JP2002276833A - Valve element and check valve using this - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a sealing property, i.e., a reverse flow preventing property, to make an operability of a valve element good, to set a flow characteristic to the optimum condition and to effectively exhibit a reverse flow prevention pressure resistant property. SOLUTION: The valve element 1 opens/closes a flow passage by contacting/ leaving with a valve seat 3 formed on a body 6. This valve element 1 is a valve element for a check valve constituted by a surface layer 2 closely contacted with the valve seat 3; and an encroaching preventing part, provided on an inner layer part of this surface layer 2, for preventing that the surface layer 2 is encroached to the valve seat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve element used for piping of upper, middle, sewage, agricultural water, industrial water, drainage and other liquids, oil and gas, and a check valve using the same. In particular, the present invention relates to a ball check valve used in the middle of piping such as tap water.

[0002]

2. Description of the Related Art This type of ball check valve is widely used because the contact portion of a valve body with a valve seat is different for each operation (see, for example, Japanese Utility Model Application Laid-Open No. 52-98233). . In particular, in this check valve, the structure of the valve element that occupies an important position includes a rubber spherical valve element formed only of rubber, and a resin spherical valve element formed only of resin. Spherical valve bodies and the like, in which aluminum is used as a core material and covered with rubber, are known.

[0003]

However, the structures of these conventional valve elements have respective problems.
First, since the rubber spherical valve body is thick only with the rubber layer, the sealing pressure causes indentations on the valve body surface, the valve body bites into the valve seat, and affects the sealing performance and operability, It will no longer function as a valve. Further, the resin spherical valve body is harder than the rubber material, and the valve body itself does not fit into the valve seat. Therefore, there are disadvantages such as poor sealing with the valve seat and generation of noise.

In the case of a valve body in which the outer periphery of a core material is covered with rubber or the like, if the weight of the valve body itself is heavy, the operability is poor and the pressure loss is large. On the other hand, if the weight of the valve body is light, Since the valve element is easy to move, the sealing property and the flow characteristics become unstable. In this case, in particular, there is a problem that the differential pressure becomes extremely unstable in a low flow rate region.

SUMMARY OF THE INVENTION The present invention has been developed in order to solve the conventional problems at a time. The object of the present invention is to secure the sealing performance for preventing backflow and to improve the operability of the valve element. It is another object of the present invention to improve the flow rate characteristics under optimum conditions and to effectively exhibit the backflow prevention withstand pressure performance.

[0006]

Means for Solving the Problems In order to solve the above problems, the invention according to claim 1 is a valve element which opens and closes a flow path by separating from and coming into contact with a valve seat formed on a body. The valve body includes a surface layer that is in intimate contact with the valve seat, and a bite prevention portion that prevents the surface layer from biting into the valve seat at an inner lower layer portion of the surface layer.

In this case, the valve body may have a weight adjusting portion for adjusting the weight of the valve body formed in the lower inner layer portion of the bite prevention portion. As in the invention according to the third aspect, it is preferable that the bite prevention portion and the weight adjustment portion are arranged in a uniform state inside the surface layer.

Further, as in the invention according to claim 4, the surface layer can be made of rubber, the bite prevention portion is made of resin, and the weight adjusting portion is made of metal, and the valve body is spherical. A ball valve or a piston-shaped valve is preferable.

According to a sixth aspect of the present invention, a valve seat is provided inside a body having a primary side opening and a secondary side opening, and the valve body is retracted from the valve seat into a body closer to the secondary side. An inclined path is provided, and the valve element according to any one of claims 1 to 5 is incorporated in the inclined path so as to be freely guided, and the valve element is separated from and brought into contact with the valve seat to open and close the flow path. This is a check valve.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a valve body and a check valve incorporating the same according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows a check valve incorporating a ball-shaped valve element. The surface layer 2 of the valve element 1 is formed of an elastic material such as rubber or soft resin. It is formed of a rubber layer such as ethylene-propylene or EPDM such as EPDM. The surface layer 2 is desirably set to a thickness that ensures adhesion to the valve seat 3 described later, and is desirably provided as thin as possible. Inside the surface layer 2, there is provided a bite prevention part 4 for preventing the surface layer 2 from biting into the valve seat 3. In this example, the bite prevention part 4 is formed of a resin material of φ33 mm. I have. Further, a weight adjusting portion 5 for adjusting the weight of the valve element 1 is provided at a central concentric portion of the bite preventing portion 4 as shown in FIG. The weight adjusting section 5 is formed of a metal such as iron.

FIG. 3 shows another example of the bite preventing portion 4 and the weight adjusting portion 5 provided inside the surface layer 2. According to the figure, the bite prevention unit 4 and the weight adjustment unit 5 are mixed and arranged in a uniform state. In this case as well, the bite prevention unit 4 and the weight adjustment unit 5 are similar to the above example. Plays each function.

In the present embodiment, the surface layer 2 is made of rubber, the bite preventing portion 4 is made of resin, and the weight adjusting portion 5 is made of resin.
Is formed of a metal, and a combination thereof is preferable.

