JPH1137310A - Cut-off valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the drop of a packing which is kept into contact with a valve seat in a cut-off valve mounted on the way of a channel, and improve the sealing performance. SOLUTION: A groove part 3 is formed on a position opposite to a valve seat 2 of a valve element 1, and a packing 4 of double structure formed by binding water expansible urethane 4a which is expanded when it absorbs the water, and a non-expansible urethane 4b which is not expanded, by the polymerization, is mounted on the groove part 3. Further the packing 4 is pressed by a box nut 6, and the loosening of the box nut 6 is prevented by a caulking pin 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water shutoff valve which is used in the middle of a water channel such as seawater.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing a general valve structure, and schematically shows an on-off valve mounted in a flow path of water flowing in the direction of the arrow in the figure.

In this on-off valve, a valve body 102 is provided in a valve box 101, and a rubber ring 103 fixed in a lower peripheral direction of the valve body 102 is brought into pressure contact with a valve seat 104 as packing. When the valve stem 105 attached to the upper part moves in the vertical direction in the figure by operating a handle (not shown), the rubber ring 103 and the valve seat 1 are moved.
04 comes off or comes into pressure contact, which causes water to flow or stop.

FIG. 4 is a view showing the structure of such a conventional water shutoff valve. FIG. 4A is a sectional view showing the structure of the valve, and FIG. 4B is a perspective view showing the shape of the packing. In the figure, reference numeral 11 denotes a valve body, and a ring-shaped rubber 12 is fixed to the lower portion by baking, and this rubber 12 comes into contact with a valve seat (not shown).

FIG. 5 is a view showing the structure of another conventional water shutoff valve, in which (a) is a sectional view showing the valve structure, (b) is a perspective view showing the shape of the packing, and (c). FIG. 4 is a perspective view showing the shape of a packing holding nut. FIG. 5 shows an example in which a disc-shaped rubber 12 is put in a valve body 11 and fastened by a nut 13. A split pin 14 is inserted into a pin hole 15 to prevent the nut 13 from loosening.

[0006]

However, the conventional water shutoff valve as described above has a problem that the rubber packing falls off with the passage of time, the sealing property is reduced, and the reliability is lacking. There was a point.

That is, in the case where rubber is baked on the valve body, the rubber may fall off due to the tightening between the valve seats with the passage of time. Also, when rubber is inserted into the valve body and tightened with a nut, the split pin of the detent of the nut may be corroded and run off.At the same time, the nut loosens and the rubber falls off. ,
The bolt (screw) of the valve body also corrodes. Further, since the rubber is compressed by the valve body and the valve seat, the rubber may be deformed and come off the outer peripheral frame of the valve body.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a water shutoff valve which can prevent the packing from falling off, has an improved sealing property, and has improved reliability. And

[0009]

SUMMARY OF THE INVENTION A water stop valve according to the present invention comprises:
It is configured as follows.

(1) A water stop valve interposed in the middle of a water channel, wherein a groove is formed at a position facing a valve seat of a valve body, and a water-expandable urethane that absorbs moisture and expands in the groove. A two-layer packing in which non-expandable non-expandable urethane was bonded by polymerization was interposed.

(2) In the valve of the above (1), a portion of the packing that comes into contact with the valve seat is projected toward the valve seat.

(3) In the valve of (1) or (2), the outer end of the groove of the valve body is bent inward.

(4) In any one of the above-mentioned valves (1) to (3), the packing is pressed by a cap nut from outside the groove.

(5) In the valve of (4), a caulking pin is used as a detent pin for the cap nut.

[0015]

FIG. 1 is a sectional view showing the structure of an embodiment of the present invention, and shows the internal structure of a water stop valve interposed in the middle of a water channel as shown in FIG.

In FIG. 1, reference numeral 1 denotes a valve body, and a groove 3 is formed at a position facing the valve seat 2, and a water-expandable urethane 4a which absorbs water and expands and a non-expandable non-expandable groove 3 A two-layer packing 4 in which urethane 4b is bonded by polymerization is interposed with the water-expanded urethane side facing the valve seat (lower side).

