JPH036393B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vacuum breaker mainly for high-pressure fluid that reliably prevents backflow of secondary fluid.

[Conventional technology and its problems]

Generally, this type of vacuum breaker has a soft vent valve body interposed between the check valve body and the valve seat, and is configured to be able to close the vent hole penetrating the secondary side with the vent valve body. However, for example, when the valve is closed due to a water outage on the primary side, there may be sand or other foreign matter caught between the check valve body and the ventilation valve body, or the part cannot be sealed due to some other reason. In such cases, outside air is allowed to flow into the gap through the vent hole to prevent the fluid on the secondary side from flowing backward.

However, these conventional vacuum breakers have a complicated structure such as installing a valve stem or a conical coil spring in the center of the water passage, which inevitably leads to head loss due to increased flow resistance. The problem was pointed out.

Therefore, the applicant first installed a vent valve body above the vent hole, and made it possible to support the vent valve body by a check valve body fixed to a valve leg that slides along the peripheral wall of the passage. Although a vacuum breaker was devised (see Utility Model Application No. 60-202676 [Utility Model Application No. 62-110659]), there is no problem if the fluid pressure on the primary side of the vacuum breaker is low. In the case of high pressure of approximately 4 kg/cm2 ^{or more} , even if water flow is interrupted for some reason, the ventilation valve body is still loaded with considerable fluid pressure at the beginning, as shown in Figure 5. As shown, only the relatively soft inner circumferential edge portion (B) of the vent valve body (A) is pushed up by the check valve body (C), and the fluid remains in the middle portion (D) of the vent valve body (A), and the lower surface of the middle portion is pushed up by the vent hole hole. Since the valve remains blocked, the backflow prevention function of the vacuum breaker as described above is inhibited, and there remains a problem that remains to be resolved.

[Means for solving problems]

Therefore, the present invention creates a through hole with a diameter slightly smaller than the diameter of the valve seat between the valve seat built into the valve case and the check valve body equipped with the valve leg that slides along the inner wall of the passage. A radial groove facing the through hole is provided at the joint surface between the lower surface of the valve seat and the ventilation valve element, and an opening is provided at the bottom of the valve case by the ventilation valve element. The above-mentioned problems are solved by making it possible to close the vents.

[Effect]

The vacuum breaker of the present invention, when the valve is closed,
The presence of the groove reliably prevents fluid from remaining between the valve seat and the vent valve body.

〔Example〕

Hereinafter, the structure of the present invention will be described in more detail based on one embodiment shown in the drawings. Reference numeral 1 denotes a valve case having a small-diameter passage 2 connected to the lower part of the bottom, and numeral 3 denotes the upper end of the passage 2. 4 is a vent hole provided along the outer periphery of the vent valve seat, and 5 is a cylinder with a valve seat 5' in the center. This is a valve seat member having a shape, and a vent valve body 6, which will be described below, is clamped and fixed between it and the inner circumferential stepped portion 1' of the valve case 1.

The vent valve body 6 is made of an elastic material and has a through hole 6a in its center with a diameter slightly smaller than that of the valve seat 5', so that the fluid entering the upper surface of the valve body 6 under primary pressure is Therefore, the intermediate portion of the valve body is pushed downward and comes into contact with the vent valve seat 3, thereby blocking the vent port 4.

Reference numeral 7 denotes a plurality of concave grooves extending in the radial direction of the upper surface of the ventilation valve body 6, facing the through hole 6a, at equal intervals, and when the valve is closed, the grooves are connected to the lower surface of the valve seat 5'. This allows the fluid remaining between the vent valve bodies 6 to be discharged.

It should be noted that the same drainage effect can be obtained even if the groove 7 provided in the vent valve body 6 is instead provided through the lower surface of the valve seat 5'.

Furthermore, 8 is a check valve body that comes into contact with the lower surface of the inner circumferential edge 6b of the vent valve body 6, and at least three valve legs 9 fixed to the lower surface of the valve body are connected to the valve case passage 2.
The valve seat 9 is slidably inserted into the peripheral wall of the valve seat 9.
By interposing a spring 10 between the shoulder portion 9a and the spring receiver 10', the check valve body 8 can be moved up and down elastically.

