JP3020335U - Water hammer preventer - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a water hammer preventer capable of reducing the peak value of impact when applied to a steel pipe and preventing noise when applied to a resin pipe in a sheath pipe header construction method. A main body case (15) provided with a connecting tool (11) for connecting to a pipe or the like having a first orifice (13) having a sufficiently large hole diameter at an inlet and a space portion (14) having a large inner diameter behind the first orifice (13), The cushioning member 19 made of syntactic foam, the protective film member 21 arranged on the front surface of the cushioning member, and the second member which is arranged close to the front surface of the protective film member and has a sufficiently small hole diameter.
The first orifice 13 is made gentle by setting the hole diameter of the first orifice 13 to be sufficiently large and the hole diameter of the second orifice 27A to be sufficiently small. The second orifice 27A serves as a strong throttle without damaging the resin pipe even when it acts as a throttle, and contributes to the damping action of the water hammer peak value.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention relates to a water hammer preventive device for protecting pipes, faucet equipment, hydraulic machinery, etc. from so-called water hammer action, and particularly for buffering water hammer in steel pipes as well as noise prevention in resin pipes for sheath pipe header construction method. Regarding excellent things.

[0002]

[Prior art]

 For example, in the case of water pipes, when there is a sudden power outage during operation of the water supply pump, the impeller inside the pump and the entire pipe are suddenly overloaded. This phenomenon is known as water hammer (water hammer) due to the inertial force of water. Recently, this water hammer effect has been frequently experienced even in ordinary households because single-lever type faucets that can open and close the valve with one touch by operating a single lever up and down are widely used. In addition, the water hammer of the fully automatic washing machine and the water pipe of the flush toilet also cause water hammer due to the sudden closing of the valve. These are becoming social noise problems, especially in apartments and condominiums. Therefore, a large number of water hammer prevention devices and compact and effective water hammer prevention devices that combine a bellows, a spring, and a cushioning material have been proposed.

[0003]

[Problems to be solved by the device]

 Under such circumstances, it has been known to use silicone rubber or silicone gel as a cushioning material (Japanese Patent Laid-Open No. 3-186691). However, it was found that the peak value of impact could not be reduced as expected by using the above-mentioned cushioning material, and various trials were conducted, and a specific syntactic foam was used as the cushioning material, and By arranging an orifice on the front side, it is possible to reduce the peak value of impact, and further, the needle-like holes are opened in the above-mentioned syntactic foam in a short time due to the water pressure flow ejected from the orifice, and the initial performance is maintained. We have found that the problem of being unable to do so can be dealt with by forming a stretchable protective film on the surface of the cushioning material, and have already filed patent applications for these.

By the way, although it has been confirmed that these water hammer preventers can exhibit desired functions for conventional water supply pipes made of steel pipe, etc., in recent years, the sheath pipe header construction method adopted in apartment houses and the like has been adopted. New problems are occurring for resin pipes. In other words, the sheath pipe header method is a method in which a resin pipe is piped from the header into the sheath pipe that has been laid in advance in a slab, lightweight concrete, or in a wall. It is not completely fixed inside, and there is a gap between them. Therefore, the resin pipe vibrates due to the water hammer effect generated in the resin pipe, and hits the sheath pipe to generate noise.

The above-mentioned conventional water hammer preventer cannot sufficiently cope with such a phenomenon. That is, assuming that the hole diameter of the inlet orifice is set small and the hardness of the cushioning material is also suitable for shock wave absorption of the steel pipe, when applied to a resin pipe, the resin pipe vibrates first before the cushioning material is used. As a result, shock waves directly act on the cushioning material and the effect of reducing the peak value of shock cannot be obtained if the hole diameter of the inlet orifice is simply increased. Met.

