JPH0611051A - Sluice valve - Google Patents

Abstract

PURPOSE:To exchange packing in the condition of using a sluice valve, and reduce water leak compared with customary packing. CONSTITUTION:This sluice valve is constituted so that a valve stem 3 is threadedly engaged with a valve body 2, the valve body 2 is moved from the full closing position to the full opening position following to rotating the valve stem 2, the valve shaft hole 9 of a valve box 1 is sealed by a sealing part arranged around the valve stem 3, and the valve stem 3 is rotationally movably held with a thrust ball bearing 18 provided on the upper part of a packing box 11. The circumferential edge part of the valve shaft hole 9 of the valve box 1 is formed into a seat part 8, the valve stem 3 is formed with a stepped part 7 to make contact with the seat part 8 so as to close the valve shaft hole 9, and an 4 O-ring 12 is provided on the circumferential edge part of the valve stem 3 for preventing water leak from the valve shaft hole 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sluice valve with a bearing, for example, in which a plate-shaped valve element slides in a direction perpendicular to the direction of fluid to open and close a fluid passage.

[0002]

2. Description of the Related Art FIG. 2 is a partial sectional view of a gate valve,
In this figure, 31 indicates a valve box, and this valve box 31 is
It is composed of a valve box main body 32 and a valve lid 33 attached to the upper part of the valve box main body 32. A stand 34 is attached to an upper portion of the valve lid 33.
A packing box 35 is provided in the center of the lower part of the valve 4, and a valve rod 37 is inserted into a valve shaft hole 36 provided in the packing box 35. A packing 38 such as wooly nylon, which is a seal portion, is fitted between the valve rod 37 and the packing box 35, and is pressed by a packing presser 39 from the upper side to form the valve shaft hole 3
Water leakage from 6 is blocked. A bearing case 40 is provided above the stand 34, and a thrust ball bearing 41 is provided.
Is stored. A valve rod 37 is rotatably held by the thrust ball bearing 41 via a thrust collar 42.

A disc-shaped valve body 43 is attached to the lower portion of the valve rod 37, and the valve body 43 opens and closes in the valve box 31 from a fully closed position to a fully open position.

[0004]

However, in the conventional sluice valve described above, the packing 38 can be replaced when the pressure of the fluid is not present in the sluice valve, but when the fluid is flowing, the valve shaft hole can be replaced. Since fluid leaks from 36, the packing 38 cannot be replaced when the sluice valve is in use.

Further, since the gland type packing 38 such as woolly nylon may leak, the packing 38
And the thrust ball bearing 41 must be separated,
There was also the problem that the sluice valve had to be raised that much.

The present invention has been made in order to solve the above-mentioned conventional problems, and the packing can be replaced when the sluice valve is in use, and there is no water leakage from the valve shaft hole. The purpose is to provide a low gate valve.

[0007]

According to the sluice valve of the present invention, a valve rod is screwed with a valve body, and the valve body opens and closes from a fully closed position to a fully opened position as the valve rod rotates. In a sluice valve in which the valve shaft hole of the valve box is sealed by the seal portion arranged around the rod and the valve rod is rotatably held by the valve rod holding portion provided above the seal portion, The peripheral portion serves as a seat portion, and a step portion that abuts the seat portion to close the valve shaft hole is formed on the valve rod.

Further, in the sluice valve of the present invention, the O-ring seal portion for preventing water leakage from the valve shaft hole is provided on the peripheral portion of the valve rod. Further, in the sluice valve of the present invention, the packing box in the upper part of the valve box is formed with a water drain hole for detecting water leakage from the valve shaft hole.

[0009]

With the above structure, when the valve rod is further rotated in the opening direction from the fully opened position of the valve body, the valve body rises and the upper portion of the valve body comes into contact with the valve lid. When the valve rod is rotated in the closing direction in this state, the valve rod descends, the step portion of the valve rod comes into contact with the seat portion to close the valve shaft hole, and the upward leakage of water from the valve shaft hole is stopped. Therefore,
Since the O-ring of the O-ring seal portion can be replaced, the O-ring can be replaced even when the sluice valve is used (the pressure is in the sluice valve). In addition, since the O-ring seal portion is provided on the outer peripheral portion of the valve rod, water can be completely stopped from the valve shaft hole, and the height of the sluice valve can be kept low.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a partial sectional view of a sluice valve with a bearing according to the present invention.

In the sluice valve of this embodiment, a disc-shaped valve element 2 is housed in a valve box 1, and the valve element 2 moves up and down in the valve box 1 along a valve rod 3. Basically, the structure is almost the same as that of the conventional sluice valve with a bearing.

The valve box 1 is composed of a valve box body 4 and a valve lid 5, and a flange portion 6 composed of an inward flange and an outward flange is formed on an upper portion of the valve lid 5. The inward flange 6A serves as a seat portion 8 against which a step portion 7 of the valve rod 3 described later abuts. The seat portion 8 is formed so as to slightly project in the radial direction of the valve shaft hole 9. The seat portion 8 does not necessarily have to be integrated with the flange portion 6.