In addition, especially the valve leg 9, as shown in FIG.
By integrally forming a stepped portion 9b directly below the check valve body 8 and providing a step G between the valve body and the shoulder portion 9a, the gap between the check valve body 8 and the compressed spring 11 is reduced. By enlarging the water passage p, water flow resistance can be further reduced. The same effect can be obtained even if the step G is changed to be inclined from the center to the shoulder 9a as shown by the dotted line in FIG.

Further, the vent valve body 6 has an inner peripheral edge 6b on its upper surface.
By providing at least one concentric blade-shaped, chevron-shaped, wave-shaped, etc. unevenness 6c that is inclined at a certain angle from The check valve body 8 is pressed against the lower surface of the valve seat 5' by the check valve element 8 pushed up by the spring 10 when closed, and by utilizing its restoring force, each valve can be opened more quickly. The vent hole 4 can be blocked off.

In the figure, reference numerals 11 and 11' indicate screw threads cut into the inner periphery of the valve seat member 5 and the outer periphery of the valve case passage 2, respectively, to connect them to, for example, a water pipe or a water supply hose.

Therefore, in the above-mentioned vacuum breaker, if you first attach the upper part to a water faucet and the lower part to a hose and run water through it, the vent valve body 6 is immediately pushed down by the water pressure under normal conditions. , its lower surface contacts the ventilation valve seat 3 and closes the ventilation port 4, and immediately after that, the water pressure pushes down the check valve body 8 against the elastic force of the spring 10, and the valve leg 9 is closed. The fact that water is passed through the hose to the target water storage tank, etc. is still the same as in previous vacuum breakers of this type.

However, if water flow is interrupted for some reason and the primary side becomes a negative pressure state, the pressure of the spring 10 pushes up the check valve body 8 and the ventilation valve body 6.
This part is closed to prevent the fluid on the secondary side from flowing backwards, but at this time, if foreign matter is interposed between the ventilation valve body 6 and the check valve body 8, the part may become blocked. If the airtightness of the valve body is impaired, the outside air continues to flow into the space between the valve bodies 6 and 8 through the vent 4, so that the fluid on the secondary side will not flow back.

If the pressure and water level of the fluid on the secondary side continue to rise, the vent port 4 acts as an overflow port to discharge the fluid to the outside, thereby reliably preventing backflow on the primary side.

〔Effect of the invention〕

As described above, according to the vacuum breaker of the present invention, even when used in a faucet with particularly high fluid pressure, the existence of the groove 7 prevents the valve from seating when the valve is closed, unlike conventional products. 5' and the vent valve body 6, and the vent port 4 is not blocked.
In addition to reliably preventing backflow of the secondary fluid, the structure is extremely simple with no valve stem or spring interposed in the center of the passage, so water flow resistance during water flow can be significantly reduced. , it produces many excellent roots and fruits that could not be expected from conventional vacuum breakers of this type.

[Brief explanation of drawings]

Fig. 1 is a front view in cross section of the left half of the vacuum breaker of the present invention, Fig. 2 is a perspective view of the vent valve body, Fig. 3 is a perspective view of the check valve body and the valve leg, and Fig. 4 is a perspective view of the vent valve body.
The figure is a partially cutaway front view showing another embodiment of the vent valve body, and FIG. 5 is a partially cutaway front view of a conventional product. In the figure, 1...valve case, 2...passage, 3...
Ventilation valve seat, 4...Vent hole, 5...Valve seat member, 6...
...Vent valve body, 7... Concave groove, 8... Check valve body, 9...
...valve leg.

Claims (1)

[Claims] 1. A check valve body 8 that includes a valve seat 5' built into the valve case 1 and a valve foot 9 that slides along the inner wall of the passage 2.
In between, there is a through hole 6a with a diameter slightly smaller than the diameter of the valve seat 5'.
A radial groove 7 facing the through hole 6a is provided in the joint surface between the lower surface of the valve seat 5' and the vent valve body 6, and a radial groove 7 facing the through hole 6a is provided. A vent hole 4 opened below the valve case 1 by 6.
A vacuum breaker characterized by being able to block and close. 2. The vacuum breaker according to claim 1, wherein the ventilation valve body 6 has at least one concentric groove 6c on its upper surface. 3. The vacuum breaker according to claim 1 or 2, wherein the groove 7 is provided through the ventilation valve body 6. 4. The vacuum breaker according to claim 1 or 2, wherein the groove 7 is provided through the lower surface of the valve seat 5'.