JPH08303678A - Water hammer preventing device - Google Patents

Abstract

PURPOSE: To provide a water hammer preventing device in which the basic performance for decreasing the peak value of shock is satisfied, watertightness to high water pressure and durability for maintaining the specified performance are provided. CONSTITUTION: An extending and contracting protective film 21 composed of a protective film part 21A extending in the direction approximately perpendicular to the water hammering direction, an extending and contracting part 21B extending in the approximately water hammering direction from the periphery of the protective film 21A, and a flange part 21C extending from the periphery of the extending and contracting part 21B, and made of a rubber elastic body is arranged on the front surface of a cushioning material 19 formed of syntactic foam formed by adding fine hollow bodies provided with elastic sheaths to gel or rubber as the base material. Moreover, an orifice 13 is arranged in such a position as to face the extending and contracting protective film 21. Since the cushioning material 19 is not bored caused by water hammer, and since tensile force to be generated by water hammering is absorbed by the extending and contracting part 21B, the basic performance for decreasing the specified peak value of shock can be maintained over a long period.

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 protecting pipes, faucet devices, hydraulic machines, etc. from so-called water hammer action, and particularly, to satisfy the basic performance of reducing the peak value of impact, It also relates to water-tightness and durability.

[0002]

2. Description of the Related Art For example, in a water supply pipe, when a power failure suddenly occurs during operation of a water supply pump, an impeller in the pump or the entire pipe is suddenly overloaded. This phenomenon is known as a water hammer effect (water hammer) due to the inertial force of water. Recently, this water hammer effect has been frequently experienced even in general households because a single lever type faucet that can open and close the valve with one touch by operating one lever up and down has become widespread. Also, regarding the water supply pipes for fully automatic washing machines and flush toilets,
Similarly, the water hammer is generated due to the sudden closing of the valve. Due to the recent rise in environmental conservation, apartment houses (apartments,
In a condominium, etc., the sound of water hammer generated from a neighboring house is becoming a social problem that develops into a noise problem. Therefore, a water hammer preventer that combines a bellows, a spring, a cushioning material, and the like, and a small and effective water hammer prevention device have been proposed. With this water hammer preventer,
A large peak of impact value due to water hammer when the valve is closed can be suppressed.

[0003]

In the above-mentioned prior art, for example, a water hammer preventer in which a bellows, a spring, a cushion material and the like are combined not only has a complicated structure, but also has a water hammer suppressing action depending on a setting condition by a composite member. , The setting balance is liable to be lost, and the performance is significantly reduced outside the recommended water pressure. In addition, the built-in composite material becomes large, it is not suitable for installation in general households, and there is a restriction in the installation direction (top and bottom etc.) due to air accumulation,
In addition, since the cost becomes high, there is a problem in that it is being braked for its widespread use in households.

Further, it has been known to use silicone rubber or the like as a cushioning material in place of the bellows and the spring (Japanese Patent Laid-Open No. 3-186691). However, it has been found that the impact peak value cannot be reduced as desired only by using the above-mentioned cushioning material. Then, various tests were conducted to solve such a problem. As a result, a specific syntactic foam was used as a cushioning material, and an orifice was arranged on the front surface to reduce the peak value of impact. To prevent the initial performance from being maintained because needle-shaped holes were made in the syntactic foam in a short time due to the hydraulic flow injected from the orifice, a stretchable protective film was formed on the surface of the cushioning material. It is thought that it will respond by doing.

However, in this case, although the basic performance of temporarily reducing the peak value of the impact can be satisfied, the watertightness withstanding the high water pressure required for the water hammer preventer and the basic performance for a long period of time are required. It cannot be said that the durability to maintain is sufficient, and the development of products satisfying these conditions has been desired. Also, depending on the applied flow rate, the basic performance may not be exhibited especially at high flow rates,
It has been desired to develop a product capable of exhibiting the basic performance of reducing the shock peak value without adjustment in a wide range from a small flow rate to a large flow rate.