A packing box 11 is attached to the flange portion 6 above the valve lid 5 with screws (not shown). A valve shaft hole 9 is formed vertically in the center of the packing box 11, and an O-ring 12 with an O-ring 12 is provided at the peripheral edge of the valve shaft hole 9.
A fitting hole 14 for fitting the ring case 13 (corresponding to the O-ring seal portion) is provided around the ring case 13. Fitting hole 14
Water leakage from the valve shaft hole 9 can be more completely stopped by the O-ring case 13 fitted in. In addition, the height of the packing box 11 can be lowered by completely stopping the water by the O-ring case 13, so that the height of the entire sluice valve can be lowered.

A drain hole 15 for detecting leak water from the valve shaft hole 9 is formed through the upper wall portion of the packing box 11.
A flange portion 16 is formed on an upper portion of the packing box 11, and a bearing case 17 corresponding to a valve rod holding portion is attached to the flange portion 16 with a screw (not shown). A thrust ball bearing 18 is fitted in the bearing case 17. The valve rod 3 is rotatably held by the thrust ball bearing 18 via a thrust collar 19. Reference numeral 20 is a nut provided on the upper portion of the thrust ball bearing 18.

The valve rod 3 has the bearing case 17, the packing box 11 and the valve lid 5 inserted therethrough, and the lower end portion reaches the central portion of the valve box body 4. The valve rod 3 has a male screw 21 formed from the center to the lower end. The female screw piece 22 of the valve body 2 is screwed onto the male screw 21 of the valve rod 3, and the valve body 3 is attached to the female screw piece 22.

A step portion 7 is formed slightly above the upper end of the male screw 21 of the valve rod 3. The step portion 7 has a diameter such that it can abut the seat portion 8 and close the valve shaft hole 9. Next, the operation of the above configuration will be described.

The rotation of the valve rod 3 causes the female screw piece 22 screwed to the male screw 21 to move up and down. As the female screw piece 22 moves vertically, the valve body 2 attached to the female screw piece 22 is fully opened from the fully closed position. It can be opened and closed depending on the position.

When the seal of the O-ring 12 becomes insufficient and water needs to flow out from the water drain hole 15 to replace the O-ring 12, or when the O-ring 12 is to be replaced regularly, first, the valve of FIG. When the valve rod 3 is further rotated in the opening direction from the fully opened position of the body 2, the valve body 2 rises, the upper portion of the valve body 2 contacts the valve lid 5, and the valve rod 3 cannot rotate. Bearing case 17, nut 20, thrust collar 1 in that state
When 9 is removed, further rotation of the valve stem 3 is possible. Then, when the valve rod 3 is rotated in the opening direction, the valve rod 3 descends, the step portion 7 of the valve rod 3 contacts the seat portion 8, and the rotation of the valve rod 3 is stopped. When the step portion 7 of the valve rod 3 contacts the seat portion 8 and closes the valve shaft hole 9, the upward leakage of water from the valve shaft hole 9 is stopped, so that the packing box 11 is removed and the O-ring is removed. Remove the case 13 and replace the O-ring 12. This O-ring 12 can be replaced even if a sluice valve is used.

In the reassembly, the O-ring case 13, the packing box 11, the thrust collar 19, the nut 20, and the bearing case 17 are assembled in the order opposite to the above order.

[0020]

As described above, according to the present invention, the step portion formed on the valve rod abuts the seat portion to close the valve shaft hole, so that the O-ring is used even when the sluice valve is in use. The seal part can be replaced. Further, the O-ring seal portion ensures the sealing of the valve shaft hole, and further, the height can be made lower than that of the conventional gate valve.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a gate valve according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a conventional gate valve.

[Explanation of symbols]

 1 valve box 2 valve body 3 valve rod 5 valve lid 7 step section 8 seat section 9 valve shaft hole 11 packing box 12 O-ring 13 O-ring case 15 drain hole

Claims (3)

[Claims] 1. A valve body is screwed with a valve body, and the valve body opens and closes from a fully closed position to a fully open position as the valve rod rotates, and a valve box is provided by a seal portion arranged around the valve rod. In a sluice valve that seals the valve shaft hole of, and rotatably holds the valve shaft by the valve shaft holding part provided in the upper part of the seal part, the peripheral part of the valve shaft hole of the valve box serves as a seat part and A sluice valve having a step portion that abuts on the seat portion and closes the valve shaft hole. 2. The sluice valve according to claim 1, wherein an O-ring seal portion for preventing water leakage from the valve shaft hole is provided on a peripheral portion of the valve rod. 3. The sluice valve according to claim 2, wherein a packing box in the upper part of the valve box is formed with a water drain hole for detecting water leakage from the valve shaft hole.