The present invention has been made on the basis of such a point, and an object of the present invention is to exert a function of reducing a peak value of impact when applied to a steel pipe, and also in a sheath header construction method. It is to provide a water hammer preventer capable of preventing noise when applied to a resin pipe.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the water hammer preventer according to claim 1 of the present invention is provided with a pipe or the like having a first orifice having a sufficiently large hole diameter at the inlet and a space portion having a large inner diameter behind it. It is formed by adding a main body case equipped with a connecting tool and a micro hollow body, which is arranged in the main body case behind the space portion and which has gel or rubber as a base material and an elastic outer shell, to the base material. Cushioning material made of syntactic foam, a membrane part disposed in front of the cushioning material and extending in a direction substantially orthogonal to the water hammer action direction, and extending in the water hammer action direction from around the membrane portion. A protective film member formed of a rubber-like elastic body and comprising a stretchable portion and a flange portion extending from the periphery of the stretchable portion, and a second member arranged close to the front surface of the protective film member and having a sufficiently small hole diameter. A perforated plate having a orifice and is characterized by comprising a.

A water hammer preventer according to a second aspect of the present invention is the water hammer preventer according to the first aspect, wherein the connecting tool has an inner diameter of 13 mm, the first orifice has a hole diameter of 9 mm, and the second orifice has a second orifice. The feature is that the hole diameter is 3 mm.

[0009]

[Action]

 According to the water hammer preventer of the first aspect, first, the shock wave due to the water hammer action is first attenuated by the first orifice and secondly attenuated by the second orifice of the perforated body, and finally buffered. It is damped by the material and undergoes a three-step damping action, which exerts the damping effect of suppressing the peak value of the water hammer action to a low level. The damping action of the first orifice and the second orifice is not exerted only by the presence of these orifices, but is the damping effect only exhibited by the fact that the cushioning material is arranged on the rear surface thereof. In other words, the damping action by the first orifice and the second orifice is considered to be energy consumption due to the inflow resistance of water and the formation of vortex due to the deformation of the buffer material, but the inflow resistance of water and the formation degree of vortex flow are Depending on the deformation, if the cushioning material is made of, for example, a solid body that does not contain the micro hollow body, a sufficient damping action cannot be obtained even if the first and second orifices are arranged facing this. In addition, the cushioning effect of the cushioning material is also due to the overall deformation of the gel or rubber as the base material, the deformation of the micro hollow bodies themselves dispersed in the base material, and the relative deformation between the micro hollow bodies in the base material. It is considered to be obtained by complex energy consumption due to changes in the positional relationship.

In the arrangement described above, by setting the hole diameter of the first orifice to be sufficiently large and the hole diameter of the second orifice to be sufficiently small, the first orifice becomes a gentle throttle and acts as a water hammer. It is considered that the resin orifice does not vibrate first, and the second orifice becomes a strong throttle and contributes to the damping action of the water hammer peak value.

Further, since the buffer material protects the syntactic foam formed by adding a micro hollow body having a gel or rubber as a base material and an elastic outer shell to the base material by a stretchable protective film, There is no perforation due to water hammer, the protective film member is made of rubber-like elastic material, and the stretchable part that expands and contracts in the water hammer action direction is formed. Since it absorbs, the main body case can be strongly crimped at the flange, water-tightness that can withstand high pressure is obtained, and damage to the protective film member and eventually the cushioning material is prevented to reduce the peak value of the prescribed impact over a long period of time. It is possible to obtain durability that maintains basic performance to be reduced. Further, since it is processed into a small diameter column, a compact water hammer preventer can be constructed.

According to the water hammer preventer of claim 2 of the present invention, the optimum hole diameter of the orifice is given, and when applied to the resin pipe of the sheath pipe header construction method, it has the effect of suppressing noise to a minimum and is applied to the steel pipe. In this case, the effect of suppressing the water hammer peak value to be small becomes remarkable.