The present invention has been made on the basis of the above points, and an object thereof is to satisfy the basic performance of reducing the peak value of impact, and to achieve the watertightness withstanding high water pressure and the predetermined performance for a long time. It is to provide a water hammer preventer having durability to be maintained. Another object of the present invention is to provide a product capable of exhibiting the basic performance of reducing the peak value of impact without adjusting from a small flow rate to a large flow rate.

[0007]

In order to achieve the above object, a water hammer preventer according to claim 1 of the present invention is a main body case having a connecting tool to a water pipe or the like, and a gel disposed in the main body case. Alternatively, a cushioning material made of syntactic foam formed by adding a micro hollow body having a rubber base material and an elastic outer shell to the base material and a cushioning material arranged on the surface of the cushioning material and substantially orthogonal to the water hammer action direction. Direction of the protective film portion, a stretchable portion extending from the periphery of the protective film portion in the water hammer action direction, and a flange portion extending from the periphery of the stretchable portion. A protective film and an orifice arranged at a position facing the stretchable protective film of the connector.

A water hammer preventer according to a second aspect of the present invention includes a main body case having a connecting tool for a water pipe or the like, and a gel or rubber base material disposed in the main body case and having an elastic outer shell. Cushioning material formed of a syntactic foam formed by adding a micro hollow body having: a protective film portion disposed on the surface of the cushioning material and extending in a direction substantially orthogonal to the water hammer action direction; Elastic protective film formed of a rubber-like elastic body composed of an elastic part extending from the periphery of the elastic member substantially in the direction of water hammer and a flange extending from the periphery of the elastic part, and the elastic protective film of the connector. And a perforated body having a small hole arranged close to the surface of the stretchable protective film and having a small hole diameter smaller than the hole diameter of the orifice. Features It is.

[0009]

When the water hammer preventer according to claim 1 of the present invention is installed on the way of piping of a water pipe, the water hammer energy generated by the abrupt valve closing operation in the water pipe is first attenuated by the inlet orifice, and then the main body. It propagates in the case and is attenuated by the cushioning material covered with the stretchable protective film. As described above, the water hammer energy undergoes a two-step damping action. The damping effect of the inlet orifice is
It is not only achieved by the presence of the inlet orifice, but it is the damping effect that is first exhibited by arranging the above-mentioned cushioning material on the rear surface, and if the cushioning material is made of a solid body that does not contain the micro hollow body, for example. However, even if the orifice is arranged facing this, sufficient damping action cannot be obtained.

Further, the above-mentioned cushioning material protects the syntactic foam formed by adding a micro hollow body having a gel or rubber as a base material and having an elastic outer shell to the stretchable protective film. , There is no hole due to water hammer, and the stretchable protective film is made of a rubber-like elastic body,
In addition, since the expansion and contraction part that expands and contracts in the water hammer action direction is formed and the tensile force due to the water hammer effect is absorbed by the expansion and contraction part, the main body case can be strongly crimped at the flange part, and watertightness that can withstand high pressure is obtained. In addition, it is possible to maintain the basic performance of preventing the stretchable protective film from being damaged and reducing the peak value of a predetermined impact for a long period of time. Further, since it is processed into a small diameter column, the water hammer preventer can be compactly constructed.

According to a second aspect of the water hammer preventer of the present invention, the stretchable protective film is provided with the cushioning material made of the syntactic foam, the stretchable protective film and the orifice, and facing the orifice of the connector. By interposing a perforated body having a small hole close to the surface, and the hole diameter of the small hole of the perforated body is set smaller than the orifice hole diameter, the water hammer energy is primarily attenuated at the orifice,
After being secondarily damped by the small holes of the perforated body, it is finally damped by the cushioning material, and undergoes a three-step damping action, which not only exerts the damping effect of suppressing the peak value of the water hammer to a low level. , The effect of reducing the peak value of impact is exhibited in a wide range from a small flow rate to a large flow rate.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a partially longitudinal front view showing the structure of the water hammer preventer 10. The water hammer preventer 10 according to the present invention is installed by screwing a screw portion 11A provided on a connector 11 to a branch connecting pipe 2 provided on the way of a water pipe 1. The connection tool 11 has an orifice 13 attached to its inlet and a flange portion 11B formed above. A cylindrical body case (diameter of about 30 mm, length of about 30 mm) having a downward opening is capped on the flange portion 11B.
A cushioning material 19 made of syntactic foam formed by adding a micro hollow body 17A having an elastic outer shell to a base material 17 made of gel or rubber is attached (filled).

