 Housing 15A Fluid Flow Path 15B Valve Chamber 16 Lid 161 Shaft Seal Plate 162 Valve Closing Face 17 Yoke 171 Sleeve 172 Abutment surface at valve opening 18 Fixing bolt 19 Packing 30 Overtightening prevention ring

Claims (1)

[Claims] 1. A valve box having a fluid channel and a valve chamber extending in a direction perpendicular to the axis of the fluid channel, a yoke for supporting the valve rod on the valve box, and a valve having a screw for moving up and down. In a sluice valve having a rod and a valve element attached to the valve rod to move up and down together with the valve rod to open and close a fluid flow path, an overtightening prevention ring is attached to a portion inside the yoke of the valve rod. An abutting surface is formed in the lower valve stem penetrating portion of the inside where the overtightening prevention ring abuts when the valve is fully closed, and in the upper valve stem penetrating portion in the yoke where the overtightening prevention ring abuts when the valve is fully opened. A sluice valve characterized by having a mating surface.