JPH09280473A - Water hammer preventing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability and to eliminate such problems as gas leakage or insufficient absorbing power as seen in a gas type or a spring type unit. SOLUTION: One opening end of a tube-like cylindrical body 2 whose both ends are opened, capable of being expanded by injection of fluid is airtightly attached to a hard base body 1 formed of a main passage 1 to be connected to a pipe through which fluid is allowed to flow and a following passage 12 to be communicated with and connected to the main passage 11 at a branch port 12A. The other opening end formed by folding up the cylindrical body 2 is airtightly attached to the hard base body 1, a sealed space is formed, an outflow port of the following passage 12 is opened into the sealed space, fluid is introduced into the sealed space, and therefore, shock to be transmitted through the pipe is absorbed and alleviated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water hammer preventer for absorbing and mitigating a liquid impact (water hammer) generated by a water hammer in a pipeline through which the liquid flows.

[0002]

2. Description of the Related Art In order to absorb a water hammer phenomenon of a liquid generated in a liquid conduit, it is known that a dedicated water hammer absorbing device or the like is attached to the conduit. That is, as such a water hammer absorbing device, for example, as shown in FIG. 14, a substantially tubular shape in which a passage hole 100A through which water passes is formed in the central portion and a hole 100B partially communicating with the passage hole 100A is formed in the peripheral wall. Casing 100
And a large number of through holes 101A are opened in the peripheral wall, and holes 100B
A pipe 101 fixed between the pipe and the passage hole 100A, and an expandable tube 102 provided so as to be attached to the outer peripheral side of the pipe 101, and connected to a water supply pipe near the faucet (not shown). The composition is known.

And, this water hammer absorbing device is
A predetermined gas is hermetically sealed inside the hole closed by the tube 102, and when a water hammer (water hammer) occurs, the tube is protected against the gas pressure in the hole 100B as shown in FIG. 102 is inflated to absorb the impact pressure.

[0004]

However, in such a gas-filled type water hammer absorption device,
There is a risk of gas leakage, and there is a problem in terms of durability. Further, a water hammer absorption device using a spring instead of the gas pressure has been proposed, but such a spring type device has a drawback that the structure is complicated. Further, this spring type also has a problem in durability.

In view of the above-mentioned circumstances, the present invention is a water hammer prevention device which is free from the problems such as gas leakage and insufficient absorption capacity, unlike the gas type and spring type, and which can also improve durability. It is intended to provide.

[0006]

That is, according to the invention described in claim 1, a main flow path connected to a pipe through which a fluid flows and a sub-flow path communicating with and connected to the main flow path through a branch port are formed. To the rigid base, one opening end of the tubular body with both ends that can be expanded by injecting fluid is airtightly attached, and the other opening end of the folded back body is airtightly attached to the hard base and sealed. A space is formed, an outlet of the sub-flow path is opened in the sealed space, and a fluid is introduced into the sealed space to absorb and mitigate the shock transmitted through the pipe.

Further, in the invention according to the second aspect, a throttle is provided in the main flow passage which faces the branch port of the sub flow passage.

According to the third aspect of the present invention, the main flow passage portion facing the branch opening of the sub flow passage constitutes a Venturi tube.

[0009]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic sectional view showing a water hammer prevention device according to a first embodiment of the present invention. This water hammer prevention device is connected to a water supply pipe near a faucet (not shown), and has a hard base body 1 that is in communication / connection (for example, screw connection) with the water supply pipe, and a hard base body. 1 and an inflatable tube-shaped tubular body 2 that is provided around the outer peripheral surface.

The hard substrate 1 is made of an appropriate hard material and is formed into a hollow, substantially cylindrical shape. Inside, a main channel 11 communicating with the channel of the water supply pipe and a secondary channel communicating with the main channel 11 through a branch port 12A. The flow path 12 is formed. That is, the sub-flow passage 12 is formed in the thickness direction of the wall surface of the cylindrical hard substrate 1 (or in a direction having an appropriate inclination angle) and penetrates the peripheral wall. It should be noted that the sub-flow passage 12 has a significantly narrower opening cross-sectional area than the main flow passage 11,
It is configured so that it can function as a Venturi tube.

