JP6325855B2 - Check valve - Google Patents

Description

  The present invention relates to an improvement in a check valve which is attached by sandwiching a flange with packing between a pair of pipe members connected by a cap nut.

  2. Description of the Related Art Conventionally, a packing integrated check made by mounting a packing on the outer periphery of a flange formed at one end of a valve box as a check valve for mounting a pipe joint that connects a pair of pipe members and connects with a cap nut. There is a valve (Patent Document 1). This packing integrated check valve clamps the flange between the abutting surfaces of a pair of pipe members, compresses the packing by tightening the cap nut and seals the abutting surface in a watertight manner, and is easy to install. Moreover, it can be attached to existing piping afterwards.

  However, as shown in FIG. 7, in the pipe joint, an annular recess H is formed on the inner periphery of the opening of the butting surface of one tube member P1, and the recess H is formed on the butting surface of the other tube member P2. There is one in which an insertable annular convex portion C is formed. The illustrated pipe joint illustrates the water meter as the primary side, and the annular convex portion C of the secondary side pipe member P2 is inserted into the annular concave portion H of the secondary side connection pipe of the water meter. However, if the above-mentioned packing integrated check valve is attached, the packing may be excessively compressed and deformed at the portion where the annular convex portion C hits, and the packing and the flange may be damaged. is there.

  In view of this, a packing integrated check valve in which an annular convex relief portion is provided in the packing has been proposed (Patent Document 2).

Japanese Utility Model Publication No. 6-12879 JP 2009-115147 A

  According to the packing-integrated check valve of Patent Document 2, the relief portion of the annular convex portion of the pipe member (portion described in terms of the “protrusion made of the front projecting edge” in Patent Document 2) is provided on the packing. Formed and completely prevented the interference between the two. Therefore, since the packing does not adhere to the pipe member at the escape portion, water leakage may occur from a portion sandwiched between the butted surfaces of the pipe member. In particular, since the secondary side of the packing is thick in the axial direction, depending on the tightening torque of the cap nut, the tightening pressure is dispersed and leakage tends to occur. Furthermore, when the check valve of Patent Document 2 is applied to the pipe joint of FIG. 7, when the primary side pipe member P1 is separated from the secondary side pipe member P2 for replacement or maintenance of the water meter, the check valve Is merely sandwiched between the pipe members P1 and P2, the check valve comes out of the secondary side pipe member P2 due to the residual pressure on the secondary side. If it does so, the water discharged | emitted from the secondary side pipe member P2 will accumulate in a meter box, and it will turn into muddy water, but if this muddy water enters the secondary side pipe member P2 again, secondary side piping will be contaminated. .

  The present invention has been made in order to solve the above-described problems. The object of the present invention is to provide a stable and reliable sealing property even in a tube member in which an axial convex portion is formed on a surface sandwiching the packing. Furthermore, it is to provide a check valve that can be held on the secondary side even when the pair of pipe members are separated.

  In order to achieve the above-described object, the present invention provides a valve box having an outward flange formed at one end, a valve seat provided on the one end side of the valve box, and a biasing force in the seating direction in the valve box. The flange having the packing mounted between the pipe ends of a flanged pipe joint that includes a valve body provided on the flange and a packing to be attached to the flange, and a pair of pipe members are connected to each other by a cap nut. A check valve that is mounted with a sandwiched portion formed therein, wherein the packing includes a hollow portion into which an annular convex portion protruding in the axial direction enters the tube end of one tube member, and the opening of the hollow portion On the inner peripheral edge, means for forming a donut-shaped seal portion that is elastically bent and deformed toward the cavity portion by entering the annular convex portion was used.

  According to the above-described means, when a flange with packing is sandwiched between a pair of tube members and the cap nut is tightened, the annular convex portion of one tube member bends the donut-shaped seal portion and the cavity portion side Enter the cavity while pushing into. At this time, the seal part bent and deformed toward the cavity part is brought into close contact with the annular convex part by its elastic restoring force, and water tightness of the gap between the annular convex part and the cavity part is obtained. Further, when the pair of pipe members are separated during maintenance, the residual pressure acts in the direction in which the check valve is released. However, the check valve can be prevented from coming out by the frictional force between the seal portion and the annular convex portion. .

  When the entire circumference of the seal portion is continuous in a donut shape, it may be assumed that the material may be torn due to the pushing of the annular convex portion depending on the material, but the annular convex portion has a frictional force that can prevent the check valve from coming out. If it is the structure closely_contact | adhered to a part, the said tear is in assumption and you may provide one or more slits in the seal part positively beforehand.