[0013]

[Embodiment of device]

 An 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. This water hammer preventer 10 is composed of a main body case 15 having a connecting tool 11 as a whole configuration, and a screw portion 11A provided on the connecting tool 11 is provided to a branch connecting tube 2 provided on the way of the water pipe 1. It is installed by screwing. The connecting tool 11 has a first orifice 13 attached to its inlet, a space portion 14 having a large inner diameter formed behind it, and a flange portion 11B formed further above. The inner diameter of the space portion 14 is 13 mm as a standard, corresponding to the nominal diameter 10A to 15A of the pipe most effectively applied to the present invention, but as shown in the figure, it is further stepped. There may be an enlarged portion. The flange portion 11B is capped with a cylindrical main body case 15 having an opening at the lower side, and in the main body case 15, gel or rubber is used as a base material 17 and a micro hollow having an elastic outer shell. A cushioning material 19 made of syntactic foam formed by adding the body 17A is attached (filled). In the test example, the size of the cushioning material 19 is a column having a diameter of 40 mm and a height of 29 mm, and is quite small and compact.

A protective film member 21 is disposed in close contact with the front surface of the cushioning material 19 (on the opening side of the main body case 15), and a protective film of the cushioning material 19 facing the first orifice 13 of the connector 11 is provided. A perforated plate body 27 having a second orifice 27A is arranged close to the front surface of the member 21.

Then, the peripheral portion 15A of the main body case 15 is integrated with the flange portion 11B of the connector 11 by caulking with the flange portion 21C of the protective film member 21 and the peripheral portion of the perforated plate body 27 sandwiched therebetween. ing. That is, the flange portion 11B is provided with a groove portion 11C in the circumferential direction, the O-ring 12 is fitted therein, and the peripheral portion 15A of the main body case 15 is pushed into the groove portion 11C to crush the O-ring 12 so that caulking is performed. . It has been confirmed that such a structure can maintain durability and watertightness against water pressure applied to the inside.

Next, details of the physical properties of the syntactic foam forming the cushioning material 19 will be described. The syntactic foam referred to in the present application is formed by using a gel or rubber as a base material 17 and adding a micro hollow body 17A having an elastic outer shell, and is also called a synthetic foam. Preferably, a silicone syntactic foam is used. In this case, as the silicone gel or silicone rubber, those having a rubber hardness in the range of 200 according to JIS K 2207 (load of 50 g) to about 50 in accordance with JIS K 6301 can be applied. It is a micro hollow sphere of μm to 1,000 μm, and this is added with about 1 to 6%.

A suitable silicone rubber is CX52-282 manufactured by Toray Dow Corning Silicone Co., Ltd. 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 according to SRIS 0101 (Japan Rubber Association standard) or JIS S 6050 which is specified as being suitable for measuring rubber, foamed elastomer, sponge, etc. that is softer than the rubber hardness according to JIS K 6301. Is. 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 should satisfy the basic physical properties such as having the above hardness, excellent temperature characteristics, no worries about elution, no deterioration, and durability. If applicable, it can be applied.

Further, the micro hollow body to be added is a micro hollow body having a shell of an elastic synthetic resin capable of self-elastic deformation and having a diameter of several tens of μm to 1,000 μm, which is preferable. Examples thereof include Expancel (registered trademark) manufactured by Nippon Philite Co., Ltd. and Matsumoto Microsphere manufactured by Matsumoto Yushi-Seiyaku Co., Ltd. In a test example described later, Matsumoto Microsphere 80EDL (diameter 200 μm) is used.

In general, these micro hollow bodies having a size of about 5 μm to 100 μm are commercially available as a general grade. However, it is preferable to improve the micro hollow bodies to expand them to a size of about 200 μm to 1000 μm. Theoretically, it is expected that the material expanded to about 1000 μm will have a better buffering effect, but in reality, in order to expand it to about 1000 μm, it is necessary to increase its shell thickness. The result of 200 μm to 300 μm showing excellent buffering effect has been obtained.