The tubular body 2 is made of an elastic material such as elastic rubber and formed into a shape as shown in FIG. That is, the tubular body 2 is formed of an elastic tube and is formed by folding one of the open ends into the inner side (or the outer side). The tubular body 2 is positioned such that the annular opening 2A faces the outlet 12B (the position opposite to the branch 12A) of the secondary base 12 on the side of the hard substrate 1, that is, this flow. Both ends are attached in a watertight manner by caulking rings 21 and 22 so as to cover the outlet 12B.

Therefore, according to the first embodiment, in the normal water supply state with the faucet opened, as shown in FIG.
Since water flows through the inside of the cylinder 1 at a high speed, a negative pressure does not act on the inside of the cylinder 2 to expand it.

Also, when the faucet is closed, the flow of water toward the faucet is stopped, so that the negative pressure (suction force) for contracting the tubular body 2 does not act because the flow velocity decreases at the branch port 12A. As a result, water flows into the inside of the cylindrical body 2 from the sub-flow passage 12, and the cylindrical body 2 expands as shown in FIG. 4, so that a water hammer (water hammer) which is conventionally applied to the faucet can be suppressed. Becomes

In this embodiment, the expanding operation of the cylindrical body 2 is performed freely. For example, as shown in FIG. 5, the cylindrical body 2 has a hard cylindrical shape with an appropriate inner diameter outside the cylindrical body 2. The cover 3 may be inserted to limit the maximum expansion radius to a constant value.

Therefore, according to this embodiment, when the cylindrical body 2 having a constant area is attached to the hard substrate 1, spherical expansion is performed unlike conventional planar expansion, so that the cylinder corresponding to the attachment area is expanded. The expansion capacity of the body 2 can be greatly increased, the interference effect of the water hammer phenomenon (water hammer) can be increased correspondingly, and a compact water hammer preventer can be provided.

Next, a second embodiment of the present invention will be described. In this embodiment, the same parts as those in the first embodiment are designated by the same reference numerals to avoid redundant description. FIG.
The water hammer prevention device shown in (4) is connected to a water supply pipe near the faucet (not shown) as in the previous embodiment. Can be applied to other gases, etc.),
A hard base body 1 that communicates with and is connected to the water supply pipe (for example, is similarly connected by a screw connection or the like);
The cylindrical body 2 is provided around the protruding portion 4.

The protrusion 4 is formed in a substantially cylindrical shape,
A sub-flow passage 41 communicating with the main flow passage 11 of the hard substrate 1 is formed inside this. The sub-channel 41 is a branch port 41.
The flow path communicates with the main flow path 11 via A, and the 90-degree flow path is bent along the way and is branched into a plurality of parts, and finally connected to the outlet 41B opened on the outer peripheral surface of the protrusion 4. The sub flow passage 41 here also has a significantly narrower opening cross-sectional area than the main flow passage 11.

The cylindrical body 2 has a shape similar to that shown in FIG. 2, and like the previous embodiment, it is suitable to cover the outlet 41B of the sub-flow passage 41, and both end sides are added. It is attached in a watertight state by tightening rings 21 and 22.

Also in this embodiment, a water hammer (water hammer) is suppressed by the same action as that of the first embodiment, that is, the expansion action of the cylindrical body 2, but the aperture 1A as shown in FIG. 7 or FIG. Alternatively, by forming 1B in the vicinity of the branch port 41A of the main flow path 11 of the hard base body 1 to form a Venturi tube, it is possible to further enhance the water hammer (water hammer) absorption effect.

As in the first embodiment, the cover 3'as shown in FIG. 9 may be covered. Also in this case, the venturi pipe is configured by narrowing the main passage 11 that faces the branch port 41A of the sub passage 41 of the protruding portion 4 to form a throttle. In addition to this, as shown in FIG. 10, the protrusion 4 and the hard substrate 1 may be screwed together.

