JPH08145272A - Water hammer preventing device - Google Patents

Abstract

PURPOSE: To perform proper absorption of a pressure wave by a method wherein inflow of a pressure wave to the interior of a water chamber is rendered rapid as a venturi effect is improved and contraction of a water chamber consisting of a diaphragm to receive a pressure wave is reliably performed. CONSTITUTION: Formation of a water hammer preventing device A is such that a venturi 5 is located in a cylinder body connected in a tubular manner to a coupling in the middle of a piping and a communication port 6 is opened to the necking part 5a of the venturi, and communicated with a water chamber W consisting of a diaphragm attached to a cylinder body. The communicating port 6 opened to the necking part of the venturi is formed in an oblong shape wherein a bore R along the peripheral direction of the inner peripheral surface of the venturi is short and a bore along the axial direction of the venturi is long.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to connect a pipe for circulating a liquid such as cold water, hot water, oil, etc., and to rapidly close an on-off valve such as a faucet connected to the pipe. Water hammer prevention that absorbs the pressure wave (water hammer) generated when the flow of liquid in the pipe suddenly stops due to, for example, preventing the water hammer from destroying the piping equipment Regarding improvements to the device.

[0002]

2. Description of the Related Art By connecting in the middle of a pipe, a pressure wave (water hammer) generated in the pipe is absorbed to prevent the pipe equipment from being damaged by the water hammer. As shown in FIG. 1, the water hammer prevention device is provided with an air chamber 11 separated by a diaphragm 10 in an expansion tank 1 connected to a pipe a in a side branch shape, and a compressed air There is a means for relaxing the peak of the pressure wave by causing the air chamber 11 to be compressed through the diaphragm 10 by the pressure when a pressure wave is generated in the pipe a. Further, as shown in FIG. 2, the piston 20 is fitted in the cylinder 2 connected to the pipe a in a side branch shape,
The piston 20 is pushed down by the spring 21, and the pipe a
When a pressure wave is generated in the inside, there is a means for relaxing the peak of the pressure wave by pushing up the piston 20 against the bias of the spring 21 by the pressure.

Further, as shown in FIG. 3, a tube 30 made of an elastic material such as a rubber material is fitted in an inner cylindrical shape on the inner surface side of a cylindrical case 3 which is connected in the middle of a pipe a in a tubular joint shape. The sponge 31 is inserted between the outer peripheral surface of the tube 30 and the inner peripheral surface of the cylindrical case 3 so that when a pressure wave is generated in the pipe a, the pressure is applied to the tube. Three
There is a means for 0 to expand while crushing the sponge 31 to absorb the pressure.

The above-mentioned conventional water hammer preventing means, in the means using the expansion tank 1 shown in FIG. 1, is difficult to attach to the built-in pipe of the equipment because the large expansion tank 1 is used. In addition, there is a problem in that it becomes expensive, and the piston 20 shown in FIG.
In the means for moving against the pressure of 1, the cylinder 2 is connected to the pipe a in a side branch shape, so that it is difficult to attach the cylinder 2 to the built-in pipe of the device, like the means of FIG. Moreover, there is a problem that the pressure wave absorption capacity is low, and as shown in FIG.
With the means shown in (1), there is a problem that the effect becomes small in a place where there is a pressure fluctuation, and it is difficult to adjust the pressure to be suitable for the water pressure.

As a measure against this problem, the applicant of the present invention has provided a venturi 5 in a tubular tubular body 4 of a joint which is connected in the middle of a pipe a as shown in FIG. 4 or 5.
A communication port 6 is opened in the entangled portion 5a, and a water chamber W communicating with the communication port 6 is formed by a flexible diaphragm 7 so as to expand and contract, and as shown in FIG. A means for constructing the water hammer preventing device has been developed by attaching it to the outer circumference or attaching it to the tubular body 4 in a branch tubular shape as shown in FIG.

In this means, when the flow in the pipe a is stopped, the pressure of the water or hot water supplied into the pipe a causes the water or hot water to enter the water chamber W from the communication ports 6 ... 5, the diaphragm 7 is in an expanded state as shown by the chain line in FIG. 5 and as shown in FIG. 6, and the inside of the water chamber W is thereby supplied with water (or hot water) in the pipe a. Is held at the same pressure as.