Next, the check valve shown in FIG. 1 will be described. The body 6 having the opening 6a on the primary side and the opening 6b on the secondary side is molded from a casting of bronze, brass, stainless steel or the like. In the present embodiment, female screws 7a and 7b are formed in the openings 6a and 6b, respectively, but may be piping connections such as male screws and flanges.

A valve seat 3 is provided in the body 6 at an angle of 45 ° with respect to the pipe shaft 8 near the primary side, and the inner peripheral surface of the valve seat 3 is It has an inner weight surface 9 of approximately 50 ° with respect to the central axis 3a. Further, the vertical projection cross-sectional area Y (diameter y) of the valve seat 3 is formed so as to be equal to or larger than the pipe cross-sectional area X (diameter x) to suppress the pressure loss and improve the flow rate characteristics in the low flow rate region. I am trying to be stable.

Further, a ramp 10 having an inclination of 45 ° with respect to the pipe shaft 8 is integrally formed in the body 6 from the valve seat 3 to the secondary side opening 6b, so that a positive pressure state, that is, the fluid is in a primary pressure state. When flowing from the side to the secondary side, it is a flow path for retracting the valve element 1. Further, as shown in FIG. 2, a guide portion 11 is provided in a state parallel to the central axis of the valve seat 3 so as to guide the valve element 1 freely. The guide portion 11 may be provided in a single line, but by appropriately providing two or more lines, the wobble of the valve body 1 can be prevented. In the drawing, reference numeral 17 denotes a lid which is screwed onto the opening of the ramp 10 of the body 6 to cover.

Next, the operation of the above embodiment will be described. In the state shown in FIG. 1, the valve element 1 exhibits a backflow preventing function while ensuring the sealing property of the valve seat 3. Next, when a fluid such as water flows in a positive pressure state, the valve element 1 is not in a state of being cut into the valve seat 3, and is smoothly separated from the valve seat 3 to be guided to the guide portion 11 while operating. On the ramp 1
Since the valve opening of the valve seat 3 is opened by retreating to 0, pressure loss is suppressed, and optimal flow characteristics can be obtained, and flow characteristics are stable even in a low flow region.

In particular, since the vertical projection cross-sectional area Y of the valve seat 3 is set to be equal to or greater than the pipe cross-sectional area X, the operability of the valve element 1 is good, and the sealing performance and flowability are stable. It can be operated in a state where it is set.

FIG. 5 shows another example of the valve element. The valve element 12 has a cylindrical shape and a piston shape, and a tapered surface 13 is formed on a sealing surface which is in close contact with the valve seat 3. ing. The internal structure of the valve element 12 is substantially the same as that of the valve element 1 described above, and the operation and effect thereof are also the same.

The valve element 12 shown in FIG. 1 has a thin surface layer (rubber layer) 14 and an anti-biting portion (resin layer) 15 therein.
, And a weight adjusting portion (metal layer) 16 is provided at the center. In addition, the bite prevention part 15 is provided inside the surface layer 14.
And the weight adjustment unit 16 may be arranged in a uniform state.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a valve body and a check valve incorporating the same according to the present invention will be described below. The size of the check valve in FIG. 1 is 25 A, the ball diameter of the valve body 1 is φ35 mm, and the surface layer 2 is a rubber layer. It is desirable to set the thickness as thin as possible. The thickness is set to an appropriate thickness that ensures adhesion to the valve seat 3 while preventing the contact with the valve seat 3. In this example, the thickness of the surface layer 2 is 1 mm.

The weight adjusting section (metal layer) 5 is provided with a valve body 1.
Is set to a predetermined weight, the dimensions are appropriately set. In this example, the metal diameter is φ18 mm, and the valve element 1
Weighs about 40 g. By the way, the rubber layer 2 is about 4 g,
The resin layer 4 weighs about 12 g, and the metal layer 5 weighs about 24 g.

The operation test of the valve element 1 of the check valve according to the present invention was performed in accordance with JWWA B129 (standard for check valve for water supply). In this test, first, the pressure on the primary side was set to 0, and 1.5 MPa (15.3 kgf / m
m ² ) is applied and maintained for 10 minutes, then the secondary pressure is released. Next, when the pressure is gradually applied from the primary side, the pressure when the valve element 1 separates from the valve seat is confirmed. The ball diameter of the sample is φ35 mm, and the rubber material is EPT. Table 1 shows the valve operation test results.
Shown in

[0023]

[Table 1] In the all rubber ball of the comparative example, No. A1-A
Even if the hardness of the rubber is changed as shown in FIG. 2, the valve body 1A bites into the valve seat 3A as shown in FIG.
If 0 kPa (10 kgf / mm ² ) or more is not added,
The valve body 1A could not be separated from the valve seat 3A. Next, in the case of all resin balls, As shown in B1, although the valve element 1 was separated from the valve seat 3 even with a slight positive pressure, the subsequent movement of the valve element 1 became unstable, and the impact sound generated when the valve element 1 hit the inside of the body was confirmed. Was done. In addition, when this all-resin ball is used, the secondary side water pressure is 1.3.
0 to 0.42 MPa (13.2 to 4.4 kgf / m
m ² ) for about 15 seconds in a sheet leak test,
A sheet leak of about 5 cc / min has been confirmed. On the other hand, in the case of a cored rubber ball having a core diameter of φ25 mm, 300 to 50
At a positive pressure of 0 kPa (3 to 5 kgf / mm ² ) or more, the valve element 1 was separated from the valve seat 3. This tendency is shown in C1 ・ C2
The same was true even when the material of the core was changed as shown in C3. However, when the valve of the present invention is actually used for piping such as tap water, the valve body 1 may operate at a lower positive pressure. Desired.