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

The shape of the protective film member 21 includes a film portion 21A extending on the surface of the cushioning material 19 in a direction substantially orthogonal to the water hammer action direction, and a water hammer action from the periphery of the film portion 21A. It is formed of a stretchable portion 21B extending in the direction and a flange portion 21C extending from the periphery of the stretchable portion 21B, and has a so-called top hat shape. Also, the plate thickness of this one absorbs the water hammer energy and is dented and displaced together with the cushioning material 19. When the water hammer energy disappears, the restoring force of the cushioning material 19 and its own restoring force return together. As described above, the condition is set to about 5 mm.

The portion of the protective film member 21 excluding the expansion / contraction portion 21B is in close contact with the cushioning material 19, the main body case 15, and the perforated plate body 27 by caulking, but these are adhered with an adhesive or the like. May be. That is, since the water hammer pressure acts between the protective film portion 21A and the cushioning material 19, a negative pressure is instantaneously generated. Therefore, the protective film portion 21A and the cushioning material 19 are integrated so as not to separate from each other. Good. Further, in order to prevent water from entering the cushioning material 19 side between the flange portion 21C and the main body case 15 and between the flange portion 21C and the perforated plate body 27, even if they are adhered with an adhesive. Good.

Next, when it is applied to a steel pipe, it exerts a function of lowering the peak value of impact and is important for preventing noise when applied to a resin pipe in a sheath pipe header construction method. The hole diameter of the orifice will be described in detail. In the present invention, the hole diameter of the first orifice 13 is set sufficiently larger than usual, while the hole diameter of the second orifice 27A is set sufficiently small. The steel pipe and the resin pipe to which the water hammer preventer of the present invention is most effectively applied have a nominal diameter in the range of 10A to 15A, and the inner space of the connector has an inner diameter of about 13 mm. On the other hand, making the hole diameter of the first orifice sufficiently large means that the hole diameter is close to the inner diameter, for example, about 9 mm. Further, making the hole diameter of the second orifice sufficiently small means setting a size having a large difference from the above inner diameter, for example, about 3 mm. With such a setting, it is possible to lower the peak value of impact on the steel pipe and suppress the generation of noise on the resin pipe of the sheath pipe header method.

Next, the test conducted by the applicant to obtain an appropriate orifice hole diameter will be described. First, when applied to the resin pipe in the sheath pipe header construction method, the noise prevention effect was tested by connecting to a water hammer prevention effect evaluation device 60 as shown in FIG. Explaining the above apparatus, the water supply system 61 is composed of a pipe 65 to be supplied with water from a pressure pump 63. The pipe 65 is formed by inserting a resin pipe 69 inside the sheath pipe 67. The pipe 65 has a flow meter 71, a pressure gauge 73, a solenoid valve 75, and a pressure control valve 77. The water hammer preventer 10 of the present invention is branched and connected between the pressure gauge 73 of the pipe 65 and the solenoid valve 75.

First, a sensitivity test by a human ear was conducted using the above device. As shown in FIG. 3, a matrix was set in which the hole diameter of the first orifice 13 was 4, 6, 9 mm and the hole diameter of the second orifice 27A was 9, 6, 3 mm. The sound emitted by the resin pipe 69 striking the sheath pipe 67 when a striking action was generated was judged by a plurality of persons, large, medium and small. As a result, it was confirmed that the sound decreased in the direction of the arrow in the figure.

Therefore, as a precaution, the hole diameter of the second orifice 27A is fixed to 3 mm, and the hole diameter of the first orifice 13, which has been previously confirmed to exhibit excellent performance in a steel pipe, is set to 4 mm. Then, the sound level meter 79 was attempted to measure two types of the first orifice 13 having a hole diameter of 9 mm. The sound level meter was installed at a position 1 meter laterally and 50 cm high in the place with the largest vibration in the piping shown in Fig. 2, and measurements were performed on a resin pipe 69 with a nominal diameter of 10 A, which is more prone to noise ( A characteristic).

As a result, as shown in FIG. 4, the first orifice 13 having a hole diameter of 9 mm showed the lowest noise level at 63 decibels. On the other hand, when the diameter of the first orifice 13 was 4 mm, the noise was large at 64 decibels.