  The check valve of the present invention is structurally manufactured through a process of providing a valve seat after the valve body is accommodated in the valve box. At that time, the flange of the valve box has a thick portion on the outer edge. The valve seat is continuously provided with a flared portion that fits into the recessed portion from the outside of the flange on the seat portion on which the valve body is seated. It is preferable that the packing is attached to the flange so as to cover the fitting portion of the flare portion. According to this means, the boundary between the recessed portion of the flange and the flare portion of the valve seat becomes a groove, and packing enters the groove, thereby improving the water tightness.

  Further, the concave portion of the flange of the valve box has a tapered corner on the bottom side, while the flare portion of the valve seat forms a square corner to be fitted on the side that fits into the concave portion, and the flare portion By fusing to the concave portion so that the corner of the corner is heated and melted along the corner of the concave portion, adhesion is not uneven rather than contact with the surface, and the flare portion is Adhesive strength is stable.

  According to the present invention, since the seal portion is provided around the cavity portion of the packing and is folded to the cavity portion side by the annular convex portion of the pipe member, water tightness between the cavity portion and the annular convex portion is obtained. Even when the pipe member is cut off, the check valve can be held by the pipe member provided with the annular convex portion by the friction force.

Explanatory drawing which showed the check valve which concerns on one Embodiment of this invention with the joint (joint disassembled state) Same as above (joint connection state) Expanded sectional view of packing Exploded sectional view of valve box and valve seat Partial enlarged cross-sectional view showing how the packing is mounted Partial enlarged sectional view showing the main part of the flare part and the recessed part Sectional drawing which illustrated the coupling which applies this invention

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. 1 and 2 show the relationship between a check valve and a joint according to an embodiment of the present invention. FIG. 1 shows a state in which the joint is disassembled, and FIG. 2 shows a check valve connected with the joint. It shows the state of mounting. In these drawings, the joint is provided with pipe members P1 and P2 on the primary side (upstream side) and the secondary side (downstream side), and the pair of pipe members P1 and P2 are connected by a cap nut N. . As already described with reference to FIG. 7, in the secondary side pipe member P2, the connecting structure is formed with an annular convex portion C projecting in the axial direction at the pipe end, and the primary side pipe member P1. A concave portion H into which the annular convex portion C fits is formed at the pipe end when the secondary pipe member P2 is directly connected. Note that F is a flange formed on the outer periphery of the pipe end of the secondary side pipe member P2, and is a portion with which the cap nut N is engaged, thereby constituting a flanged pipe joint.

  In contrast to such a joint, the check valve of the present invention includes a valve box 1 having an outward flange 1a at one end, a valve seat 2 provided on the one end side of the valve box 1, and the valve box. 1 is provided with a hemispherical valve body 3 that is urged so as to be seated on the valve seat 2 in a normal state, and a packing 4 that is mounted on the flange 1 a of the valve box 1.

  As shown in detail in FIG. 3, the packing 4 has a mounting groove 4 b for the flange 1 a formed on the primary side of the cylindrical main body 4 a having a thickness in the axial direction. The inner diameter on the secondary side of the mounting groove 4b is made larger than the outer diameter of the annular convex portion C of the secondary side pipe member P2, thereby forming a hollow portion 4c into which the annular convex portion C enters. Furthermore, a seal portion 4d made of a donut-shaped thin wall having a smaller central hole than the opening is formed at the opening on the secondary side end face of the cylindrical body 4a, that is, the inner peripheral edge of the opening of the cavity 4c.

  According to the check valve equipped with the packing 4, as shown in FIG. 2, the inward flange-like seal portion 4d is elastically moved toward the cavity portion 4c by the annular convex portion C of the secondary side pipe member P2. It bends and deforms. Accordingly, the end surfaces of the pipe members P1 and P2 are sealed by both ends of the cylindrical body of the packing 4a, and the annular convex portion C is also sealed by the seal portion 4d. Therefore, the sealing performance is ensured for the entire end faces of the pipe members P1 and P2 including the annular convex portion C.