An elastic protective film 21 is closely attached to the surface of the cushioning material 19 (opening side of the main body case 15), and the main body case 15 is sandwiched with the flange portion 21C of the elastic protective film 21. The outer peripheral edge 15A of the connection tool 11
It is integrated with the flange portion 11B by crimping.

Next, the physical properties of the syntactic foam forming the cushioning material 19 will be described in detail. The syntactic foam referred to in the present application uses a gel or rubber as the base material 1.
Micro hollow body 17A having an elastic outer shell
And is also called a synthetic foam, and a silicon syntactic foam is preferably used. In this case, the silicone gel or silicone rubber is JIS K 22
Penetration 200 by 07 (50g load) -JIS K
A rubber having a rubber hardness of 6301 in the range of about 50 can be applied, and the micro hollow body is a micro hollow sphere of several tens μm to 1,000 μm, and this is added by about 1 to 6%.

A suitable silicone rubber is CX52-282 manufactured by Toray Dow Corning Silicone Co., Ltd.
There is. This is a fast curing product that begins to cure in a few minutes and has an Asker C hardness of about 55. Incidentally, the Asker C hardness is measured by SRIS 0101 (Japan Rubber Association standard) or JISS 6050 which is specified as suitable for measuring rubber, foamed elastomer, sponge, etc. which is softer than the rubber hardness according to JIS K 6301. is there. Examples of the silicone gel include CY52-276 manufactured by Toray Dow Corning Silicone Co., Ltd. Of course, even if these silicone gels or silicone rubbers are not used, they have the above-mentioned hardness, excellent temperature characteristics, do not worry about elution, do not deteriorate, and have basic properties such as durability. If applicable, it can be applied.

The micro hollow body added is a micro hollow body having a shell made of an elastic synthetic resin capable of self-elastic deformation and having a diameter of several tens of μm to 1,000 μm. Examples thereof include Expancel (registered trademark) manufactured by Nippon Philite Co., Ltd. and Matsumoto Microsphere manufactured by Matsumoto Yushi-Seiyaku Co., Ltd. In this embodiment, Matsumoto Microsphere 80EDL (diameter 200 μm) is used.

Incidentally, these micro hollow bodies generally have a size of 5 μm to 1 μm.
Those having a diameter of about 00 μm are commercially available as a general grade, but those having an improvement of about 200 μm to 1000 μm are preferable. Note that theoretically 100
It is expected that the one expanded to about 0 μm will have a better buffering effect, but it is actually 1000 μm.
Since it is necessary to make the shell thickness thicker in order to expand to a certain degree, on the contrary, the result of 200 μm to 300 μm having an excellent buffering effect has been obtained.

A stretchable protective film 21 is closely attached to the surface of the cushioning material 19 (on the opening side of the main body case 15). The stretchable protective film 21 is formed of a rubber-like elastic material, and is made of synthetic rubber such as silicone rubber or EPDM (isoprene rubber), natural rubber, or the like, in consideration of durability and elution property to water. Is selected. In this embodiment, a millable silicone rubber (TSE260-3U made by Toshiba Silicone) is used. This product is excellent in heat resistance, high tear resistance and safety,
It can also be used for instant water heaters, water heaters, etc.

With respect to the shape of the stretchable protective film 21, the protective film portion 21A extending on the surface of the cushioning material 19 in a direction substantially orthogonal to the water hammer action direction, and substantially from the periphery of the protective film portion 21A. Expansion / contraction part 21B extended in the water hammer action direction,
Flange portion 21 extended from the periphery of the stretchable portion 21B
It is formed from C. Also, the plate thickness of this thing absorbs water hammer energy and is dented and displaced together with the cushioning material 19, so that when the water hammer energy disappears, the restoring force of the cushioning material 19 and its own restoring force together return. The condition is set to about 5 mm.