From the above test results, the hole diameter of the first orifice 13 should be set to 9 mm, which is sufficiently large (close to the inner diameter), and the second orifice should be set to 3 mm, which is sufficiently small (which has a large difference from the inner diameter). It was confirmed that the product has an excellent noise prevention effect.

Further, in order to confirm whether or not the above-described one has a shock buffering effect on the steel pipe, the impact peak value in the steel pipe was measured again by connecting to the water hammer prevention effect evaluation device 40 shown in FIG. Explaining the above apparatus, the water supply system 41 is composed of a pipe 45 supplied with water from a pressure pump 43, and the pipe is a steel pipe. The pipe 45 has a pressure adjusting valve 47, a check valve 48, a quick closing valve 49, and a flow rate adjusting valve 51. The water hammer preventer 10 of the present invention is connected between the check valve 48 and the quick closing valve 49 of the pipe 45 through a branch pipe. A branch pipe 55 is connected to the upstream side of the water hammer preventer 10, and a pressure sensor 57 and an FET analyzer 59 connected to the pressure sensor 57 are provided here. By the test apparatus, the reference pressure from 1.5 kgf / cm ² for the two types of water hammer arrestor to 6 kgf / cm ² 1. The water hammer peak value was measured by changing every 5 kgf / cm ² .

As a result, as shown in FIG. 6, the first orifice 13 having a hole diameter of 4 mm showed the lowest water hammer peak value for each reference water pressure. It was confirmed that the one set to 9 mm also showed a water hammer peak value similar to that of the one with a pore diameter of 4 mm, and had an excellent water hammer buffering effect.

According to the embodiments of the present invention described above, the following effects can be obtained. First, according to this water hammer preventer, the water hammer energy is primarily attenuated by the first orifice 13, secondly attenuated by the second orifice 27A of the perforated plate 27, and finally damped by the cushioning material 19. Therefore, the water hammer energy is attenuated in three steps, and the water hammer peak value is kept 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 the conventional one can be exerted. 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 the protective film member 21. There is no perforation and its durability is guaranteed.

Further, the protective film member 21 is formed of a rubber-like elastic body, and further, an expanding / contracting portion 21B is formed which expands / contracts in the water hammering direction, and the tensile force due to the water hammer action is absorbed by the expanding / contracting portion 21B. As a result, the connector 11 and the body case 15 can be strongly caulked at the flange portion 21C, water-tightness that can withstand high pressure can be obtained, and damage to the protective film member 21 can be effectively prevented. , Durability that maintains the basic performance of reducing the peak value of a given shock over a long period of time is obtained.

Then, by setting the hole diameter of the first orifice to be sufficiently large and the hole diameter of the second orifice to be sufficiently small, the first orifice will be gently throttled, and the resin pipe of the sheath pipe header method will be obtained. When applied, it has the effect of suppressing noise to a small extent, and when applied to steel pipes, it has the effect of suppressing the water hammer effect by suppressing the water hammer peak value to a small value.

The present invention is not limited to each of the above-described embodiments, and it goes without saying that design changes in details can be freely made within the scope of the invention. For example, the shapes of the connector 11, the main body case 15, the cushioning material 19, and the like can be changed, and the configurations of the first orifice 13 and the second orifice 27A are arbitrary. In the present invention, the term “orifice” means that even if it does not have an orifice portion of a diaphragm plate, it is sufficient if it is provided with a hole to substantially restrict the fluid. It does not need to be a body, and may be formed integrally with the connector and the body case. Further, the shape of the protective film member is not limited to the top hat shape shown in the figure, but may be any shape having an expanding / contracting portion extended in the water hammer action direction, and may be, for example, a straw hat shape. . Also, the surface shape of the cushioning material may be concave or convex in view of the close contact between the protective film member and the cushioning material. Although the water hammer preventer of the present invention has been applied to water, it can be applied to liquids other than water.