Here, No. The core diameter is φ as shown in C4.
If it is 33 mm, the phenomenon of biting into the valve seat 3 is not seen,
Positive pressure 10 to 20 kPa (0.1 to 0.2 kgf / m
m ² ), the valve element 1 was operated, an appropriate valve opening operation was obtained, and it was also confirmed that there was no leakage in the above-described seat leakage test separately performed. Further, the ball of the sample C4 was provided with a weight adjusting portion in the present example No. As a result of the test on No. 1, no phenomenon of biting of the valve element 1 into the valve seat 3 was observed, and the check function was satisfied, and a state in which the differential pressure was stable even in a low flow rate region was confirmed.

The results are shown in the graph of the flow characteristic comparison in FIG. As shown in FIG.
Although there is a possibility that the valve body 1 fluctuates, the valve element 1 according to the embodiment of the present invention shows a stable state even in the low flow rate range, and further, when the flow rate is increased, the differential pressure is increased. Was stable and tended to increase steadily with the flow rate. On the other hand, according to Comparative Example C4, an unstable state was observed in which the numerical value of the differential pressure fluctuated in the low flow rate range.

In the check valve of this embodiment, the valve seat 3 is formed at an angle of 45 ° with respect to the pipe shaft 8 so that it can be used for both horizontal and vertical pipes. The valve seat 3 is formed in parallel with the central axis 3a. In the valve formed by inclining the valve seat with respect to the center axis of the flow path, the flow path is bent, so that the pressure loss increases. However, the check valve according to the present embodiment is configured as shown in FIG. , The vertical projection cross-sectional area of the valve seat 3, that is, the area Y obtained by projecting the area of the inclined valve seat 3 onto a plane orthogonal to the flow path central axis 8.
(About 494mm ² in this example), (in this example, about 490 mm ²⁾ pipe cross-sectional area X and be equal to or higher than equivalent straight line from the fluid primary-side opening 6a to the secondary side opening 6b A large flow rate is ensured to suppress the pressure loss of the fluid, and the flow characteristics are stabilized even in a low flow region.

[0027]

As is apparent from the above, it is possible to minimize the influence of indentations on the surface layer while ensuring the sealing performance with the valve body, and to reliably prevent the generation of noise. it can. It is also possible to obtain a check valve that reliably prevents biting of the valve body into the valve seat and has excellent flow characteristics, good operability, small pressure loss, and excellent durability. It has effects such as being able to do.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a valve element and a check valve incorporating the same in the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view showing another example of the valve body shown in FIG. 1;

FIG. 4 is an explanatory diagram showing a vertical projection sectional area and a pipe sectional area of a valve seat according to the present invention.

FIG. 5 is a longitudinal sectional view showing another embodiment of the present invention.

FIG. 6 is a graph showing a flow characteristic comparison between a check valve according to the present invention and a conventional check valve.

FIG. 7 is a cross-sectional view showing a state of a valve body in a low flow rate region of the check valve.

FIG. 8 is a longitudinal sectional view showing a state of an operation test of the all-rubber ball valve element of the comparative example.

[Description of Signs] 1 valve body 2 surface layer 3 valve seat 4 bite prevention section 5 weight adjustment section 6 body 6a, 6b opening 8 flow path 10 ramp

Claims (6)

[Claims] 1. A valve body which opens and closes a flow path by being separated from and brought into contact with a valve seat formed on a body, the valve body includes a surface layer which is in close contact with the valve seat, and a lower surface layer inside the surface layer. A valve body comprising: a bite prevention portion for preventing a layer from biting into a valve seat. 2. The valve body according to claim 1, wherein a weight adjusting portion for adjusting the weight of the valve body is formed in an inner lower layer portion of the bite prevention portion. 3. The valve body according to claim 1, wherein a bite preventing portion and a weight adjusting portion are uniformly arranged inside the surface layer. 4. The valve body according to claim 2, wherein the surface layer is formed of rubber, the bite preventing portion is formed of resin, and the weight adjusting portion is formed of metal. 5. The valve element according to claim 1, wherein the valve element is a spherical ball valve element. 6. A valve seat is provided inside a body having a primary side opening and a secondary side opening, and a slope is provided for retracting a valve body from the valve seat to a body closer to the secondary side. In
A check valve, wherein the valve element according to any one of claims 1 to 5 is incorporated so as to be freely guided, and the valve element is separated from and brought into contact with the valve seat to open and close a flow path.