Next, when there is a water supply flow in the pipe a, the water supply flow is the entangled portion 5 of the venturi 5.
By virtue of the Venturi effect of flowing a through at a high speed, the water chamber W has a negative pressure, so that the water in the water chamber W is sucked out to the pipe a side, and the diaphragm 7 contracts. 5
As shown by the solid line, the state of contacting the outer peripheral surface of the venturi 5 is reached.

Next, when the water tap or hot water tap provided on the downstream side of the pipe a is suddenly closed in this state, the venturi effect due to the entangled portion 5a of the venturi 5 disappears. The negative pressure in the water chamber W disappears.

As a result, the water in the pipe a flows into the water chamber W from the above-mentioned communication port 6 ... And expands the diaphragm 7. Therefore, the flow in the pipe a is not stopped until the inflow into the diaphragm 7 is stopped, and is stopped when the inflow is stopped. Therefore, the water tap / hot water tap is suddenly closed. However, the water hammer phenomenon does not occur on the upstream side of the water hammer prevention device A.

Further, by forming the diaphragm 7 so that it does not contract from its expanded state by itself,
It is also possible to prevent the recoil water hammer phenomenon caused by returning by itself.

[0011]

The above-mentioned means can improve the efficiency of absorbing the pressure wave by increasing the diameter of the communication port 6 opened in the entangled portion 5a of the venturi 5. However, when the diameter of the communication port 6 is increased, the Venturi effect is lowered, and the water chamber W composed of the diaphragm 7 cannot be contracted, resulting in a decrease in the function of absorbing the pressure wave. Become.

Therefore, by improving the absorption of pressure waves,
There is a problem that improving the Venturi effect works against each other, and it is difficult to satisfy both.

The present invention has been made in order to solve this problem, and improves the Venturi effect to ensure that the water chamber W formed of the diaphragm 7 for receiving the pressure wave is contracted. It is an object of the present invention to provide a new means for promptly inflowing a pressure wave into the water chamber W and appropriately absorbing the pressure wave.

[0014]

In the present invention, as a means for achieving the above-mentioned object, a venturi is provided in a tubular body connected in a joint tubular shape in the middle of a pipe,
In a water hammer prevention device that opens a communication port at its kerf and communicates with a water chamber made up of a diaphragm attached to the cylindrical body, a communication port to be opened at the kerf of the venturi is provided on the inner surface of the venturi. The present invention provides a water hammer prevention device characterized in that it is formed in an elongated hole shape having a small diameter along the circumferential direction and a long diameter along the axial direction of a venturi.

[0015]

According to the means of the present invention configured as described above, the communication port 6 which is opened in the entangled portion 5a of the venturi 5 is formed in the shape of an elongated hole having a small diameter in the radial direction of the venturi 5 and long in the axial direction of the venturi 5. Therefore, since the water flow passing through the entangled portion 5a of the venturi 5 is affected only to the same extent as the small-diameter communication port 6 in the conventional means, when the small-diameter communication port 6 is opened. As described above, a favorable Venturi effect is maintained by the water flow passing through the entangled portion 5a at a high speed, and the water chamber W including the diaphragm 7 is reliably contracted.

When a water tap or hot water tap provided on the downstream side of the pipe a is suddenly closed to generate a pressure wave, the pressure wave propagates to the entangled portion 5a of the venturi 5 and there. When pressure is introduced into the water chamber W formed by the diaphragm 7 from the communication port 6 provided in the communication port 6, the communication port 6 is formed to be long in the axial direction of the venturi 5, and thereby the opening area is increased. By making it several times larger, the pressure is made to flow into the water chamber W several times faster than in the case where the conventional small-diameter communication port 6 is provided, and the pressure wave Increases the absorption effect.

[0017]

Embodiments Next, embodiments will be described in detail with reference to the drawings. In the drawings, the same reference numerals are used for components having the same effects as those of the conventional means.