[0035]

【effect】

 As described above in detail, according to the water hammer preventer of claim 1 of the present invention, the water hammer energy is primarily attenuated by the first orifice and secondly attenuated by the second orifice of the perforated body. Finally, since it is attenuated by the cushioning material, the water hammer energy is attenuated in three steps, the water hammer peak value is suppressed to a low value, and the noise is prevented. Also, since the above-mentioned cushioning material is processed into a small diameter column, a compact water hammer preventer can be constructed. In addition, since the above-mentioned cushioning material has a protective film member coated with syntactic foam formed by adding a micro hollow body having a gel or rubber as a base material and an elastic outer shell to the base material, it is exposed by a water hammer. It is durable and its durability is guaranteed.

Further, the protective film member is formed of a rubber-like elastic body, and further, an expanding / contracting portion that expands / contracts in the water hammer action direction is formed, and the tensile force due to the water hammer action is absorbed by the elastic member. Therefore, it is possible to strongly crimp the connector and the main body case at the flange part, to obtain watertightness that can withstand high pressure, to effectively prevent damage to the protective film member, and to prevent a prescribed impact over a long period of time. It is possible to obtain the durability that maintains the basic performance of reducing the peak value of.

Then, by setting the hole diameter of the first orifice to be sufficiently large and the hole diameter of the second orifice to be sufficiently small, the effect of suppressing the noise to be small when applied to the resin pipe of the sheath pipe header construction method is obtained. In addition, when applied to steel pipes, the water hammer effect can be suppressed by suppressing the water hammer peak value to a small value, and a water hammer preventer that can be used for both is obtained.

According to the water hammer preventer of claim 2 of the present invention, the optimum hole diameter of the orifice is given, and when applied to the resin pipe of the sheath pipe header construction method, it has the effect of suppressing noise to a minimum and is applied to the steel pipe. In this case, there is an effect that a water hammer preventer that can significantly reduce the water hammer peak value can be obtained.

[Brief description of drawings]

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

FIG. 2 is a front view of a water hammer prevention effect evaluation device.

FIG. 3 is a view showing an embodiment of the present invention, and is a view showing a matrix of hole diameters of the first orifice and the second orifice.

FIG. 4 is a diagram showing an embodiment of the present invention and is a diagram showing a noise level of a water hammer preventer.

FIG. 5 is a front view of a water hammer prevention effect evaluation device.

FIG. 6 is a view showing an embodiment of the present invention, and is a view showing a water hammer peak value of a water hammer preventer.

[Explanation of symbols]

 1 Water Pipe 2 Branch Connection Pipe 10 Water Hammer Preventer 11 Connection Tool 11A Screw Part 13 First Orifice 14 Space Part 15 Main Body Case 17 Base Material 17A Micro Hollow Body 19 Buffer Material 21 Protective Membrane Member 21A Membrane Part 21B Expandable Section 21C Flange Part 27 Perforated body 27A Second orifice 40 Water hammer prevention effect evaluation device 60 Water hammer prevention effect evaluation device

Claims (2)

[Scope of utility model registration request] 1. A first with a sufficiently large hole diameter set at the inlet.
A main body case having an orifice and a fitting for connection with a pipe or the like having a space portion with a large inner diameter behind it, and a gel or rubber as a base material disposed inside the main body case and behind the space portion. A cushioning material made of syntactic foam formed by adding a micro hollow body having an elastic outer shell to the membrane, and a membrane portion disposed in front of the cushioning material and extending in a direction substantially orthogonal to the water hammer action direction. And a protective film member formed of a rubber-like elastic body, which comprises an elastic part extending from the periphery of the film part in a water hammer action direction and a flange part extending from the periphery of the elastic part, and a protective film member of the protective film member. A water hammer preventer, comprising: a perforated body having a second orifice arranged close to the front surface and having a sufficiently small hole diameter. 2. The water hammer preventer according to claim 1, wherein the connecting tool has an inner diameter of 13 mm, the first orifice has a hole diameter of 9 mm, and the second orifice has a hole diameter of 3 mm. Water hammer preventer.