Here, the stretchable portion 29B of the stretchable protective film 21.
The parts other than are bonded to the cushioning material 19 and the main body case 15. That is, since a water hammer pressure acts between the protective film portion 21A and the cushioning material 19, a negative pressure is momentarily generated, so that the protective film portion 21A and the cushioning material 19 are integrally laminated by an adhesive so as not to separate. Further, the flange portion 21C and the main body case 15 and the flange portion 21C and the flange portion 11B of the connector 11 are bonded with an adhesive to prevent water from entering the cushioning material 19 side. There is. It should be noted that these parts do not necessarily have to be adhered to each other, and by firmly crimping the main body case 15 and the connector 11, it is possible to maintain predetermined basic performance, durability, and watertightness.

The operation will be described based on the above configuration. First, the inlet orifice 13 of the water hammer preventer 10 installed on the way of the water pipe 1 attenuates the water hammer energy generated by the abrupt valve closing operation in the water pipe and propagates it into the main body case 15. The water hammer energy is attenuated by the buffer material 19 covered with the stretchable protective film 21. As described above, the water hammer energy undergoes a two-stage damping action, and is finally damped by the cushioning material 19. The damping action by the inlet orifice 13 is not exerted only by the presence of the inlet orifice 13,
This is the damping effect that is first exhibited by arranging the cushioning material 19 on the rear surface. If the cushioning material 19 is made of, for example, a solid body that does not contain the minute hollow body 17A, the orifice 13 is arranged facing it. It has been experimentally confirmed that even if this is done, a sufficient damping effect cannot be obtained.

Since the cushioning material 19 made of syntactic foam is covered with the stretchable protective film 21, it does not cause perforation or the like and exhibits its durability. In addition, the stretchable protective film 21 is formed with a stretchable portion 21B extending substantially in the water hammer action direction between the protective film portion 21A and the flange portion 21C, and the stretching force of the water hammer action causes the stretchable portion 21B to stretch. Be absorbed by Therefore, the stretchable protective film 2
Main body case 1 with the flange portion 21C of No. 1 sandwiched
Since the outer peripheral edge 15A of 5 can be strongly caulked to the flange portion 11B of the connector 11, a high degree of watertightness can be obtained and durability can be exhibited. In addition, the portion of the stretchable protective film 21 excluding the stretchable portion 21B is the cushioning material 19 and the main body case 15.
Since it is adhered to the cushioning material 19 and the stretchable protective film 21.
Are integrated with each other, and water does not enter the cushioning material 19 side.

As described above, according to this embodiment, the following effects can be obtained. First, according to the water hammer preventer of the present embodiment, the water hammer energy is attenuated at the inlet orifice 13 of the connector 11 and is damped by the cushioning material 19 covered with the stretchable protective film 21. It has a dampening effect that damps impact energy and keeps the peak value of water hammer energy low. Further, since the cushioning member 19 is processed into a small-diameter columnar shape, even if the water hammer preventer is constructed compactly, the same water hammer damping action as that of the conventional bellows type is exhibited. Further, in the conventional bellows type, there was a restriction in the mounting direction (top and bottom, etc.) due to air accumulation, but in this embodiment there is no such restriction, and it can be operated in any mounting direction. Further, the buffer material 19 is made of gel or rubber as a base material, and a syntactic foam formed by adding a micro hollow body having an elastic outer shell to the base material is covered with a stretchable protective film 21. There is no perforation, and its durability is guaranteed.

Further, the stretchable protective film 21 is formed of a rubber-like elastic body, and the stretchable portion 21B which stretches and shrinks in the water hammer action direction is formed. The stretchable portion 21B absorbs the tensile force due to the water hammer action. With this configuration, it is possible to strongly crimp the connector 11 and the main body case 15 at the flange portion 21C, obtain watertightness that can withstand high pressure, and effectively prevent damage to the stretchable protective film 21. ,
It is possible to maintain the basic performance of reducing the peak value of a given impact over a long period of time. The portion of the stretchable protective film 21 excluding the stretchable portion 29B is the cushioning material 19, the main body case 15
Since it is adhered to the cushioning material 19 and the stretchable protective film 21.
It is possible to prevent the peeling of the water and the water and prevent the water from entering the buffer material 19 side.