FIG. 7 shows an outer peripheral surface of a venturi 5 and a cylindrical body 4 in which a water chamber W made of the diaphragm 7 and a diaphragm accommodating chamber Y for accommodating the water chamber W made of the diaphragm 7 are incorporated in the cylindrical body 4. FIG. 1 is a vertical sectional side view of a water hammer prevention device A according to the present invention which is installed between the inner peripheral surface of a peripheral wall and the inner peripheral surface of the peripheral wall. In FIG.
A communication port opened in the sloping portion 5a, 7 is a diaphragm forming a water chamber W, and Y is a diaphragm accommodating chamber accommodating the water chamber W made of the diaphragm 7.

The tubular body 4 is formed in a pipe shape, and on the upper end side which is one end side in the axial direction of the tubular body 4, a joint having a diameter corresponding to the inner diameter of the pipe a formed smaller than the body portion 4a. A pipe portion 40 is formed, and a through hole 41 having a diameter corresponding to the inner diameter of the pipe a is formed on the lower end side which is the other end side in the axial direction. A connection pipe 42 formed separately is connected and connected to the through hole 41 so as to extend the cylinder 4 downward, and a connection pipe portion 4 for connecting the pipe a to the lower end of the connection pipe 42.
3 is formed. Further, an air hole 44 is formed in the peripheral wall of the body portion 4a of the cylindrical body 4 so that the diaphragm accommodating chamber Y formed inside thereof can communicate with the outside.

The venturi 5 is of a normal type in which a shaft portion is formed in a tubular shape and a entangled portion 5a is formed in its inner cavity, and the outer diameter thereof is formed so as to correspond to the diameter of the connecting pipe portion 40. hand,
The tube 4 is inserted into the tube 4 through the through hole 41 on the lower end side, and a separate connecting tube 42 is attached to the lower end of the tube 4 so that the tube 4 is integrated into the tube 4. Thereby, a diaphragm accommodating chamber Y is formed between the outer peripheral surface of the venturi 5 and the inner peripheral surface of the body portion 4a of the cylindrical body 4, and the diaphragm 7 forming the water chamber W is accommodated therein. . Further, the entangled portion 5a formed in the inner cavity of the venturi 5 is formed at a portion closer to the upper end side in FIG. 7, which is the upstream side of the water flow flowing in the pipe a.

The entangled portion 5a of the venturi 5
As shown in FIG. 8, the communication port 6 to be opened is formed in an elongated hole in which the diameter R in the circumferential direction of the venturi 5 is narrowed and the diameter L in the axial direction of the venturi 5 is increased. The base end side thereof is open to the water chamber W composed of the diaphragm 7 arranged so as to surround the outer periphery of the venturi 5.

The septum 7 is a usual one formed by molding a rubber material, a synthetic resin material, a metal material or the like into a bellows shape and expanding and contracting, and is formed in a tubular shape with both axial ends open. The axial direction of the venturi 5 is aligned with the axial direction of the venturi 5, and the venturi 5 is fitted on the outer peripheral side of the venturi 5, and the openings at both ends in the axial direction are watertightly fixed to the outer peripheral surface of the venturi 5. Then, in that state, it is inserted into the tubular body 4 together with the venturi 5 and the joint pipe 42 is assembled to the lower end side of the tubular body 4, so that the joint pipe 42 is assembled to the tubular body 4 as an assembly fitting. It is attached.

In the above-mentioned example, the diaphragm 7 that expands and contracts to form the water chamber W is attached to the cylindrical body 4 by covering the outer circumference of the venturi 5 with the diaphragm 7 in a sheath shape. However, the present invention is not limited to this example, and the diaphragm accommodating chamber Y is projected from the side surface of the tubular body 4 in a side branch shape like the conventional means shown in FIG. As in the case of installing the water chamber W made of the diaphragm 7 in the inside, the venturi 5 and the water chamber W may be separately installed in the tubular body 4.

FIG. 9 shows a diaphragm accommodating chamber Y in order to prevent a water hammer phenomenon of recoil caused by a sudden return of the diaphragm 7 when the diaphragm 7 is formed so as to return to the contraction side by a self-made force such as stainless steel. The valve mechanism 8 attached to the air hole 44 that communicates with the outside air is shown. This valve mechanism 8
When the water chamber W made of the diaphragm 7 contracts into the air hole 44 and the outside air is sucked into the diaphragm accommodating chamber Y, the air hole 44 is closed so that the pressure in the diaphragm accommodating chamber Y is lower than that of the diaphragm 7. Water chamber W
The valve 81 biased toward the valve closing side by the spring 80 so that the valve 81 is opened by the pressure when it rises due to the expansion, and when the valve 81 is closed, the diaphragm chamber Y is slightly vented to the outside air. And a bypass passage 82 having a small diameter. As a result, when the outside air is sucked into the diaphragm storage chamber Y due to the contraction of the water chamber W formed by the diaphragm 7, the outside air is delayed inflow to prevent the water hammer phenomenon due to the recoil of the return. is there.