Further, as shown in FIGS. 11 and 12, the sub-flow paths 51 and 61 having the passage cross-sectional areas narrowed in consideration of the flow of water hydrodynamically are provided in the predetermined directions of the protrusions 5 and 6. It may be formed to have the same function as that of the Venturi tube. That is, in the configuration shown in FIG. 11, the sub-flow path 51 tilted at an appropriate angle (excluding a right angle) in the direction opposite to the water flow direction (flow from the left side to the right side as shown in the drawing) is provided in the protruding portion 51. It may be provided so as to generate a sealing effect similar to the Venturi effect.

Therefore, for example, when a faucet (not shown) in FIG. 11 is closed, the flow of water in the direction of the arrow toward the faucet in the main flow path 11 is dammed and a water hammer (water hammer) is about to occur. The water hammer can be suppressed by the expansion action of the tubular body 2 because it can be guided into the sub-flow passage 51 and flow into the tubular body 2. Further, in the configuration shown in FIG. 12, since the sub-channel 61 is formed at least at the branch port 61A of the protrusion 6 at an appropriate angle that is not a right angle to the direction opposite to the normal water flow,
A sealing effect can be generated as in the case of FIG. 11, and a water hammer (water hammer) is suppressed by the expansion action of the cylindrical body 2.

In these embodiments, it is general that the tube 20 as shown in FIG. 13 is folded back to form the cylindrical body 2, but the tube 20 used here has a peripheral wall surface By embedding an appropriate filamentous member 20A in the above, the amount of expansion may be appropriately suppressed and the destruction during expansion may be prevented.

[0024]

As described above, according to the water hammer prevention device of the present invention, no gas, spring or the like is used, that is, an elastic tube is used, and it is easily formed by, for example, folding it back. Since the water hammer is effectively suppressed by the cylinder,
There is no risk of gas leakage or insufficient absorption, and durability is greatly improved. Further, according to the present invention, since the structure is simple and simple, the assembling workability is good, the device can be downsized, and the manufacturing at low cost can be realized.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a vibration damping device according to a first embodiment of the present invention.

FIG. 2 is a cutaway perspective view showing a tubular body of the apparatus.

FIG. 3 is an explanatory view showing the operation of the device.

FIG. 4 is an explanatory diagram showing an operation of the apparatus.

FIG. 5 is a schematic cross-sectional view showing a modified example.

FIG. 6 is a schematic sectional view showing a vibration damping device according to a second embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view showing a modified example of the same device.

FIG. 8 is a schematic sectional view showing still another modified example.

FIG. 9 is a schematic sectional view showing still another modified example.

FIG. 10 is a schematic sectional view showing still another modified example.

FIG. 11 is a schematic sectional view showing still another modified example.

FIG. 12 is a schematic sectional view showing still another modified example.

FIG. 13 is a schematic perspective view of a tube used in the cylinder body of the present invention.

FIG. 14 is a schematic cross-sectional view showing a conventional example.

FIG. 15 is a schematic sectional view showing the operation of the conventional example.

[Explanation of symbols]

 1 Hard Base 1 11 Main Flow Path 12, 41, 51, 61 Sub Flow Path 12A, 41A Branch Port 12B, 41B Outlet Port 2 Cylinder 2A Opening 4, 5, 6 Projection

Claims (3)

[Claims] 1. A tube having openings at both ends which is expandable by injecting a fluid into a hard substrate having a main channel connected to a pipe through which a fluid flows and a secondary channel communicating with and connected to the main channel at a branch port. One open end of the cylindrical body is airtightly attached, and the other open end of the folded back cylinder is airtightly attached to the hard base body to form a sealed space. A water hammer preventer characterized in that an outlet is opened and a fluid is introduced into the sealed space to absorb and mitigate an impact transmitted through the pipe. 2. The water hammer preventer according to claim 1, wherein a throttle is provided in the main flow passage facing the branch opening of the sub flow passage. 3. The water hammer preventer according to claim 1, wherein the main flow passage portion facing the branch opening of the sub flow passage constitutes a Venturi tube.