Next, a second embodiment of the present invention will be described with reference to FIGS. This embodiment is different from the first embodiment in that the cushioning material 19 facing the orifice 13 of the connector 11 is provided.
A perforated plate body 27 having a small hole 27A is provided close to the surface of the stretchable protective film 21. The hole diameter (a) of this small hole 27A is set smaller than the hole diameter (b) of the orifice 13.

Here, the stretchable portion 29B of the stretchable protective film 21.
Except for the parts, cushioning material 19, main body case 15, perforated plate 27
It is glued with. That is, since a water hammer pressure acts between the protective film portion 21A and the cushioning material 19, a negative pressure is momentarily generated, so that the protective film portion 21A and the cushioning material 19 are integrally laminated by an adhesive so as not to separate. Further, the flange portion 21C and the main body case 15
And the flange portion 21C and the perforated plate body 27 are bonded with an adhesive in order to prevent water from entering the cushioning material 19 side. It should be noted that these respective parts do not necessarily have to be adhered, and the predetermined basic performance, durability, and watertightness can be maintained by strongly crimping the main body case 15 and the connector 11. The configuration and function of other parts are the same as those in the first embodiment.
It is the same as the embodiment, and the same reference numerals are given to omit the description.

In the case of the second embodiment, the orifice 1
The water hammer energy is first attenuated at 3, and the plate body 2
The secondary damping is performed in the small holes 27A of No. 7 and finally the cushioning material 19
The water hammer energy is damped in three steps, and there is a dampening effect that keeps the peak value of the water hammer energy low. Also, due to the two-stage throttling effect and the damping effect of the cushioning material, there is an effect that it can be applied in a wide range from a small flow rate to a large flow rate without adjustment.

Next, the water hammer preventer of each embodiment of the present invention was connected to a water hammer prevention effect test device 40 as shown in FIG. 4 to test the water hammer prevention effect. Explaining the above apparatus, the water supply system 41 is composed of a pipe 45 supplied with water from a pressure pump 43. The pipe 45 has a pressure control valve 47, a check valve 48, a quick closing valve 49 and a flow rate control valve 51. Water hammer preventer 10 of the present invention
Is the branch pipe 5 between the check valve 48 and the quick closing valve 49 of the pipe 45.
3 is screwed on. Further, a branch pipe 55 is connected to the upstream side of the water hammer preventer 10, and a pressure sensor 57 and a FET analyzer 59 connected to the pressure sensor 57 are provided here.

Regarding the water hammer prevention effect, the peak hammering effect showing how the peak value of the water hammer is suppressed due to the water hammer phenomenon and the vibration damping (vibration) after the water hammer phenomenon occurs. Since it can be expressed as a damping characteristic indicating convergence, a test was performed on both of them. As for durability, the above test should be conducted at specified intervals.
The change was confirmed by repeating the operation up to 100,000 times. The results are shown below.

(Test Example) The reference water pressure is set to 2 by the pressure control valve 47.
and kgf / cm ^2, it was tested by installing a water hammer arrestor 10 in a position such as water hammer pressure force of about 20 kgf / cm ² in the case using no water hammer arrestor. The peak value suppressing effect in this test example was as follows. (1) FIG. 5 shows water hammer pressure characteristics without a water hammer protector, with a peak value of 20 kgf / cm ²
The vibration after the peak has not diminished and has been prolonged. (2) FIG. 6 shows the water hammer pressure characteristic of the 10th time after the start of the test of the water hammer preventer 10 of the second embodiment of the present invention having the stretchable protective film 21 and the perforated plate body 27, and the peak value is 9.
At 2 kgf / cm ² , the peak value is suppressed compared to the case without a water hammer protector, and a damping effect after the peak is also observed. (3) FIG. 7 shows the water hammer pressure characteristic of the 10,000th time as above, with a peak value of 8.9 kgf / cm ² and a damping action after the peak. (4) FIG. 8 shows the water hammer pressure characteristic of the 20,000th time, and the peak value is 8.8 kgf / cm ² and the damping action after the peak is also observed. (5) FIG. 9 shows the water hammer pressure characteristic for the 50,000th time, same as above, with a peak value of 9.1 kgf / cm ² and a damping effect after the peak. (6) FIG. 10 shows the water hammer pressure characteristic of the 70,000th time,
The peak value is 9.1 kgf / cm ² , and the post-peak damping effect is also observed. (7) FIG. 11 shows the water hammer pressure characteristic at the 100,000th time, same as above, with a peak value of 9.1 kgf / cm ² and a damping effect after the peak.