The valve mechanism 8 provided in the air hole 44 has a structure in which the diaphragm 7 forming the water chamber W is formed by a rubber material or the like.
In order to avoid the rapid expansion, as shown in FIG. 10, the biasing direction of the spring 80 with respect to the valve 81 is reversed, and when the air is discharged from the diaphragm accommodating chamber Y, the bypass passage 82 having a small diameter is used. In some cases, the air may be discharged slowly.

[0026]

As described above, in the water hammer prevention device according to the present invention, the venturi 5 is provided in the tubular body 4 which is connected to the joint pipe in the middle of the pipe a, and the bent portion 5a thereof is provided. The communication port 6 to be opened is made to communicate with the water chamber W formed by the diaphragm 7 so as to be expandable and contractable, and the water chamber W is kept in a contracted state by the water flow flowing in the pipe a. When a pressure wave is generated due to abrupt closure of the water tap or hot water tap connected to a, the pressure of the pressure wave is formed by the diaphragm 7 via the communication port 6 provided in the entangled portion 5a of the venturi 5. When the pressure wave is absorbed by flowing into the water chamber W, the communication port 6 provided in the entangled portion 5a of the Venturi 5 has a narrow diameter R in the circumferential direction of the inner peripheral surface of the entangled portion 5a. Since it is formed in the shape of an elongated hole with a long diameter L The venturi effect, while the as in the case where a smaller diameter of the hole 6 well, so may the good absorption of the pressure wave by the opening area of the substantial hole 6 increases.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a conventional water hammer prevention device.

FIG. 2 is a vertical sectional side view of another example of the conventional water hammer prevention device.

FIG. 3 is a vertical sectional side view of still another example of the conventional water hammer prevention device.

FIG. 4 is a vertical sectional front view of a different example of a conventional water hammer prevention device.

FIG. 5 is a vertical sectional side view of a modified example of the above water hammer preventing device.

6 is an explanatory view of the operation of the water hammer prevention device of FIG.

FIG. 7 is a vertical sectional front view of the water hammer prevention device according to the present invention.

FIG. 8 is an enlarged vertical sectional front view of a main part of the above water hammer prevention device.

FIG. 9 is a vertical sectional front view of a portion of the above water hammer preventing device.

FIG. 10 is a vertical cross-sectional side view of a modified example of the same portion of the above water hammer prevention device.

[Explanation of symbols]

A ... Water hammer prevention device, a ... Piping, W ... Water chamber, Y ... Diaphragm accommodating chamber, RL ... Caliber, 1 ... Expansion tank,
10 ... Diaphragm, 11 ... Air chamber, 2 ... Cylinder, 2
0 ... Piston, 21 ... Spring, 3 ... Case, 30 ... Tube, 31 ... Sponge, 4 ... Cylindrical body, 4a ... Body, 40 ... Joint pipe part, 41 ... Through hole, 42 ... Joint pipe, 43 ... Connection pipe Department,
44 ... Air hole, 5 ... Venturi, 5a ... Tangled part, 6 ...
Communication port, 7 ... diaphragm, 8 ... valve mechanism, 80 ... spring, 81 ...
Valve, 82 ... Bypass passage.

Claims (1)

[Claims] 1. A venturi 5 is provided in a tubular body 4 connected in the form of a joint pipe in the middle of a pipe a, and a communication port 6 is opened in a entangled portion 5a of the venturi 5 to form a diaphragm 7 attached to the tubular body 4. In the water hammer prevention device that communicates with the water chamber W, the communication port 6 that is opened in the entangled portion 5a of the venturi 5 has a small diameter R along the circumferential direction of the inner peripheral surface of the venturi 5 and a diameter along the axial direction of the venturi 5. A water hammer prevention device characterized in that L is formed in a long hole shape.