  In addition, in the state of FIG. 2, a frictional force acting in the axial direction acts between the seal portion 4d and the annular convex portion C. Therefore, when the pipe members P1 and P2 are separated, the check valve is provided with the annular convex portion C. Even if residual pressure is generated in the secondary side pipe member P2 and the secondary side pipe member P2 has a residual pressure toward the primary side, the check valve is pulled out of the secondary side pipe member P2 by the frictional force. Can be prevented. This is advantageous when the primary side pipe member P1 is made of a water meter as shown in the figure and is separated from the secondary side pipe member P2 for maintenance such as meter replacement. The check valve is left in the secondary side pipe member P2 at the time of disconnection, thereby preventing water from being discharged from the secondary side pipe member P2 into the meter box. As a result, dirty water in the meter box can be prevented. This is because the secondary side pipe member P2 does not contaminate the secondary side pipe.

  FIG. 4 shows, as a more preferred embodiment, an enlarged view in which the valve box 1 and the valve seat 2 are exploded, and the flange 1a of the valve box 1 leaves the thick part 1b on the outer edge, and the inside of the thick part 1b. On the other hand, the valve seat 2 expands the primary side of the seat portion 2a on which the valve body 3 is seated, and the flare portion 2b fitted to the recess portion 1c is continuously formed from the outside of the flange 1a. Is formed.

  As shown in FIG. 5, the packing 4 covers the fitting portion of the flare portion 2b and is attached to the flange 1a. As a result, the packing 4 bites into a minute groove 5 (see a circular enlarged portion shown by a one-dot chain line in FIG. 5) formed at the boundary between the flare portion 2b and the recessed portion 1c due to compression when the joint is connected, and is watertight and watertight. Improves. The flange 1a is sandwiched between a pair of pipe members P1 and P2 and continues to be subjected to compressive stress through the packing 4. However, since the portion where the stress acts is constituted by the integral thick portion 1b, the stress Strength and durability against is improved.

  By the way, since the seating biasing force of the valve body 3 acts on the valve seat 2, it is necessary to permanently fix the flare portion 2b to the flange 1a. As the means, it is possible to use an adhesive having water resistance, but it takes a long time until the adhesive is solidified, and during that time, the valve seat 2 is resisted against the urging force of the valve body 3. Productivity is poor due to the time and effort required to press it.

  Therefore, it is advantageous that the flare portion 2b is fused to the flange 1a by ultrasonic heating. However, in the fusion method, unevenness is likely to occur depending on the shape of the member, and it is difficult to obtain a stable adhesive strength.

  Therefore, in this embodiment, as shown in FIG. 6, the recessed portion 1c of the flange 1a forms a corner corner 1d on the bottom side in a tapered shape, while the flare portion 2b is a corner corner on the side fitted into the recessed portion 1c. 2c was formed at a right angle, and the flare portion 2b was fused to the recessed portion 1c by heating with ultrasonic waves or the like so that the corner 2c melts along the tapered corner 1d of the recessed portion 1c. Thereby, since the corners 2c and 1d are preferentially fused, adhesion is not uneven and stable adhesion strength can be obtained as compared to the surface where the portions are fused in the same shape.

DESCRIPTION OF SYMBOLS 1 Valve box 1a Flange 1b Thick part 1c Recessed part 1d Corner corner (tapered corner) of the bottom side of a recessed part
2 Valve seat 2a Seat part 2b Flare part 2c Flare part corner 3 Valve body 4 Packing 4a Cylindrical body 4b Mounting groove 4c Cavity part 4d Seal part 5 Groove at the boundary between the recessed part and the flare part

Claims (2)

A valve box having an outward flange formed at one end thereof, a valve seat provided at the one end side of the valve box, a valve body provided by urging in the seating direction in the valve box, and a flange mounted With packing,
A check valve that is attached by sandwiching the flange with the packing between the pipe ends of a flanged pipe joint that butts the pipe ends and connects a pair of pipe members with a cap nut,
In the packing, while forming a hollow portion into which an annular convex portion protruding in the axial direction enters the tube end of one tube member,
On the inner peripheral edge of the opening of the hollow portion, a donut-shaped seal portion is formed that elastically bends and deforms toward the hollow portion by entering the annular convex portion ,
The flange of the valve box is formed by forming a recessed portion inside the thick portion, leaving a thick portion on the outer edge, while the valve seat is formed on the seat portion on which the valve body is seated from the outside of the flange. A check valve characterized in that a flare portion to be fitted into the recessed portion is provided continuously, and a packing is attached to the flange so as to cover the fitting portion of the flare portion . The concave part of the flange of the valve box has a tapered corner on the bottom side, while the flare part of the valve seat forms a square corner on the side that fits into the concave part, and the flare part is heated by heating. the check valve according to claim 1, wherein the corner is fused to the recessed portion so as to melt along the corners of the recessed portion.

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