From the above test results, the water hammer preventer 10 of the present invention can exhibit the basic performance of suppressing the peak value of the water hammer, and the durability also has the basic performance during the test of 100,000 times. Has been confirmed to have sufficient durability. Regarding the watertightness, when the presence of water leak was tested by pressurizing with a water pressure of 100 kgf / cm ² together with the above test results, no water leak was found.
It has been confirmed that there is sufficient water tightness.

Next, FIG. 12 shows the test apparatus 40.
The water pressure is 1.5 kgf / cm²To 6 kgf / cm²
Up to 1.5 kgf / cm²Waterhan
No water hammer preventer, water hammer preventer 10 of the first embodiment
(Without eyelet body), water hammer preventer 1 of the second embodiment
Fold the water hammer peak value for each sample of 0 (with plate)
It is shown by a line graph. From this test result, low
1.5kgf / cm of pressure ²(Small flow rate) to high pressure 6 kg
f / cm²At each water pressure up to (large flow rate),
The water hammer peak value decreases when equipped with a Tahammer protector.
Can be confirmed. In addition, the second equipped with a plate 27
The water hammer preventer 10 of the embodiment has a higher water hammer peak value.
Can be lowered, but the first without the perforated plate body 27
Also in the case of the example, the peak value damping effect may be exhibited.
I can confirm.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that design changes in details can be freely made within the scope of the invention. For example, the shape change of the connector 11 and the main body case 15 and the attachment method of the orifice 13 and the perforated plate body 27 are not limited to those shown in the drawings. For example, as shown in FIGS. The watertightness can be improved by forming the portion 50A and the flange portion 51A of the connection tool 51 from stainless steel and seam welding the connection portions of both. Further, as shown by the broken line in FIG. 14, the flange peripheral edge 53C of the expansion / contraction wire protective film 53 is formed by bulging in an O-ring shape, and is compressed during seam welding or caulking as in the above-described embodiment. Thereby, the water tightness can be further improved. Although the water hammer preventer of the present invention has been applied to water, it can be applied to liquids other than water.

[0034]

As described in detail above, according to the water hammer preventer of the first aspect of the present invention, the water hammer energy is attenuated at the inlet orifice of the connecting tool, and the water hammer energy is damped by the cushioning material coated with the elastic protective film. Therefore, the water hammer energy is damped in two steps, and there is a dampening effect of keeping the peak value of the water hammer energy low. Further, since the cushioning material is processed into a small-diameter columnar shape, even if the water hammer preventer is compactly constructed, a water hammer damping action equivalent to that of the conventional bellows type is exhibited. Further, in the conventional bellows type, there was a restriction in the mounting direction (top and bottom etc.) due to the air accumulation, but in the present invention there is no such restriction and it can be operated in any mounting direction. The above-mentioned cushioning material is made of gel or rubber as a base material, and a syntactic foam formed by adding a micro hollow body having an elastic outer shell to the base material is covered with a stretchable protective film. And its durability is guaranteed.

Further, the stretchable protective film is formed of a rubber-like elastic body, and further, a stretchable portion that stretches in the water hammer action direction is formed, and the stretching force is absorbed by the stretchable portion. Therefore, it is possible to strongly crimp the connection tool and the main body case at the flange portion, obtain water-tightness that can withstand high pressure, effectively prevent damage to the stretchable protective film, and prevent a predetermined impact over a long period of time. The basic performance of reducing the peak value can be maintained.