The outer end of the groove 3 of the valve body 1 is bent inward so that the packing 4 does not protrude.
And the packing 4 is placed outside the groove 3 (lower side).
The cap nut 6 is used as a detent pin for the cap nut 6.
The caulking pin 7 is inserted into the pin hole 8 of the cap nut 6 together with the adhesive so as to caulk from both sides. And
The packing 4 and the valve seat 2 are moved by the vertical movement of the valve stem 9 in the figure.
As shown in FIG. 3, the flow of water can be stopped or made to flow by separating or coming into contact with each other.

FIG. 2 is a sectional view showing the shape of the packing 4. In FIG. 1A, as shown in FIG. 1, a portion that comes into contact with the valve seat 2 is made to protrude, and the protruding portion 4c comes into pressure contact with the valve seat 2. The one shown in (b) is a flat two-layer packing 4. It should be noted that the water-expandable urethane 4a and the non-expandable urethane 4b of the packing 4 may be either upper or lower, but preferably have the relationship shown in the figure.

In the water stop valve having the above structure, the gasket 4 is inserted into the valve body 1 by providing the groove 3 with the gasket 4. Is in a good contact state. At this time, the outer peripheral frame of the valve body 1 has a groove structure that does not protrude from the groove portion 3 even when the rubber (the packing 4) is compressed and deformed.

Further, the threaded portion of the valve element 1 screwed with the cap nut 6 for holding the packing 4 does not come into contact with water or other liquid when the cap nut 6 is attached. The detent pin of the cap nut 6 is the caulking pin 7 as described above, and the pin hole 8 of the cap nut 6 is filled with an adhesive and caulked from both sides. For this reason, the threaded portion of the valve body 1 is hardly corroded.

Here, in the water stop valve of this embodiment, a packing 4 having a two-layer structure made of urethane rubber is used, and the shape of the packing 4 is strengthened by the non-expandable urethane 4b on one side. , And water-swelling urethane 4
a is added and tightened with the cap nut 6. After that, the contact with water causes the water expansion function to function, thereby increasing the adhesion to the cap nut 6, and at the same time preventing the corrosion of the threaded portion of the valve body 1.

By using the water-swelling rubber as the valve seat rubber (packing 4) in this way, it is possible to prevent the valve from falling off from the groove portion 3, and at the same time, the sealing performance of the valve is increased.
Reliability is improved.

In the past, molds of various sizes were required for manufacturing the packing, and in addition, machining was required in some cases, which was expensive. However, the flat packing 4 of the composite product of the water-expandable urethane 4a and the non-expandable urethane 4b in the present embodiment does not require a mold, and centrifugally molds two layers of urethane rubber by a centrifugal molding drum.
Then, it can be manufactured by punching, and it is inexpensive.

Further, in the packing 4 having the two-layer structure, the water-expandable urethane 4a and the non-expandable urethane 4b can be bonded by polymerization, so that both layers do not separate. Therefore, the characteristics of the urethane become extremely strong.

[0025]

As described above, according to the present invention, it is possible to prevent the gasket coming into contact with the valve seat from falling off, to increase the sealing performance, and to improve the reliability.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the shape of a packing according to one embodiment.

FIG. 3 is a sectional view showing a general valve structure.

FIG. 4 is a configuration diagram showing a conventional example.

FIG. 5 is a configuration diagram showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve body 2 Valve seat 4 Packing 4a Water expansion urethane 4b Non-expansion urethane 4c Projection part 5 Bending part 6 Cap nut 7 Caulking pin 8 Pin hole 9 Valve stem

Claims (5)

[Claims] 1. A water stop valve interposed in the middle of a water channel,
A groove is formed at a position opposing the valve seat of the valve body, and a two-layer packing in which a water-expandable urethane that absorbs moisture and expands and a non-expandable urethane are bonded by polymerization is interposed in the groove. A water shutoff valve characterized by the fact that it is formed. 2. The water stop valve according to claim 1, wherein a portion of the packing that comes into contact with the valve seat protrudes toward the valve seat. 3. The water stop valve according to claim 1, wherein an outer end of the groove of the valve body is bent inward. 4. The water stop valve according to claim 1, wherein the packing is pressed from outside the groove by a cap nut. 5. The water stop valve according to claim 4, wherein a caulking pin is used as a detent pin for the cap nut.