According to the water hammer preventer of the second aspect of the present invention, in addition to the effect exhibited by the first aspect, the water hammer energy is primarily attenuated by the orifice, and the small holes of the perforated body prevent the water hammer energy from being attenuated. The water hammer energy is attenuated in three stages because it is finally attenuated by the cushioning material after the next attenuation.
There is a damping effect that keeps the peak value of water hammer energy low. Further, due to the two-stage throttling effect and the damping effect of the cushioning material, there is an effect that a water hammer preventer which can be applied in a wide range from a small flow rate to a large flow rate without adjustment is obtained.

[Brief description of drawings]

FIG. 1 is a view showing a first embodiment of the present invention and is a partially longitudinal front view of a water hammer preventer.

FIG. 2 is a view showing a second embodiment of the present invention and is a partially cutaway perspective view of a water hammer preventer.

FIG. 3 is a view showing a second embodiment of the present invention and is a partially longitudinal front view of a water hammer preventer.

FIG. 4 is a front view of a water hammer prevention effect testing device.

FIG. 5 is a characteristic diagram showing a water hammer pressure change when there is no water hammer preventer.

FIG. 6 is a characteristic diagram showing changes in water hammer pressure of the water hammer preventer of the present invention.

FIG. 7 is a characteristic diagram showing changes in water hammer pressure of the water hammer preventer of the present invention.

FIG. 8 is a characteristic diagram showing changes in water hammer pressure of the water hammer preventer of the present invention.

FIG. 9 is a characteristic diagram showing changes in water hammer pressure of the water hammer preventer of the present invention.

FIG. 10 is a characteristic diagram showing a water hammer pressure change of the water hammer preventer of the present invention.

FIG. 11 is a characteristic diagram showing changes in water hammer pressure of the water hammer preventer of the present invention.

FIG. 12 is a characteristic diagram showing a water hammer pressure change at each normal water pressure of the water hammer preventer of the present invention.

FIG. 13 is a view showing another embodiment of the present invention and is a sectional view of a water hammer preventer.

FIG. 14 is a view showing another embodiment of the present invention and is an exploded sectional view of a water hammer preventer.

[Explanation of symbols]

 1 Water Pipe 10 Water Hammer Preventer 11 Connector 11A Screw Part 13 Orifice 15 Main Body Case 17 Base Material 17A Micro Hollow Body 19 Buffer Material 21 Stretchable Protective Film 21A Protective Film Part 21B Extendable Part 21C Flange Part 27 Eye Plate 27A Small Hole 40 Water hammer prevention effect test device

Claims (2)

[Claims] 1. A main body case having a connector for connecting to a water pipe or the like, and a micro hollow body having a gel or rubber as a base material and having an elastic outer shell added to the main body case. Cushioning material made of syntactic foam,
A protective film portion which is disposed on the surface of the cushioning material and extends in a direction substantially orthogonal to the water hammer action direction, and a stretchable portion which extends substantially in the water hammer action direction from the periphery of the protective film portion and the periphery of the stretchable portion. A water hammer including an elastic protective film formed of a rubber-like elastic body and including an extended flange portion, and an orifice arranged at a position facing the elastic protective film of the connector. Preventer. 2. A main body case having a connector for connecting to a water pipe or the like, and a micro hollow body which is disposed in the main body case and has a gel or rubber as a base material and which has an elastic outer shell. Cushioning material made of syntactic foam,
A protective film portion which is disposed on the surface of the cushioning material and extends in a direction substantially orthogonal to the water hammer action direction, and a stretchable portion which extends substantially in the water hammer action direction from the periphery of the protective film portion and the periphery of the stretchable portion. A stretchable protective film formed of a rubber-like elastic body made of an extended flange portion, an orifice arranged at a position facing the stretchable protective film of the connector, and a surface close to the stretchable protective film. And a perforated body having a small hole whose diameter is set smaller than the diameter of the orifice, the water hammer preventer.